I'm working on a Window Forms application in Visual Studio, and I'm using a custom settings object to keep track of some application settings.
The user can change these settings through the PropertyGrid widget.
This works great for string and integer values, but now I also want to add a List<string> variable, so the user can enter a list of keywords.
I've added the List<string> variable to the settings object and I've added a TypeConverter to show it as a comma separated string representation in the PropertyGrid. Without the TypeConverter the value would display as just (Collection). It is displayed correctly and I can edit it, see screenshot below
this._MyProps = new PropsClass();
this._MyProps.ReadFromIniFile("mysettings.ini");
propertyGrid1.SelectedObject = this._MyProps;
Now I also want to write and read these setting to a settings.ini file, so I've added SaveToIniFile and ReadFromIniFile methods to the object. This works for string and integer values, except the List<string> is not saved and loaded to and from the .ini file correctly. When I call SaveToIniFile the content mysettings.ini is for example this, still using the "(Collection)" representation and not the values entered by the user:
[DataConvert]
KeyWordNull=NaN
ReplaceItemsList=(Collection)
YearMaximum=2030
So my question is, how can I save/load a List<string> setting to an ini file while also allowing the user to edit it in a PropertyGrid?
I know it'd have to convert from a string to a List somehow, maybe using quotes around the string to inclkude the line breaks, or maybe just comma-separated back to a list of values? But anyway I thought that is what the TypeConverter was for. So why is it showing correctly in he PropertyGrid but not in the ini file? See code below
The custom settings properties object:
// MyProps.cs
public class PropsClass
{
[Description("Maximum year value."), Category("DataConvert"), DefaultValue(2050)]
public int YearMaximum { get; set; }
[Description("Null keyword, for example NaN or NULL, case sensitive."), Category("DataConvert"), DefaultValue("NULL")]
public string KeyWordNull { get; set; }
private List<string> _replaceItems = new List<string>();
[Description("List of items to replace."), Category("DataConvert"), DefaultValue("enter keywords here")]
[Editor("System.Windows.Forms.Design.StringCollectionEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(UITypeEditor))]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
[TypeConverter(typeof(StringListConverter))]
public List<string> ReplaceItemsList
{
get
{
return _replaceItems;
}
set
{
_replaceItems = value;
}
}
and in the same PropsClass class, the write and read methods to save/load from a settings.ini file
[DllImport("kernel32.dll")]
public static extern int GetPrivateProfileSection(string lpAppName, byte[] lpszReturnBuffer, int nSize, string lpFileName);
public void SaveToIniFile(string filename)
{
// write to ini file
using (var fp = new StreamWriter(filename, false, Encoding.UTF8))
{
// for each different section
foreach (var section in GetType()
.GetProperties()
.GroupBy(x => ((CategoryAttribute)x.GetCustomAttributes(typeof(CategoryAttribute), false)
.FirstOrDefault())?.Category ?? "General"))
{
fp.WriteLine(Environment.NewLine + "[{0}]", section.Key);
foreach (var propertyInfo in section.OrderBy(x => x.Name))
{
var converter = TypeDescriptor.GetConverter(propertyInfo.PropertyType);
fp.WriteLine("{0}={1}", propertyInfo.Name, converter.ConvertToInvariantString(propertyInfo.GetValue(this, null)));
}
}
}
}
public void ReadFromIniFile(string filename)
{
// Load all sections from file
var loaded = GetType().GetProperties()
.Select(x => ((CategoryAttribute)x.GetCustomAttributes(typeof(CategoryAttribute), false).FirstOrDefault())?.Category ?? "General")
.Distinct()
.ToDictionary(section => section, section => GetKeys(filename, section));
//var loaded = GetKeys(filename, "General");
foreach (var propertyInfo in GetType().GetProperties())
{
var category = ((CategoryAttribute)propertyInfo.GetCustomAttributes(typeof(CategoryAttribute), false).FirstOrDefault())?.Category ?? "General";
var name = propertyInfo.Name;
if (loaded.ContainsKey(category) && loaded[category].ContainsKey(name) && !string.IsNullOrEmpty(loaded[category][name]))
{
var rawString = loaded[category][name];
var converter = TypeDescriptor.GetConverter(propertyInfo.PropertyType);
if (converter.IsValid(rawString))
{
propertyInfo.SetValue(this, converter.ConvertFromString(rawString), null);
}
}
}
}
// helper function
private Dictionary<string, string> GetKeys(string iniFile, string category)
{
var buffer = new byte[8 * 1024];
GetPrivateProfileSection(category, buffer, buffer.Length, iniFile);
var tmp = Encoding.UTF8.GetString(buffer).Trim('\0').Split('\0');
return tmp.Select(x => x.Split(new[] { '=' }, 2))
.Where(x => x.Length == 2)
.ToDictionary(x => x[0], x => x[1]);
}
}
and the TypeConverter class for the ReplaceItemsList property
public class StringListConverter : TypeConverter
{
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
{
if (value is List<string>)
{
return string.Join(",", ((List<string>)value).Select(x => x));
}
return base.ConvertTo(context, culture, value, destinationType);
}
}
The reason your type converter is not used is because of this line:
var converter = TypeDescriptor.GetConverter(propertyInfo.PropertyType);
You are getting the TypeConverter that is defined on the type of the property. So for ReplaceItemsList that would be the TypeConverter for List<T>. You need to get the TypeConverter for the property since that is where you added the TypeConverter attribute. So either you do something like you did for the category attribute in the read method where you use the PropertyInfo's GetCustomAttributes or you do what the PropertyGrid does which is use the PropertyDescriptors to get to the properties and their state. The latter would be better since if the object implemented ICustomTypeDescriptor or some other type augmentation like TypeDescriptionProvider then you would get that automatically.
