Develop Reference

Hosting Windows Forms Designer - Serialize designer at runtime and generate C# code

I am creating a designer surface and loading the controls to a runtime.
I am having issues when deserializing/loading the controls to the runtime.
All methods I have tried seem to have some type of issue.
Issued faced for example:
Controls are still bound of the design-time
Not all properties deserialize with all the properties, namely nested properties.
Control associations does seem to be followed, i.e. Button in a Panel, will not be in the panel anymore, even though the property is still the parent after loading.
I have created a sample Project on git here: Surface Designer Test
There are the main code snippets:
Serialization from the design-time
private void LoadRuntime(int type)
{
var controls = surface.ComponentContainer.Components;
SerializationStore data = (SerializationStore)surface.
_designerSerializationService.Serialize(controls);
MemoryStream ms = new MemoryStream();
data.Save(ms);
SaveData.Data = ms.ToArray();
SaveData.LoadType = type;
new RuntimeForm().Show();
}
public object Serialize(System.Collections.ICollection objects)
{
ComponentSerializationService componentSerializationService =
_serviceProvider.GetService(typeof(ComponentSerializationService)) as
ComponentSerializationService;
SerializationStore returnObject = null;
using (SerializationStore serializationStore =
componentSerializationService.CreateStore())
{
foreach (object obj in objects)
{
if (obj is Control control)
{
componentSerializationService.SerializeAbsolute(serializationStore, obj);
}
returnObject = serializationStore;
}
}
return returnObject;
}
Deserialization in runtime
Here is attempt with reflection:
MemoryStream ms = new MemoryStream(SaveData.Data);
Designer d = new Designer();
var controls = d._designerSerializationService.Deserialize(ms);
ms.Close();
if (SaveData.LoadType == 1)
{
foreach (Control cont in controls)
{
var ts = Assembly.Load(cont.GetType().Assembly.FullName);
var o = ts.GetType(cont.GetType().FullName);
Control controlform = (Control)Activator.CreateInstance(o);
PropertyInfo[] controlProperties = cont.GetType().GetProperties();
foreach (PropertyInfo propInfo in controlProperties)
{
if (propInfo.CanWrite)
{
if (propInfo.Name != "Site" && propInfo.Name != WindowTarget")
{
try
{
var obj = propInfo.GetValue(cont, null);
propInfo.SetValue(controlform, obj, null);
}
catch { }
}
else { }
}
}
Controls.Add(controlform);
}
}
Here is attempt with loading controls directly (still bound to the design-time):
MemoryStream ms = new MemoryStream(SaveData.Data);
Designer d = new Designer();
var controls = d._designerSerializationService.Deserialize(ms);
foreach (Control cont in controls)
Controls.Add(cont);
I feel like I am missing a concept from the System.ComponentModel.Design framework.
I also do not believe there is a need to write a custom serializer for each control, as surely the already have this has Visual Studio is able to serialize all their properties as they are changed in the PropertyGrid and load them back when you run the program.
I'd love to serialize the designer into a .cs file, but how? How do you serialize controls/form and changed properties to a file like the VS designer, I tried and looked only to find xml and binary serializer. My ideal solution would be build a designer.cs with the CodeDom.
What is the correct way do accomplish this serialization between design-time and run-time?

