PropertyInfo.GetValue on Boolean is always True, how to handle False responses - c#

Similar to PropertyInfo.GetValue on Boolean is always True although no useful answer was posted.
I'm using Entity Framework to gather objects from a database and I'm trying to create Json structures as strings. However when gathering boolean answers in the same way as other types, the boolean always returns true.
I've tried to cast the value to a boolean here but I originally tried using the same method as other types (just using value). Is there a reason for this or a fix? Thanks
private static void AppendObjectPropertiesInJson(StringBuilder content, Object obj)
{
content.Append(" {\n");
foreach (PropertyInfo propertyInfo in obj.GetType().GetProperties())
{
var type = Nullable.GetUnderlyingType(propertyInfo.PropertyType) ?? propertyInfo.PropertyType;
var name = propertyInfo.Name;
var value = propertyInfo.GetValue(obj, null);
if (value == null)
content.Append(" \"" + name + "\": null,\n");
// Error, always returns true
else if (type == typeof(bool))
{
value = (bool)value;
content.Append(" \"" + name + "\": " + value.ToString().ToLower() + ",\n");
}
else if (type == typeof(int))
content.Append(" \"" + name + "\": " + value.ToString().ToLower() + ",\n");
else if (type == typeof(string))
content.Append(" \"" + name + "\": " + "\"" + value.ToString() + "\",\n");
// TODO: Handle arrays
}
content.Append(" },\n");
}
edit: Issue was with unexpected changes in database. Thanks to everybody who helped show there was no issue with this code

The premise of the question is incorrect; PropertyInfo.GetValue works just fine - here used with your method with zero changes:
static void Main()
{
var obj = new Foo { Bar = true, Blap = false };
var sb = new StringBuilder();
AppendObjectPropertiesInJson(sb, obj);
Console.WriteLine(sb);
}
class Foo
{
public bool Bar { get; set; }
public bool Blap { get; set; }
}
outputs the almost-JSON:
{
"Bar": true,
"Blap": false,
},
Note that the expression value = (bool)value is a redundant unbox+box, but: it doesn't change any results (just: it doesn't do anything useful, either).
Note that we can show native bool here too:
else if (type == typeof(bool))
{
var typed = (bool)value;
Console.WriteLine(typed ? "it was true" : "it was false");
// ...content.Append(" \"" + name + "\": " + value.ToString().ToLower() + ",\n");
}
If you have an example where PropertyInfo.GetValue doesn't work, then post that example. Additionally, note that writing your own JSON output is not recommended, as is very easy to get wrong.