So something like the following for the Save using PropertyDescriptors would be:
public void SaveToIniFile(string filename)
{
// write to ini file
using (var fp = new StreamWriter(filename, false, Encoding.UTF8))
{
// for each different section
foreach (var section in TypeDescriptor.GetProperties(this)
.Cast<PropertyDescriptor>()
.GroupBy(x => x.Attributes.Cast<Attribute>().OfType<CategoryAttribute>()
.FirstOrDefault()?.Category ?? "General"))
{
fp.WriteLine(Environment.NewLine + "[{0}]", section.Key);
foreach (var propertyInfo in section.OrderBy(x => x.Name))
{
var converter = propertyInfo.Converter;
fp.WriteLine("{0}={1}", propertyInfo.Name, converter.ConvertToInvariantString(propertyInfo.GetValue(this)));
}
}
}
}
If you are going to use a custom TypeConverter, you'll have to register it as a provider to TypeDescriptionProvider:
TypeDescriptor.AddProvider(new CustumTypeDescriptorProvider(), typeof(List<string>));
And in your implementation you could just do this in the constructor of PropsClass (instead of using the attribute). I created some custom code below that would do the split.
public class PropsClass
{
[DllImport("kernel32.dll")]
public static extern int GetPrivateProfileSection(string lpAppName, byte[] lpszReturnBuffer, int nSize, string lpFileName);
[Description("Maximum year value."), Category("DataConvert"), DefaultValue(2050)]
public int YearMaximum { get; set; }
[Description("Null keyword, for example NaN or NULL, case sensitive."), Category("DataConvert"), DefaultValue("NULL")]
public string KeyWordNull { get; set; }
private List<string> _replaceItems = new List<string>();
[Description("List of items to replace."), Category("DataConvert"), DefaultValue("enter keywords here")]
[Editor("System.Windows.Forms.Design.StringCollectionEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(UITypeEditor))]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
public List<string> ReplaceItemsList
{
get
{
return _replaceItems;
}
set
{
_replaceItems = value;
}
}
public PropsClass()
{
TypeDescriptor.AddProvider(new CustumTypeDescriptorProvider(), typeof(List<string>));
}
public void SaveToIniFile(string filename)
{
// write to ini file
using (var fp = new StreamWriter(filename, false, Encoding.UTF8))
{
// for each different section
foreach (var section in GetType()
.GetProperties()
.GroupBy(x => ((CategoryAttribute)x.GetCustomAttributes(typeof(CategoryAttribute), false)
.FirstOrDefault())?.Category ?? "General"))
{
fp.WriteLine(Environment.NewLine + "[{0}]", section.Key);
foreach (var propertyInfo in section.OrderBy(x => x.Name))
{
var converter = TypeDescriptor.GetConverter(propertyInfo.PropertyType);
fp.WriteLine("{0}={1}", propertyInfo.Name, converter.ConvertToInvariantString(propertyInfo.GetValue(this, null)));
}
}
}
}
public void ReadFromIniFile(string filename)
{
// Load all sections from file
var loaded = GetType().GetProperties()
.Select(x => ((CategoryAttribute)x.GetCustomAttributes(typeof(CategoryAttribute), false).FirstOrDefault())?.Category ?? "General")
.Distinct()
.ToDictionary(section => section, section => GetKeys(filename, section));
//var loaded = GetKeys(filename, "General");
foreach (var propertyInfo in GetType().GetProperties())
{
var category = ((CategoryAttribute)propertyInfo.GetCustomAttributes(typeof(CategoryAttribute), false).FirstOrDefault())?.Category ?? "General";
var name = propertyInfo.Name;
if (loaded.ContainsKey(category) && loaded[category].ContainsKey(name) && !string.IsNullOrEmpty(loaded[category][name]))
{
var rawString = loaded[category][name];
var converter = TypeDescriptor.GetConverter(propertyInfo.PropertyType);
if (converter.IsValid(rawString))
{
propertyInfo.SetValue(this, converter.ConvertFromString(rawString), null);
}
}
}
}
// helper function
private Dictionary<string, string> GetKeys(string iniFile, string category)
{
var buffer = new byte[8 * 1024];
GetPrivateProfileSection(category, buffer, buffer.Length, iniFile);
var tmp = Encoding.UTF8.GetString(buffer).Trim('\0').Split('\0');
return tmp.Select(x => x.Split(new[] { '=' }, 2))
.Where(x => x.Length == 2)
.ToDictionary(x => x[0], x => x[1]);
}
}
public class CustumTypeDescriptorProvider : TypeDescriptionProvider
{
public override ICustomTypeDescriptor GetTypeDescriptor(System.Type objectType, object instance)
{
if (objectType.Name == "List`1") return new StringListDescriptor();
return base.GetTypeDescriptor(objectType, instance);
}
}
public class StringListDescriptor : CustomTypeDescriptor
{
public override TypeConverter GetConverter()
{
return new StringListConverter();
}
}
public class StringListConverter : TypeConverter
{
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
if (sourceType == typeof(string))
{
return true;
}
return base.CanConvertFrom(context, sourceType);
}
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
string s = value as string;
if (!string.IsNullOrEmpty(s))
{
return ((string)value).Split(',').ToList();
}
return base.ConvertFrom(context, culture, value);
}
public override object? ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
{
if (destinationType == typeof(string))
{
return string.Join(",", (List<string>)value);
}
return base.ConvertTo(context, culture, value, destinationType);
}
}
*NOTE: In my testing, the method ConvertFrom is called twice, once from converter.IsValid and once from propertyInfo.SetValue.
*NOTE2: You are using streamwriter to update the ini file. Since you are using GetPrivateProfileSection, it seems you should be using WritePrivateProfileSection to update the ini file.