Assuming you have a DesignSurface to show a Form as root component of the designer and having some components created at run-time by using CreateComponent method of IDesignerHost, here is how I approach the problem:
Get an instance of IDesignerHost from DesignSurface
Create new DesignerSerializationManager
Get an instance of TypeCodeDomSerializer from serialization manager
Serialize the RootComponent of the IDesignerHost
Create an instance of CSharpCodeProvider
Generate code by calling GenerateCodeFromType and passing the serialized root component.
You can also extend the example a bit and use ISelectionService to get notified about selected components and change properties at run-time using a PropertyGrid:
Example - Generate C# code from DesignSurface at runtime
Here in this example, I'll show how you can host a windows forms designer at run-time and design a form containing some controls and components and generate C# code at run-time and run the generated code.
Please note: It's not a production code and it's just an example as a
proof of concept.
Create the DesignSurface and host the designer
You can create the design surface like this:
DesignSurface designSurface;
private void Form1_Load(object sender, EventArgs e)
{
designSurface = new DesignSurface(typeof(Form));
var host = (IDesignerHost)designSurface.GetService(typeof(IDesignerHost));
var root = (Form)host.RootComponent;
TypeDescriptor.GetProperties(root)["Name"].SetValue(root, "Form1");
root.Text = "Form1";
var button1 = (Button)host.CreateComponent(typeof(Button), "button1");
button1.Text = "button1";
button1.Location = new Point(8, 8);
root.Controls.Add(button1);
var timer1 = (Timer)host.CreateComponent(typeof(Timer), "timer1");
timer1.Interval = 2000;
var view = (Control)designSurface.View;
view.Dock = DockStyle.Fill;
view.BackColor = Color.White;
this.Controls.Add(view);
}
Generate C# code using TypeCodeDomSerializer and CSharpCodeProvider
This is how I generate code from design surface:
string GenerateCSFromDesigner(DesignSurface designSurface)
{
CodeTypeDeclaration type;
var host = (IDesignerHost)designSurface.GetService(typeof(IDesignerHost));
var root = host.RootComponent;
var manager = new DesignerSerializationManager(host);
using (manager.CreateSession())
{
var serializer = (TypeCodeDomSerializer)manager.GetSerializer(root.GetType(),
typeof(TypeCodeDomSerializer));
type = serializer.Serialize(manager, root, host.Container.Components);
type.IsPartial = true;
type.Members.OfType<CodeConstructor>()
.FirstOrDefault().Attributes = MemberAttributes.Public;
}
var builder = new StringBuilder();
CodeGeneratorOptions option = new CodeGeneratorOptions();
option.BracingStyle = "C";
option.BlankLinesBetweenMembers = false;
using (var writer = new StringWriter(builder, CultureInfo.InvariantCulture))
{
using (var codeDomProvider = new CSharpCodeProvider())
{
codeDomProvider.GenerateCodeFromType(type, writer, option);
}
return builder.ToString();
}
}
For example:
var code = GenerateCSFromDesigner(designSurface);
Run the code sing CSharpCodeProvider
Then to run it:
void Run(string code, string formName)
{
var csc = new CSharpCodeProvider();
var parameters = new CompilerParameters(new[] {
"mscorlib.dll",
"System.Windows.Forms.dll",
"System.dll",
"System.Drawing.dll",
"System.Core.dll",
"Microsoft.CSharp.dll"});
parameters.GenerateExecutable = true;
code = $#"
{code}
public class Program
{{
[System.STAThread]
static void Main()
{{
System.Windows.Forms.Application.EnableVisualStyles();
System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);
System.Windows.Forms.Application.Run(new {formName}());
}}
}}";
var results = csc.CompileAssemblyFromSource(parameters, code);
if (!results.Errors.HasErrors)
{
System.Diagnostics.Process.Start(results.CompiledAssembly.CodeBase);
}
else
{
var errors = string.Join(Environment.NewLine,
results.Errors.Cast<CompilerError>().Select(x => x.ErrorText));
MessageBox.Show(errors);
}
}
For example:
Run(GenerateCSFromDesigner(designSurface), "Form1");