Related

Extract only the values from SharePoint list with C#

I'm trying to extract the values of a SharePoint list to use with Revit to update the status parameters of some elements and after many tries I can connect and get the values if I know the keys for the dictionary inside every ListItem, but there are many problems with this approach.
The first one is the need to know the keys, sometimes the key is changed because of encoding, It would be more productive for me to get all the list values at one time. I tried to use a GetDataTable like some tutorials, but it appears that this don't work with the client.
The second is sometimes I can't get the value of the List but a description of the value, like "Microsoft.SharePoint.Client.FieldLookupValue".
Can someone help me with this issue? Bellow is the code I'm using.
using Microsoft.SharePoint.Client;
using System;
using System.Security;
namespace ConsoleTESTES
{
class Program
{
static void Main(string[] args)
{
string username = "USERNAME";
string siteURL = "SITEURL";
SecureString password = GetPassword();
GetAllWebProperties(siteURL, username, password);
}
public static void GetAllWebProperties(string siteURL, string username, SecureString password)
{
using (var context = new ClientContext(siteURL))
{
context.Credentials = new SharePointOnlineCredentials(username, password);
Web web = context.Web;
context.Load(web);
context.ExecuteQuery();
Console.WriteLine("Title: " + web.Title + "; URL: " + web.Url);
// Assume the web has a list named "Announcements".
//List lista = context.Web.Lists.GetByTitle("Lista teste");
List lista = context.Web.Lists.GetByTitle("LIST");
// This creates a CamlQuery that has a RowLimit of 100, and also specifies Scope="RecursiveAll"
// so that it grabs all list items, regardless of the folder they are in.
CamlQuery query = CamlQuery.CreateAllItemsQuery();
ListItemCollection items = lista.GetItems(query);
// Retrieve all items in the ListItemCollection from List.GetItems(Query).
context.Load(items);
context.ExecuteQuery();
//GET VALUES FROM LISTITEM
foreach (ListItem listItem in items)
{
Console.WriteLine(listItem["Setor"] + " " + "|" + " "
+ listItem["LocalServico"] + " " + "|" + " "
+ listItem["Equipe"] + " " + "|" + " "
+ listItem["Confeccao"]);
}
Console.ReadLine();
}
}
public static SecureString GetPassword()
{
ConsoleKeyInfo info;
SecureString securePassword = new SecureString();
do
{
info = Console.ReadKey();
if (info.Key != ConsoleKey.Enter)
{
securePassword.AppendChar(info.KeyChar);
}
}
while (info.Key != ConsoleKey.Enter);
return securePassword;
}
}
}
You could get the values from the fields collection, but be warned that some special types of fields might require special treatment for the values and that you might not need to get all the values from the server (you can probably reduce your payload):
var items = lista.GetItems(query);
var fields = list.Fields;
var fieldsToIgnore = new[] { "ContentType", "Attachments" };
context.Load(items);
context.Load(fields);
context.ExecuteQuery();
foreach (ListItem listItem in items)
{
foreach (Field field in fields)
{
if (!fieldsToIgnore.Contains(fld.InternalName))
Console.WriteLine(item[field.InternalName]);
}
}
There are some fields that might not be loaded by default of that you might not need, so I have included the fieldsToIgnore to make your test easier.
After some search I found this solution to my FieldLookUpTable, to avoid errors if the item is null I added a if statement, but I could access the value with (listItem["Setor"] as FieldLookupValue).LookupValue. Here my messy code to check if is a LookupValue and get the value. Now I need to implement Pedro's solution to get all the values without the need to write everyone.
String setor = "";
String localServico = "";
String confeccao = "";
if (listItem["Setor"] != null && listItem["Setor"].ToString() == "Microsoft.SharePoint.Client.FieldLookupValue")
{
setor = (listItem["Setor"] as FieldLookupValue).LookupValue;
}
else if (listItem["Setor"] != null && listItem["Setor"].ToString() != "Microsoft.SharePoint.Client.FieldLookupValue")
{
setor = listItem["Setor"].ToString();
}
if (listItem["LocalServico"] != null && listItem["LocalServico"].ToString() == "Microsoft.SharePoint.Client.FieldLookupValue")
{
localServico = (listItem["LocalServico"] as FieldLookupValue).LookupValue;
}
else if (listItem["LocalServico"] != null && listItem["LocalServico"].ToString() != "Microsoft.SharePoint.Client.FieldLookupValue")
{
localServico = listItem["LocalServico"].ToString();
}
if (listItem["Confeccao"] != null && listItem["Confeccao"].ToString() == "Microsoft.SharePoint.Client.FieldLookupValue")
{
confeccao = (listItem["Confeccao"] as FieldLookupValue).LookupValue;
}
else if (listItem["Confeccao"] != null && listItem["Confeccao"].ToString() != "Microsoft.SharePoint.Client.FieldLookupValue")
{
confeccao = listItem["Confeccao"].ToString();
}
Console.WriteLine(setor + " " + "|" + " "
+ localServico + " " + "|" + " "
+ confeccao);

Can Anyone help me retrieve data from parse using unity please?