*NOTE3: please consider the original comments in question about whether you should be using this method to read/write to an ini file. These methods have been around a long time. (https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getprivateprofilesection)
*NOTE4: A lot of this answer came from: Convert string to Array of string using TypeConverter
Leaving apart the PropertyGrid part which is just a way to put the info in a cartesian way on a Windows Form, the tricky part as I understand it, is to force a ini file (which is typically a 1:1 correlation between strings and strings) to house a collection of right hand side (rhs) values. Obviously, they cannot reside of a left hand side (lhs) of the ini line. You could, but then likely the choice of a ini file to persist your data is wrong at the roots.
So, why not avoiding to reinvent the wheel and go straight to custom parsing? This way you can also choose the separator to use (you may like to mimic windows, or apache setting files, etc).
Look at this implementation of one old code of mine. Grossly, it is an ini file telling my app which web exchange to contact for crypto trading. Before you get into a big headache with names: Monday is the name of the library holding the common code, and Friday is an app using Monday for trading online with a specific algo. Nothing important for the case being.
The ini file looks like this:
[Friday]
; if true the permutations will be only defined starting from the currency provided with index 0 in [Friday-Currencies]
MaxChainTransactions = 7
; if UseLastTradeValues is true, it will override UseConservativeBidAskValues
UseLastTradeValues = true
; if true the matrix values are (Ask+Bid)/2. This flag overrides UseConservativeBidAskValues but gets overridden by UseLastTradeValues
UseMidPriceValues = false
; if true the most conservative value between bid and ask will be used to calculate gains. Used only if UseLastTradeValues is false
UseConservativeBidAskValues = true
; if true, the solver will also solve with a matrix that will contain the best trade values from the available exchanges in parallel to other exchanges individually
MergeExchanges = false
; If true, Friday will issue one solution (if any) for each exchange, comprising one for the merged market if calculated.
DeliverOneSolutionPerExchange = true
; use values from the provided exchanges only
FridayExchanges = Bittrex| Binance | Kraken
; the minimum allowed gain remaining at the closure of the transaction chain to approve the full chain for ordering
MimimumAllowedGain = 1.05
; this is the target gain of a transaction. it is not used in case AllowPriceCorrectionBelowTargetGain is false
TargetGain = 1.09
; if true the prices in the transaction will be modified (increased towards the aggressive trade) of a factor equal to MaxPriceCorrectionFactor
AllowPriceCorrectionBelowTargetGain = true
; the frequency of each solution cycle (provided that the previous cycle has already completed and new data is arrived)
SolveEveryNSeconds = 15
Look at the line:
FridayExchanges = Bittrex| Binance | Kraken
it receives more than one exchange as a string separated by a pipe (|). You may choose other separators.
I suppose you parse the ini file with the support of some third party code. I used ini-parser (https://github.com/rickyah/ini-parser) that helped me a lot.
Parsing is done this way:
private static (int, string[]) ReadFridayExchanges()
{
string? configEntry = MondayConfiguration.MondaySettings["Friday"]["FridayExchanges"];
List<string> fridayExchanges = configEntry.ParseExchangeKey();
return (fridayExchanges.Count, fridayExchanges.ToArray());
}
Leave apart all the variables and names, the interesting one is MondaySettings. It is defined like this:
using IniParser;
using IniParser.Model;
/// <summary>
/// Holds the dictionary of Settings in IniData format.
/// </summary>
public static IniData MondaySettings { get; private set; }
and initialized like this:
[MemberNotNull(nameof(MondaySettings))]
private static void ReadSettingsFile(string settingsFile)
{
var iniParser = new FileIniDataParser();
MondaySettings = iniParser.ReadFile(settingsFile);
if (!DateTime.TryParse(MondaySettings["General"]["LastShutDown"], out _))
{
CorrectLastShutDownTime();
}
}
you find all nice calls in the ini-parser package to read and write the ini files automatically with almost one-liners.
When saving the file before closing and exiting:
private static bool SaveInternalSettings(string settingsFilename)
{
string settingsFile = Path.Combine(SettingsLocationFullPath, settingsFilename);
MondaySettings["General"]["LastShutDown"] = DateTime.UtcNow.ToString(CultureInfo.InvariantCulture);
File.Delete(settingsFile);
try
{
var parser = new FileIniDataParser();
parser.WriteFile(settingsFile, MondaySettings);
return true;
}
catch
{
return false;
}
}
Now the interesting part: parsing multiple rhs values within ini. My solution was to do it manually, which is also one of the fastest ways.
/// <summary>
/// Reading Settings.ini for multi value lines, this routine parses the right hand side
/// of each records to define the list of values coupling it with the required
/// exchanges. Returns an array of exchanges that may be contained in a complex key to
/// resolve the All case and the presence of the pipe symbol (|).
/// NOTE: it makes use of the indexes for markets, therefore those structures should be
/// ready before this call to the method.
/// </summary>
/// <param name="rhrMarket">
/// The original key as written in the .ini file.
/// </param>
/// <returns>
/// A list of strings representing all the exchanges in a single record of
/// InterestingMarkets section the settings. If only one is contained in the original
/// key, a single element is contained.
/// </returns>
public static List<string> ParseExchangeKey(this string rhrMarket)
{
List<string> answer = new();
if (string.Equals(rhrMarket, "all", StringComparison.OrdinalIgnoreCase))
{
// producing all known exchanges as answer
foreach (KeyValuePair<string, int> ex in Tags.Exchanges.ActiveExchanges)
{
if (ex.Value != 0) // to exclude Monday which is id=0
{
answer.Add(ex.Key);
}
}
}
else if (rhrMarket.Contains('|'))
{
// sorting multiple cases
string[] split = rhrMarket.Split('|');
foreach (string? subElement in split)
{
answer.Add(subElement.ToLower().Trim());
}
}
else
{
answer.Add(rhrMarket.ToLower());
}
return answer;
}
There is also some XML to help you get to the point. As you can see, ParseExchangeKey returns a list of strings.