Caliburn Micro - View & viewmodel in separate DLL

I've been trying this for a while and i have some issues. I have a project which dynamically loads 1 or more DLLs and I can't get the view binding to work.
I've overridden the SelectAssemblies method as such:
protected override IEnumerable<Assembly> SelectAssemblies()
{
string[] AppFolders = Directory.GetDirectories(Config.AppsFolder);
List<Assembly> assemblies = new List<Assembly>();
assemblies.Add(Assembly.GetExecutingAssembly());
foreach (string f in AppFolders)
{
Assembly ass = Directory.GetFiles(f, "*.dll", SearchOption.AllDirectories).Select(Assembly.LoadFrom).SingleOrDefault();
if (ass != null)
{
assemblies.Add(ass);
}
}
Apps = assemblies;
return assemblies;
}
This works as intended, i then have a method which runs on a button click which does:
public void OpenApp(string appName)
{
//AppName should be the same as the dll.
string assName = string.Format("TabletApp.{0}", appName);
Assembly ass = AppBootstrapper.Apps.SingleOrDefault(x => x.GetAssemblyName() == assName);
if (ass != null)
{
dynamic vm = ass.CreateInstance(string.Format("TabletApp.{0}.ViewModels.{0}ViewModel", appName));
IoC.Get<IWindowManager>().ShowDialog(vm);
}
}
This finds the viewmodel fine, however i get the error "unable to find contract for 'ExampleView'" when i load ExampleViewModel. I've also had to add [Export(typeof(view)] for each view in the base assembly since I've made this changes. It appears that Caliburn micro has stopped initialising views automatically.
Anyone know what i've done wrong?

So it turns out i was doing nothing wrong, Along the way I've updated my caliburn.micro to 3.0.2. As it turns out a small change they made became a major breaking update. I wont go into it fully here other than to point out its the GetInstance in the bootstrapper that needs to be changed.
protected override object GetInstance(Type service, string key)
{
// Skip trying to instantiate views since MEF will throw an exception
if (typeof(UIElement).IsAssignableFrom(service))
return null;
var contract = string.IsNullOrEmpty(key) ? AttributedModelServices.GetContractName(service) : key;
var exports = container.GetExportedValues<object>(contract);
if (exports.Any())
return exports.First();
throw new Exception(string.Format("Could not locate any instances of contract {0}.", contract));
}
Please review the following link for more detailed information.
https://github.com/Caliburn-Micro/Caliburn.Micro/pull/339

How to get the value of a property of a class in a non executing assembly through reflection

I'm having trouble while getting the value of the text property in a non-executing assembly; I read an assembly from disk via reflection, then i get all classes in the assembly to search for the Text property in a windows form class which is initialized by win forms designer. So far i have the following code:
static void Main(string[] args)
{
Assembly asm = Assembly.LoadFrom(Path.Combine(path, "Assembly.exe"));
PropertyInfo[] props;
foreach (Type t in asm.GetTypes())
{
var value = t.GetProperty("Text").GetValue(/*Not sure what to put here*/)
}
}
And this is how the designer generated the form
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None
Me.BackColor = System.Drawing.Color.FromArgb(CType(CType(0, Byte), Integer), CType(CType(128, Byte), Integer), CType(CType(128, Byte), Integer))
Me.ClientSize = New System.Drawing.Size(234, 181)
Me.Cursor = System.Windows.Forms.Cursors.Default
Me.Font = New System.Drawing.Font("Arial", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
Me.ForeColor = System.Drawing.SystemColors.WindowText
Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog
Me.Location = New System.Drawing.Point(581, 222)
Me.MaximizeBox = False
Me.MinimizeBox = False
Me.Name = "winform"
Me.RightToLeft = System.Windows.Forms.RightToLeft.No
Me.StartPosition = System.Windows.Forms.FormStartPosition.Manual
Me.Text = "Title"
Me.fraDías.ResumeLayout(False)
Me.ResumeLayout(False)
Keep in mind that the assembly is on disk and non-executing and that I want to retrieve the value of the Text property of every winform (I guess it should be somewhere hardcoded in the assembly since it was generated by the winforms designer)
Please tell me if this is possible, thanks!

Your requirements are contradictory, when you load an aseembly via reflection, and instantiate an object or try to get a property value, what happens is that some code begins to run, there is no way around that.
Remember that properties are just "syntax sugar" for a pair of methods, the getter and setter. Their current value is nothing but the value returned by the getter method, and when you change its value, you're in fact calling its setter method. So, to retrieve property values, you must make some code to run, even if it's a trivial get method.
I think maybe your confusion comes from the fact that you're using a designer to create the form. Particularly with the WinForms designer (WPF for instance is substantially different), all it does is to autogenerate some code for you. Setting properties, placing and moving controls around, what's happening under the hood is that it writes code that replicate your actions at runtime, specifically, it codes the InitializeComponent method. The real property value is set when the constructor is called (that in turn calls InitializeComponent), and then you may read/change using many properties.
What you would need to read those designer attributes is that those were hardcoded in some form of metadata, so that it's simply read as data and not as the result of code execution. That's not the case with WinForms, as it "saves" the form as code.