I have managed to store data, but I can't retrieve it and i would be so grateful if someone could just help me get at least 1 example working.
First I am storing data when the user signs up:
public void SetupNewParseMember(ParseUser user)
{
ParseObject gameScore = new ParseObject("GameScore");
gameScore["cash"] = 500;
gameScore["playerName"] = user.Username;
gameScore["HighestCash"] = 500;
gameScore["GamesPlayed"] = 0;
Task saveTask = gameScore.SaveAsync();
}
This works fine, I can see the data in parse and all seems ok..
The problem is when i try to retrieve the objects.
public void SetupMainScreen(ParseUser user)
{
var query = ParseObject.GetQuery("GameScore").WhereEqualTo("playerName", user.Username);
query.FindAsync().ContinueWith(t =>
{
IEnumerable<ParseObject> results = t.Result;
List<ParseObject> resultsList = results.ToList();
DealWithResults(resultsList, user);
});
}
public void DealWithResults(List<ParseObject> resultsList, ParseUser me)
{
userGamesPlayed = resultsList[1].Get<int>("GamesPlayed");
userHighestCash = resultsList[2].Get<int>("HighestCash");
userCash = resultsList[3].Get<int>("Cash");
WelcomeText.text = "Welcome, " + me.Username + "\n" +
"Cash: $" + userCash + "\n" +
"Highest Cash: $" + userHighestCash + "\n" +
"Games Played: " + userGamesPlayed;
}
First I tried just making changes to the unity ui from inside the Query but that did not work, So i made an outside function and passed the results to it that way, and that still does not work?
I tried to debug what i was getting in the list with this:
foreach (var res in resultsList)
{
Debug.Log("Class Name = " + res.ClassName + "| Keys are: " + res.Keys);
}
But all it returned was:
Class Name = GameScore| Keys are: System.Collections.Generic.Dictionary`2+KeyCollection[System.String,System.Object]
Can anyone offer any insights?
EDIT2:
ok so first i found results list and its contents
http://i.imgur.com/IKcBbey.png
Then if i open it, it seems to be null ref?
http://i.imgur.com/VmSpi9c.png
But if i go digging, i found the info i need all the way down here
http://i.imgur.com/1Wwu5uc.png
Now just need to work out how to get it?
As there is only one set of data it is always accessible through resultsList[0]. What you want is:
double cash = (double)resultsList[0]["cash"];
string playerName = (string)resultsList[0]["playerName"];
double highestCash = (double)resultsList[0]["HighestCash"];
int gamesPlayed = (int)resultsList[0]["GamesPlayed"];
Though you probably want to check that resultsList is not null and contains one element before you try to dereference it.
Also as your ParseObject appears to be a Dictionary you might find this MSDN page useful.
Ended up solving it.. Much different to the examples...
I had to make a coroutine that called a function on callback to access the variables outside of the query.
I called it with
StartCoroutine(SetupMainScreen(me, DealWithResults));
then called this.
public IEnumerator SetupMainScreen(ParseUser user, Action<GameScore> callback)
{
var query = ParseObject.GetQuery("GameScore").WhereEqualTo("playerName", user.Username).FirstOrDefaultAsync();
while (!query.IsCompleted)
{
yield return null;
}
if (query.IsFaulted || query.IsCanceled)
{
Debug.Log("Getting of GameScores faulted or cancelled...");
}
else
{
var obj = query.Result;
if (obj != null)
callback(new GameScore(obj.Get<int>("cash"),obj.Get<string>("playerName"),obj.Get<int>("HighestCash"),obj.Get<int>("GamesPlayed")));
}
}
public void DealWithResults(GameScore gs)
{
WelcomeText.text = "Welcome, " + gs.Username + "\n" +
"Cash: $" + gs.Cash + "\n" +
"Highest Cash: $" + gs.HighestCash + "\n" +
"Games Played: " + gs.GamesPlayed;
}
And i just made a class to hold the objects.. Hopefully this helps someone else.

How to loop through properties of objects in c#?