Just to make sure you have all the elements to get the Ienumerables, this is the definition of Tags.Exchanges.ActiveExchanges:
/// <summary>
/// Contains the set of active exchanges included into [ActiveExchanges] section in
/// settings.ini and having proper credentials to activate the web account. The
/// Values of the dictionary are the ID in _allExchanges. Monday is not included.
/// </summary>
[PublicAPI]
public static Dictionary<string, int> ActiveExchanges => _b_activeExchanges_;
/// <summary>
/// IMPL: This is internal because it needs to be set by <see cref="MondayConfiguration"/>.
/// it does not contain Monday's entry.
/// </summary>
private static readonly Dictionary<string, int> _b_activeExchanges_ = LoadExchangesDictionary();
private static Dictionary<string, int> LoadExchangesDictionary()
{
Dictionary<string, int> answer = new();
// set it internally without using the property which blocks the caller up the
// closure of the dictionary.
var counter = 0;
foreach (KeyValuePair<string, int> item in _allExchanges_)
{
if (item.Value != 0 && MondayConfiguration.Credentials.Any(c => c.Exchange == item.Key))
{
answer.Add(item.Key.ToLower(), item.Value);
counter++;
}
}
Saving is the same, however ini-parser leaves the original string with separators (pipes in this case) in its memory, if your used modified the set of multi-values, you just need to provide a simple ToString() version to concatenate it back before saving the file using the accustomed separator.
Then coupling with the controls of the Windows Forms is easy when you can get the List<string> object to move around.
This way you may skip all the custom classes for converting the type around which will likely slow down maintenance when you need to add or remove records from the ini file.
I am using SharpSerializer to serialize/deserialize object.
I want the ability to ignore specific properties when deserializing.
SharpSerializer has an option to ignore properties by attribute or by classes and property name:
SharpSerializerSettings.AdvancedSettings.AttributesToIgnore
SharpSerializerSettings.AdvancedSettings.PropertiesToIgnore
but it seems that these settings are only used to ignore from serialization, not from deserialization (I tested with the GitHub source code and the NugetPackage).
Am I correct?
Is there any way to ignore attributes/properties from deserialization?
P.S.
I'm sure there are other great serialization libraries, but it will take a great amount of effort to change the code and all the existing serialized files.
I opened an issue on the GitHub project, but the project does not seem to be active since 2018.
The object with properties to ignore need not be the root object.
You are correct that SharpSerializer does not implement ignoring of property values when deserializing. This can be verified from the reference source for ObjectFactory.fillProperties(object obj, IEnumerable<Property> properties):
private void fillProperties(object obj, IEnumerable<Property> properties)
{
foreach (Property property in properties)
{
PropertyInfo propertyInfo = obj.GetType().GetProperty(property.Name);
if (propertyInfo == null) continue;
object value = CreateObject(property);
if (value == null) continue;
propertyInfo.SetValue(obj, value, _emptyObjectArray);
}
}
This code unconditionally sets any property read from the serialization stream into the incoming object using reflection, without checking the list of ignored attributes or properties.
Thus the only way to ignore your desired properties would seem to be to create your own versions of XmlPropertyDeserializer or BinaryPropertyDeserializer that skip or filter the unwanted properties. The following is one possible implementation for XML. This implementation reads the properties from XML into a Property hierarchy as usual, then applies a filter action to remove properties corresponding to .NET properties with a custom attribute [SharpSerializerIgnoreForDeserialize] applied, then finally creates the object tree using the pruned Property.
[System.AttributeUsage(System.AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
public class SharpSerializerIgnoreForDeserializeAttribute : System.Attribute { }
public class PropertyDeserializerDecorator : IPropertyDeserializer
{
readonly IPropertyDeserializer deserializer;
public PropertyDeserializerDecorator(IPropertyDeserializer deserializer) => this.deserializer = deserializer ?? throw new ArgumentNullException();
public virtual void Open(Stream stream) => deserializer.Open(stream);
public virtual Property Deserialize() => deserializer.Deserialize();
public virtual void Close() => deserializer.Close();
}
public class CustomPropertyDeserializer : PropertyDeserializerDecorator
{
Action<Property> deserializePropertyAction;
public CustomPropertyDeserializer(IPropertyDeserializer deserializer, Action<Property> deserializePropertyAction = default) : base(deserializer) => this.deserializePropertyAction = deserializePropertyAction;
public override Property Deserialize()
{
var property = base.Deserialize();
if (deserializePropertyAction != null)
property.WalkProperties(p => deserializePropertyAction(p));
return property;
}
}
public static partial class SharpSerializerExtensions
{
public static SharpSerializer Create(SharpSerializerXmlSettings settings, Action<Property> deserializePropertyAction = default)
{
// Adapted from https://github.com/polenter/SharpSerializer/blob/42f9a20b3934a7f2cece356cc8116a861cec0b91/SharpSerializer/SharpSerializer.cs#L139
// By https://github.com/polenter
var typeNameConverter = settings.AdvancedSettings.TypeNameConverter ??