You cannot read a property of a class that has not been instantiated! The parameter you are missing is an instance of your type.
You must create an instance of the type with object o = Activator.CreateInstance(type); before accessing its members (unless they are static).
Your problem is related to how add-ins (plug-ins) can be loaded at runtime.
Here is how I made an Add-In Loader. Below, I will explain how you can adapt it to your problem. Add-Ins have to implement the IAddIn interface in my example. You are totally free in the definition of IAddIn. You could define it like this:
public interface IAddIn
{
bool OnLoad();
string Version { get; set; }
string Text { get; set; }
}
This allows you to access members without reflection.
public class AddInLoader
{
// Loads all non abstract types implementing IAddIn in all DLLs found in a folder.
public IList<IAddIn> Load(string folder)
{
var addIns = new List<IAddIn>();
string[] files = Directory.GetFiles(folder, "*.dll");
foreach (string file in files) {
addIns.AddRange(LoadFromAssembly(file));
}
return addIns;
}
// Loads all non abstract types implementing IAddIn found in a file.
private static IEnumerable<IAddIn> LoadFromAssembly(string fileName)
{
Assembly asm = Assembly.LoadFrom(fileName);
string addInInterfaceName = typeof(IAddIn).FullName;
foreach (Type type in asm.GetExportedTypes()) {
Type interfaceType = type.GetInterface(addInInterfaceName);
if (interfaceType != null &&
(type.Attributes & TypeAttributes.Abstract) != TypeAttributes.Abstract){
IAddIn addIn = (IAddIn)Activator.CreateInstance(type);
addIn.Version = asm.GetName().Version.ToString();
yield return addIn;
}
}
}
}
Now you can load and access the add-ins like this:
var loader = new AddInLoader();
IList<IAddIn> addIns = loader.Load(folderPath);
foreach (IAddIn addIn in addIns) {
if (addIn.OnLoad()) {
Console.WriteLine("Version = {0}, Text = {1}", addIn.Version, addIn.Text);
}
}
Reading the titles of Forms at runtime:
You can easily adapt this example. Instead of searching for types implementing an interface, search for types deriving from System.Windows.Forms.Form.
private static IEnumerable<Form> LoadFormsFromAssembly(string fileName)
{
Assembly asm = Assembly.LoadFrom(fileName);
foreach (Type type in asm.GetExportedTypes()) {
if (typeof(Form).IsAssignableFrom(type) &&
(type.Attributes & TypeAttributes.Abstract) != TypeAttributes.Abstract) {
Form form = (Form)Activator.CreateInstance(type);
yield return form;
}
}
}
Now you can get the texts of the forms like this:
var forms = LoadFormsFromAssembly(path);
foreach (Form frm in forms) {
Console.WriteLine(frm.Text);
}
Note: You must instantiate the forms, however you do not need to open (show) them. The code works only if the forms have a default constructor, i.e. a constructor without parameters.

You need an instance object for that type to get the value of a property.
It looks like you just want to check if a type has a "Text" property or not. You can to it by checking
bool hasTextProperty = t.GetProperty("Text") !=null;

Is it possible to execute C# code represented as string?

On my form I have a button click
private void button1_Click(object sender, EventArgs e)
{
do something
}
How on the click would I load my do something from a text file, for example my text file looks like this:
MessageBox.Show("hello");
label1.Text = "Hello";
on click it does everything in my text file, if possible.