I have a method which gets the values of the properties of an object and appends some commas to it. I want to make this generinc so i can use it with other objects.
foreach (var row in rows.ToList())
{
sbResult.Append(
delimiter + row.MediaName + delimiter + separator +
delimiter + row.CountryName + delimiter + separator +
delimiter + row.ItemOverRideDate + delimiter + separator +
delimiter + row.Rating + delimiter + separator +
delimiter + row.BatchNo + delimiter + separator +
delimiter + row.NoInBatch + delimiter + separator +
delimiter + row.BatchDate + delimiter + separator +
delimiter + row.DataType + delimiter + separator +
delimiter + row.ByLine + delimiter + separator +
delimiter + row.IssueNo + delimiter + separator +
delimiter + row.Issue + delimiter + separator +
delimiter + row.MessageNo + delimiter + separator +
delimiter + row.Message + delimiter + separator +
delimiter + row.SourceName + delimiter + separator +
delimiter + row.SourceType + delimiter + separator);
//end of each row
sbResult.AppendLine();
}
I have tried using var rowData = row.GetType().GetProperties(); but it only returns the property itself and I dont know how to get the value of the property.
Since Type.GetProperties returns a collection of PropertyInfo, you follow that up by calling PropertyInfo.GetValue. Here's how you can do that (and all the rest together) with LINQ:
var line = string.Join(
row.GetType().GetProperties()
.Select(pi => pi.GetValue(row))
.Select(v => delimiter + v.ToString() + delimiter),
separator);
However, you might want to reconsider your approach. This code will break if GetProperties fetches static properties or indexers along with "normal" properties; it also requires that the code be run with full trust (otherwise no reflection is possible). And finally, it's going to be slow because a) reflection is inherently slow and b) it will keep reflecting on the same things over and over again without caching any of the information it has already discovered.
In addition to the above potential problems, if there is even a remote chance that you will later want to filter what gets printed out it is probably better to encapsulate this logic inside a (virtual?) method on row and just do something like
sbResult.AppendLine(row.SerializeAsLine());
You can use something like this to iterate over all the properties of a particular type:
public static IEnumerable<KeyValuePair<string, T>> PropertiesOfType<T>(object obj)
{
return from p in obj.GetType().GetProperties()
where p.PropertyType == typeof(T)
select new KeyValuePair<string, T>(p.Name, (T)p.GetValue(obj));
}
Then you could specify the type as string for all your string properties.
Compilable sample:
using System;
using System.Collections.Generic;
using System.Linq;
namespace ConsoleApplication1
{
class Program
{
private static void Main()
{
var test = new Test
{
Str1 = "S1",
Str2 = "S2",
Str3 = "S3",
Str4 = "S4"
};
foreach (var property in PropertiesOfType<string>(test))
{
Console.WriteLine(property.Key + ": " + property.Value);
}
}
public static IEnumerable<KeyValuePair<string, T>> PropertiesOfType<T>(object obj)
{
return from p in obj.GetType().GetProperties()
where p.PropertyType == typeof(T)
select new KeyValuePair<string, T>(p.Name, (T)p.GetValue(obj));
}
}
public class Test
{
public string Str1 { get; set; }
public string Str2 { get; set; }
public string Str3 { get; set; }
public string Str4 { get; set; }
}
}
Here it is.
List<PropertyInfo> _propInfo = _row.GetType().GetProperties();
foreach (var item in _propInfo)
{
object _value = item.GetValue(_row, null);
if (_value != null)
{
// Save the Value
}
}
GetProperties returns an array of PropertyInfo, so use the GetValue method and use your object as it's input to get the value for each property. Here is the code:
public class MyClass
{
public string MyProperty1 { get; set; }
public string MyProperty2 { get; set; }
public string MyProperty3 { get; set; }
}
Then
MyClass myObj = new MyClass() { MyProperty1 = "first", MyProperty2 = "second", MyProperty3 = "third" };
List<string> array = new List<string>();
foreach (var item in typeof(MyClass).GetProperties())
{
array.Add(item.GetValue(myObj, null).ToString());
}
var result = string.Join(",", array); //use your own delimiter
var values = instance
.GetType()
.GetProperties(BindingFlags.Instance | BindingFlags.Public)
.Select(z => string.Format("{0}: {1}\n", z.Name, z.GetValue(instance, null)));
string res = string.Concat(values);
Where instance is the instance of your object. You might want to avoid LINQ and use a loop if StringBuilder is required (depending on the number of properties).