new TypeNameConverter(
settings.IncludeAssemblyVersionInTypeName,
settings.IncludeCultureInTypeName,
settings.IncludePublicKeyTokenInTypeName);
// SimpleValueConverter
var simpleValueConverter = settings.AdvancedSettings.SimpleValueConverter ?? new SimpleValueConverter(settings.Culture, typeNameConverter);
// XmlWriterSettings
var xmlWriterSettings = new XmlWriterSettings
{
Encoding = settings.Encoding,
Indent = true,
OmitXmlDeclaration = true,
};
// XmlReaderSettings
var xmlReaderSettings = new XmlReaderSettings
{
IgnoreComments = true,
IgnoreWhitespace = true,
};
// Create Serializer and Deserializer
var reader = new DefaultXmlReader(typeNameConverter, simpleValueConverter, xmlReaderSettings);
var writer = new DefaultXmlWriter(typeNameConverter, simpleValueConverter, xmlWriterSettings);
var _serializer = new XmlPropertySerializer(writer);
var _deserializer = new CustomPropertyDeserializer(new XmlPropertyDeserializer(reader), deserializePropertyAction);
var serializer = new SharpSerializer(_serializer, _deserializer)
{
//InstanceCreator = settings.InstanceCreator ?? new DefaultInstanceCreator(), -- InstanceCreator not present in SharpSerializer 3.0.1
RootName = settings.AdvancedSettings.RootName,
};
serializer.PropertyProvider.PropertiesToIgnore = settings.AdvancedSettings.PropertiesToIgnore;
serializer.PropertyProvider.AttributesToIgnore = settings.AdvancedSettings.AttributesToIgnore;
return serializer;
}
public static void WalkProperties(this Property property, Action<Property> action)
{
if (action == null || property == null)
throw new ArgumentNullException();
// Avoid cyclic dependencies.
// Reference.IsProcessed is true only for the first reference of an object.
bool skipProperty = property is ReferenceTargetProperty refTarget
&& refTarget.Reference != null
&& !refTarget.Reference.IsProcessed;
if (skipProperty) return;
action(property);
switch (property.Art)
{
case PropertyArt.Collection:
{
foreach (var item in ((CollectionProperty)property).Items)
item.WalkProperties(action);
}
break;
case PropertyArt.Complex:
{
foreach (var item in ((ComplexProperty)property).Properties)
item.WalkProperties(action);
}
break;
case PropertyArt.Dictionary:
{
foreach (var item in ((DictionaryProperty)property).Items)
{
item.Key.WalkProperties(action);
item.Value.WalkProperties(action);
}
}
break;
case PropertyArt.MultiDimensionalArray:
{
foreach (var item in ((MultiDimensionalArrayProperty )property).Items)
item.Value.WalkProperties(action);
}
break;
case PropertyArt.Null:
case PropertyArt.Simple:
case PropertyArt.Reference:
break;
case PropertyArt.SingleDimensionalArray:
{
foreach (var item in ((SingleDimensionalArrayProperty)property).Items)
item.WalkProperties(action);
}
break;
default:
throw new NotImplementedException(property.Art.ToString());
}
}
public static void RemoveIgnoredChildProperties(Property p)
{
if (p.Art == PropertyArt.Complex)
{
var items = ((ComplexProperty)p).Properties;
for (int i = items.Count - 1; i >= 0; i--)
{
if (p.Type.GetProperty(items[i].Name)?.IsDefined(typeof(SharpSerializerIgnoreForDeserializeAttribute), true) == true)
{
items.RemoveAt(i);
}
}
}
}
}
Then, given the following models:
public class Root
{
public List<Model> Models { get; set; } = new ();
}
public class Model
{
public string Value { get; set; }
[SharpSerializerIgnoreForDeserialize]
public string IgnoreMe { get; set; }
}
You would deserialize using the customized XmlPropertyDeserializer as follows:
var settings = new SharpSerializerXmlSettings();
var customSerialzier = SharpSerializerExtensions.Create(settings, SharpSerializerExtensions.RemoveIgnoredChildProperties);
var deserialized = (Root)customSerialzier.Deserialize(stream);
If you need binary deserialization, use the following factory method to create the serializer instead:
public static partial class SharpSerializerExtensions
{
public static SharpSerializer Create(SharpSerializerBinarySettings settings, Action<Property> deserializePropertyAction = default)
{
// Adapted from https://github.com/polenter/SharpSerializer/blob/42f9a20b3934a7f2cece356cc8116a861cec0b91/SharpSerializer/SharpSerializer.cs#L168
// By https://github.com/polenter
var typeNameConverter = settings.AdvancedSettings.TypeNameConverter ??
new TypeNameConverter(
settings.IncludeAssemblyVersionInTypeName,
settings.IncludeCultureInTypeName,
settings.IncludePublicKeyTokenInTypeName);
// Create Serializer and Deserializer
Polenter.Serialization.Advanced.Binary.IBinaryReader reader;
Polenter.Serialization.Advanced.Binary.IBinaryWriter writer;
if (settings.Mode == BinarySerializationMode.Burst)
{
// Burst mode
writer = new BurstBinaryWriter(typeNameConverter, settings.Encoding);
reader = new BurstBinaryReader(typeNameConverter, settings.Encoding);
}
else
{
// Size optimized mode
writer = new SizeOptimizedBinaryWriter(typeNameConverter, settings.Encoding);
reader = new SizeOptimizedBinaryReader(typeNameConverter, settings.Encoding);
}
var _serializer = new BinaryPropertySerializer(writer);
var _deserializer = new CustomPropertyDeserializer(new BinaryPropertyDeserializer(reader), deserializePropertyAction);
var serializer = new SharpSerializer(_serializer, _deserializer)
{
//InstanceCreator = settings.InstanceCreator ?? new DefaultInstanceCreator(), -- InstanceCreator not present in SharpSerializer 3.0.1
RootName = settings.AdvancedSettings.RootName,
};
serializer.PropertyProvider.PropertiesToIgnore = settings.AdvancedSettings.PropertiesToIgnore;
serializer.PropertyProvider.AttributesToIgnore = settings.AdvancedSettings.AttributesToIgnore;
return serializer;
}
}
And do:
var settings = new SharpSerializerBinarySettings();
var customSerialzier = SharpSerializerExtensions.Create(settings, SharpSerializerExtensions.RemoveIgnoredChildProperties);
var deserialized = (Root)customSerialzier.Deserialize(stream);
Notes:
The methods SharpSerializerExtensions.Create() were modeled on SharpSerializer.initialize(SharpSerializerXmlSettings settings) and SharpSerializer.initialize(SharpSerializerBinarySettings settings) by Pawel Idzikowski
The version of SharpSerializer available on nuget, version 3.0.1, only includes commits through 10/8/2017. Submissions since then that add the ability to use Autofac as the instance creator are not available via nuget. My code is based on the version available via nuget, and thus does not initialize SharpSerializer.InstanceCreator which was added in 2018. The project appears not to have updated at all since then.
SharpSerializer.Deserialize() deserializes to the type specified in the serialization stream rather than to a type specified by the caller. It thus appears vulnerable to the sort of type injection attacks described in Alvaro Muñoz & Oleksandr Mirosh's blackhat paper https://www.blackhat.com/docs/us-17/thursday/us-17-Munoz-Friday-The-13th-JSON-Attacks-wp.pdf.
For details see e.g. TypeNameHandling caution in Newtonsoft Json.
If you are willing to fork, modify and build SharpSerializer yourself, you might consider updating ObjectFactory.fillProperties(object obj, IEnumerable<Property> properties) to not set ignored properties.
Demo fiddle #1 here for XML, and #2 here for binary.
So basically I have a custom UserControl containing a private array of Label objects and I want to be able to access exclusively their Text properties from the outside.
I therefore added a property which type LabelTextCollection is an implementation of IEnumerable and has my Label array as its inner list. Furthermore, I added an implementation of UITypeEditor to allow editing from the windows forms designer.
To try it out, I added my control in a form and edited the property's value. All of that works fine until I close and reopen the designer and the labels take back their default values.
After looking around it seems I have to add an implementation of CodeDomSerializer to allow my type to succesfully serialize into the {Form}.Designer.cs file at design time. I tried serializing a comment line first to test it out but no code is generated.
My final goal would be to have a line like
this.{controlName}.Titles.FromArray(new string[] { "Whatever" } )
added at design time after the property was modified using my editor.
What am I misunderstanding and/or doing wrong ?
Custom Type
[DesignerSerializer(typeof(LabelTextCollectionSerializer), typeof(CodeDomSerializer))]
public class LabelTextCollection : IEnumerable<string>, IEnumerable
{
private Label[] labels;
public LabelTextCollection(Label[] labels)
{
this.labels = labels;
}
public void SetLabels(Label[] labels)
{
this.labels = labels;
}
public IEnumerator<string> GetEnumerator()
{
return new LabelTextEnum(labels);
}
IEnumerator IEnumerable.GetEnumerator()
{
return new LabelTextEnum(labels);
}
public string this[int index]
{
get { return labels[index].Text; }
set { labels[index].Text = value; }
}
public override string ToString()
{
if (labels.Length == 0) return string.Empty;
else
{
StringBuilder sb = new StringBuilder("{ ");
foreach (string label in this)
{
sb.Append(label);
if (label == this.Last()) sb.Append(" }");
else sb.Append(", ");
}
return sb.ToString();
}
}
public string[] ToArray()
{
string[] arr = new string[labels.Length];
for (int i = 0; i < labels.Length; i++) arr[i] = labels[i].Text;
return arr;
}
public void FromArray(string[] arr)
{
for(int i = 0; i < arr.Length; i++)
{
if (i >= labels.Length) break;
else labels[i].Text = arr[i];
}
}
public class LabelTextEnum : IEnumerator<string>, IEnumerator
{
private readonly Label[] labels;
private int position = -1;
public LabelTextEnum(Label[] labels)
{
this.labels = labels;
}
public object Current
{
get
{
try
{
return labels[position].Text;
}
catch (IndexOutOfRangeException)
{
throw new InvalidOperationException();
}
}
}
string IEnumerator<string>.Current { get { return (string)Current; } }
public void Dispose()
{
return;
}
public bool MoveNext()
{
return ++position < labels.Length;
}
public void Reset()
{
position = -1;
}
}
}
Type Editor
public class LabelTextCollectionEditor : UITypeEditor
{
IWindowsFormsEditorService _service;
IComponentChangeService _changeService;
public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
if (provider != null)
{
_service = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
_changeService = (IComponentChangeService)provider.GetService(typeof(IComponentChangeService));
if (_service != null && _changeService != null && value is LabelTextCollection)
{
LabelTextCollection property = (LabelTextCollection)value;
LabelTextCollectionForm form = new LabelTextCollectionForm() { Items = property.ToArray() };
if (_service.ShowDialog(form) == DialogResult.OK)
{
property.FromArray(form.Items);
value = property;
_changeService.OnComponentChanged(value, null, null, null);
}
}
}
return value;
}
public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.Modal;
}
}
Serializer
public class LabelTextCollectionSerializer : CodeDomSerializer
{
public override object Serialize(IDesignerSerializationManager manager, object value)
{
var baseSerializer = (CodeDomSerializer)manager.GetSerializer( typeof(LabelTextCollection).BaseType, typeof(CodeDomSerializer));
object codeObject = baseSerializer.Serialize(manager, value);
if (codeObject is CodeStatementCollection && value is LabelTextCollection)
{
var col = value as LabelTextCollection;
var statements = (CodeStatementCollection)codeObject;
statements.Add(new CodeCommentStatement("LabelTextCollection : " + col.ToString()));
}
return codeObject;
}
}
Property of custom Type
[Category("Appearance")]
[Editor(typeof(LabelTextCollectionEditor), typeof(UITypeEditor))]
public LabelTextCollection Titles { get; }
EDIT :
I added a set to my Titles property and set up my project for design-time debugging, I then realized that an exception was thrown on the line
object codeObject = baseSerializer.Serialize(manager, value);
stating that the Label type isn't marked as [Serializable].