C# - Value cannot be null. Parameter name: type

when i try to run the code below, I am getting
"Value cannot be null. Parameter name: type"
error at runtime.
How to handle this exception and why my objectName is null here? I am expecting objectName to hold the value of local user account on my computer.
namespace Users
{
class EnableDisableUsers
{
public static void Main(string[] args)
{
Console.WriteLine("Enter user account to be enabled or disabled");
var user = Console.ReadLine();
Console.WriteLine("Enter E to enable and D to disable the user account");
string enableStr = Console.ReadLine();
bool enable;
var computer = ".";
if (enableStr.Equals("E") || enableStr.Equals("e"))
{
enable = true;
var objectName = "WinNT://" + computer + "/" + user + ",user";
dynamic objUser = Activator.CreateInstance(Type.GetTypeFromProgID(objectName));
objUser.AccountDisabled = false;
objUser.SetInfo();
Console.WriteLine(user + " Enabled = " + result.ToString());
Console.ReadLine();
}
else if (enableStr.Equals("D") || enableStr.Equals("d"))
{
enable = false;
var objectName = "WinNT://" + computer + "/" + user + ",user";
dynamic objUser = Activator.CreateInstance(Type.GetTypeFromProgID(objectName));
objUser.AccountDisabled = true;
objUser.SetInfo();
Console.WriteLine(user + " Enabled = " + result.ToString());
Console.ReadLine();
}
else
{
Console.WriteLine("Operation for " + user + " failed ");
}
}
}
}
Any help will be useful.
How to handle this exception and why my objectName is null here?
objectName is not going to be null. The more likely scenario is that Type.GetTypeFromProgID(objectName) is returning null, because that prog-id doesn't exist, or the account doesn't have access.
Check what Type.GetTypeFromProgID(objectName) returns, and act accordingly. Make sure it is actually a prog-id, and that you are using that API correctly. For example:
var type = Type.GetTypeFromProgID(objectName);
if(type == null) throw new InvalidOperationException(
"Invalid prog-id: " + objectName);
dynamic objUser = Activator.CreateInstance(type);
Edit: Note that Activator.CreateInstance etc is not the same as VBScript's GetObject. To access that, reference Microsoft.VisualBasic.dll, and use:
dynamic obj = Microsoft.VisualBasic.Interaction.GetObject(objectName);

Silverlight Reflection | GetCurrentMethod with passed parameters

I want to print the current method call (incl. return value) to the Visual Studio Output like this:
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
Func<object, object> ret = (value) =>
{
#if DEBUG
var debug = new StringBuilder();
debug.Append("MyConverter.Convert([");
debug.Append(values.Sum(v => (v != null ? v.ToString() : "null") + ',', null, v => v != null ? v.ToString() : "null"));
debug.Append("], " + targetType.ToString() + ", " + parameter.ToString() + ", " + culture.DisplayName + ") =" + value.ToString() + ";");
Debug.WriteLine(debug.ToString());
#endif
return value;
};
// [..]
}
I'm using this sometimes to achieve more informations (e.g. from a Converter as shown here) while debugging. However, that's just a roundabout way.
Is there any way to do it more flexible? Something like GetCurrentArguments (from MethodInfo)?
Since you are using it for debugging there is an option using the StackTrace and StackFrame To get the current method name, but you wont get the arguments, and there is a severe performance penalty.

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