I'm assuming that the base serializer is trying to write a call to my LabelTextCollection constructor and to serialize the labels field as a parameter of it.
I tried replacing the line with
object codeObject = new CodeObject();
which got rid of the exception but didn't write anything in the designer.cs file.
I'm (once again) assuming that nothing is happening because there is no relation between the CodeObject I just created and the file (unless that relation is established after it's returned by the Serialize method ?).
As you can probably tell, I'm pretty new regarding the CodeDom stuff so how should I create this object properly ?
EDIT 2 :
I'm so dumb... I forgot the codeObject is CodeStatementCollection test...
So the comment line is writing fine, now all I need to do is to write the correct line with CodeDom and it should work fine.
If someone wants to help, I currently have added to the designer.cs file :
this.FromArray( new string[] { "TEST" } );
So I'm missing the control's and the property's names to get to my final goal.
I'll answer my own post to recapitulate what I did to fix it when that's done.
I managed to make the serialization work as I intended so I'm going to recap what I changed from the code I originally posted.
First my property of custom type needed a set to be able to be modified by the editor.
[Editor(typeof(LabelTextCollectionEditor), typeof(UITypeEditor))]
public LabelTextCollection Titles { get; set; }
I wrongly assumed that the property's value was changing because the label's texts were effectively changing in the designer after using the editor.
That was happening because the editor could access the reference to the inner label array through the use of the LabelTextCollection.FromArray method.
With the setter, the property is now properly edited at design-time.
The rest of the changes are all in the serializer so i'm posting the whole updated code :
public class LabelTextCollectionSerializer : CodeDomSerializer
{
public override object Serialize(IDesignerSerializationManager manager, object value)
{
CodeStatementCollection codeObject = new CodeStatementCollection();
if (value is LabelTextCollection)
{
LabelTextCollection col = value as LabelTextCollection;
// Building the new string[] {} statement with the labels' texts as parameters
CodeExpression[] strings = new CodeExpression[col.Count()];
for (int i = 0; i < col.Count(); i++) strings[i] = new CodePrimitiveExpression(col[i]);
CodeArrayCreateExpression arrayCreation = new CodeArrayCreateExpression(typeof(string[]), strings);
// Building the call to the FromArray method of the currently serializing LabelTextCollection instance
ExpressionContext context = manager.Context.Current as ExpressionContext;
CodeMethodInvokeExpression methodInvoke = new CodeMethodInvokeExpression(context.Expression, "FromArray", arrayCreation);
codeObject.Add(methodInvoke);
}
return codeObject;
}
}
To recap the changes I made in that class :
Removed the call to the baseSerializer.Serialize method to manage the whole serialization myself
Initializing the codeObject variable as a new CodeStatementCollection
Building my call to the LabelTextCollection.FromArray method using CodeDom
All of that now successfully writes the line I wanted in the Designer.cs file.
PS :
Thanks to #TnTinMn for the help and the push in the right direction.
EDIT :
After thorough testing of the serializer, I realized that the labels' texts went back to their default value when rebuilding the assembly containing the LabeltextCollection type while having a design view of a form containing my custom control opened.
The reason for that was that the property of LabeltextCollection type could not be serialized because the condition value is LabelTextCollection was false in that case as there was a discrepancy between two LabelTextCollection types from different assembly versions.
To fix that, I removed any direct reference to the type and accessed the method I needed to call through the Type class.
That got me the following serializer code :
public class LabelTextCollectionSerializer : CodeDomSerializer
{
public override object Serialize(IDesignerSerializationManager manager, object value)
{
CodeStatementCollection codeObject = new CodeStatementCollection();
// Building the new string[] {} statement with the labels' texts as parameters
string[] texts = value.GetType().GetMethod("ToArray").Invoke(value, null) as string[];
CodeExpression[] strings = new CodeExpression[texts.Length];
for (int i = 0; i < texts.Length; i++) strings[i] = new CodePrimitiveExpression(texts[i]);
CodeArrayCreateExpression arrayCreation = new CodeArrayCreateExpression(typeof(string[]), strings);
// Building the call to the FromArray method of the currently serializing LabelTextCollection instance
ExpressionContext context = manager.Context.Current as ExpressionContext;
CodeMethodInvokeExpression methodInvoke = new CodeMethodInvokeExpression(context.Expression, "FromArray", arrayCreation);
codeObject.Add(methodInvoke);
return codeObject;
}
}
You could still test the type of value using Type.Name but as my serializer only manages a single type, that wasn't needed in my case.
I have a problem and can't wrap my mind around it:
I made a mathode which should set propertie values of an specific attribute "MappingAttribute" and return the new object.
The problem:
The attribute values are always set to the default value "false".
Where am I wrong?
static public T MapToClass<T>(SqlDataReader reader) where T : class
{
T returnedObject = Activator.CreateInstance<T>();
PropertyInfo[] modelProperties = returnedObject.GetType().GetProperties();
for (int i = 0; i < modelProperties.Length; i++)
{
MappingAttribute[] attributes = modelProperties[i].GetCustomAttributes<MappingAttribute>(true).ToArray();
if (attributes.Length > 0) {
attributes[0].AutoIncrement = true;
attributes[0].Primekey = true;
}
}
return returnedObject;
}
Attributes are not stored anywhere except in the assembly metadata. They are only materialized into attribute instances when asked to do so by reflection - in your case via GetCustomAttributes<MappingAttribute>. But: you then discard these. The next time GetCustomAttributes<MappingAttribute> is called, fresh new instances will be handed out, with the values from the assembly metadata.
Basically: updating properties of attribute instances does not mean that other code will see those changes when that code asks about attribute metadata.
To illustrate this:
using System;
class FooAttribute : Attribute { public string Value { get; set; } }
[Foo(Value = "abc")]
class Bar
{
static void Main()
{
var attrib = (FooAttribute)typeof(Bar)
.GetCustomAttributes(typeof(FooAttribute), false)[0];
Console.WriteLine(attrib.Value); // "abc"
attrib.Value = "def";
Console.WriteLine(attrib.Value); // "def"
// now re-fetch
attrib = (FooAttribute)typeof(Bar)
.GetCustomAttributes(typeof(FooAttribute), false)[0];
Console.WriteLine(attrib.Value); // "abc"
}
}
I know that the same problem is faced by a lot of people in one way or another but what I'm confused about is that how come Newtonsoft JSON Serializer is able to correctly handle this case while JavaScriptSerializer fails to do so.
I'm going to use the same code sample used in one of the other stackoverflow thread (JavascriptSerializer serializing property twice when "new" used in subclass)
void Main()
{
System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
var json = serializer.Serialize(new Limited());
Limited status = serializer.Deserialize<Limited>(json); --> throws AmbiguousMatchException
}
public class Full
{
public String Stuff { get { return "Common things"; } }
public FullStatus Status { get; set; }
public Full(bool includestatus)
{
if(includestatus)
Status = new FullStatus();
}
}
public class Limited : Full
{
public new LimitedStatus Status { get; set; }
public Limited() : base(false)
{
Status = new LimitedStatus();
}
}
public class FullStatus
{
public String Text { get { return "Loads and loads and loads of things"; } }
}
public class LimitedStatus
{
public String Text { get { return "A few things"; } }
}
But if I use Newtonsoft Json Serializer, everythings works fine. Why? And is it possible to achieve the same using JavaScriptSerializer?
void Main()
{
var json = JsonConvert.SerializeObject(new Limited());
Limited status = JsonConvert.DeserializeObject<Limited>(json); ----> Works fine.
}
The reason this works in Json.NET is that it has specific code to handle this situation. From JsonPropertyCollection.cs:
/// <summary>
/// Adds a <see cref="JsonProperty"/> object.
/// </summary>
/// <param name="property">The property to add to the collection.</param>
public void AddProperty(JsonProperty property)
{
if (Contains(property.PropertyName))
{
// don't overwrite existing property with ignored property
if (property.Ignored)
return;
JsonProperty existingProperty = this[property.PropertyName];
bool duplicateProperty = true;
if (existingProperty.Ignored)
{
// remove ignored property so it can be replaced in collection
Remove(existingProperty);
duplicateProperty = false;
}
else
{
if (property.DeclaringType != null && existingProperty.DeclaringType != null)
{
if (property.DeclaringType.IsSubclassOf(existingProperty.DeclaringType))
{
// current property is on a derived class and hides the existing
Remove(existingProperty);
duplicateProperty = false;
}
if (existingProperty.DeclaringType.IsSubclassOf(property.DeclaringType))
{
// current property is hidden by the existing so don't add it
return;
}
}
}
if (duplicateProperty)
throw new JsonSerializationException("A member with the name '{0}' already exists on '{1}'. Use the JsonPropertyAttribute to specify another name.".FormatWith(CultureInfo.InvariantCulture, property.PropertyName, _type));
}
Add(property);
}
As you can see above, there is specific code here to prefer derived class properties over base class properties of the same name and visibility.
JavaScriptSerializer has no such logic. It simply calls Type.GetProperty(string, flags)
PropertyInfo propInfo = serverType.GetProperty(memberName,
BindingFlags.Instance | BindingFlags.IgnoreCase | BindingFlags.Public);
This method is documented to throw an exception in exactly this situation:
Situations in which AmbiguousMatchException occurs include the following:
A type contains two indexed properties that have the same name but different numbers of parameters. To resolve the ambiguity, use an overload of the GetProperty method that specifies parameter types.
A derived type declares a property that hides an inherited property with the same name, using the new modifier (Shadows in Visual Basic). To resolve the ambiguity, include BindingFlags.DeclaredOnly to restrict the search to members that are not inherited.
I don't know why Microsoft didn't add logic for this to JavaScriptSerializer. It's really a very simple piece of code; perhaps it got eclipsed by DataContractJsonSerializer?
You do have a workaround, which is to write a custom JavaScriptConverter:
public class LimitedConverter : JavaScriptConverter
{
const string StuffName = "Stuff";
const string StatusName = "Status";
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
var limited = new Limited();
object value;
if (dictionary.TryGetValue(StuffName, out value))
{
// limited.Stuff = serializer.ConvertToType<string>(value); // Actually it's get only.
}
if (dictionary.TryGetValue(StatusName, out value))
{
limited.Status = serializer.ConvertToType<LimitedStatus>(value);
}
return limited;
}
public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
{
var limited = (Limited)obj;
if (limited == null)
return null;
var dict = new Dictionary<string, object>();
if (limited.Stuff != null)
dict.Add(StuffName, limited.Stuff);
if (limited.Status != null)
dict.Add(StatusName, limited.Status);
return dict;
}
public override IEnumerable<Type> SupportedTypes
{
get { return new [] { typeof(Limited) } ; }
}
}
And then use it like:
try
{
System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
serializer.RegisterConverters(new JavaScriptConverter[] { new LimitedConverter() });
var json = serializer.Serialize(new Limited());
Debug.WriteLine(json);
var status = serializer.Deserialize<Limited>(json);
var json2 = serializer.Serialize(status);
Debug.WriteLine(json2);
}
catch (Exception ex)
{
Debug.Assert(false, ex.ToString()); // NO ASSERT.
}