Here is a very simple example, just to prove this is possible. Basically, you use CodeDomProvider to compile source at runtime, then execute using reflection.
var provider = CodeDomProvider.CreateProvider("C#");
string src=#"
namespace x
{
using System;
public class y
{
public void z()
{
Console.WriteLine(""hello world"");
}
}
}
";
var result = provider.CompileAssemblyFromSource(new CompilerParameters(), src);
if (result.Errors.Count == 0)
{
var type = result.CompiledAssembly.GetType("x.y");
var instance = Activator.CreateInstance(type);
type.GetMethod("z").Invoke(instance, null);
}
Edit
As #Agat points out, the OP seems to require a sort of scripting framework (it makes use of label1, a property of the current object), whereas my answer above obviously does not provide that. The best I can think of is a limited solution, which would be to require dependencies to be specified explicitly as parameters in the "script". Eg, write the scripted code like this:
string src = #"
namespace x
{
using System.Windows;
public class y
{
public void z(Label label1)
{
MessageBox.Show(""hello"");
label1.Text = ""Hello"";
}
}
}
";
Now you can have the caller examine the parameters, and pass them in from the current context, again using reflection:
var result = provider.CompileAssemblyFromSource(new CompilerParameters(), src);
if (result.Errors.Count == 0)
{
var type = result.CompiledAssembly.GetType("x.y");
var instance = Activator.CreateInstance(type);
var method = type.GetMethod("z");
var args = new List<object>();
// assume any parameters are properties/fields of the current object
foreach (var p in method.GetParameters())
{
var prop = this.GetType().GetProperty(p.Name);
var field = this.GetType().GetField(p.Name);
if (prop != null)
args.Add(prop.GetValue(this, null));
else if (field != null);
args.Add(field.GetValue(this));
else
throw new InvalidOperationException("Parameter " + p.Name + " is not found");
}
method.Invoke(instance, args.ToArray());
}

Like the other answers have stated, it isn't an easy thing to implement and can possibly be done through reflection depending on how advanced your scripts are.
But no one #BrankoDimitrijevic mentioned Roslyn and it is a great tool. http://msdn.microsoft.com/en-us/vstudio/roslyn.aspx
It hasn't been updated in quite awhile (Sept.2012) and doesn't have all of the features of C# implemented, however, it did have a lot of it implemented when I played around with this release.
By adding your assembly as a reference to the scripting session, you're able to gain access to all of your assembly's types and script against them. It also supports return values so you can return any data that a scripted method generates.
You can find what isn't implemented here.
Below is a quick and dirty example of Roslyn that I just wrote and tested. Should work right out of box after installing Roslyn from NuGet. The small bloat at the initialization of the script engine can easily be wrapped up in a helper class or method.
The key is passing in a HostObject. It can be anything. Once you do, your script will have full access to the properties. Notice that you just call the properties and not the host object in the script.
Basically, your host object will contain properties of the data you need for your script. Don't necessarily think of your host object as just a single data object, but rather a configuration.
public class MyHostObject
{
public string Value1 { get; set; }
public string Value2 { get; set; }
}
public class RoslynTest
{
public void Test()
{
var myHostObject = new MyHostObject
{
Value1 = "Testing Value 1",
Value2 = "This is Value 2"
};
var engine = new ScriptEngine();
var session = engine.CreateSession(myHostObject);
session.AddReference(myHostObject.GetType().Assembly.Location);
session.AddReference("System");
session.AddReference("System.Core");
session.ImportNamespace("System");
// "Execute" our method so we can call it.
session.Execute("public string UpdateHostObject() { Value1 = \"V1\"; Value2 = \"V2\"; return Value1 + Value2;}");
var s = session.Execute<string>("UpdateHostObject()");
//s will return "V1V2" and your instance of myHostObject was also changed.
}
}

No. You can not.
At least in any simple way.
The thing you want is something like eval('do something') from javascript.
That's not possible to do with C#. C# is a language which needs compilation before execution unlike javascript (for instance).
The only way to implement that is to build your own (pretty complicated as for beginner) parser and execute it in such way.
UPDATED:
Actually, as JDB fairly noticed, that's really not the only way. I love programming! There are so many ways to make a freakky (or even sometimes that really can be necessary for some custom interesting tasks (or even learning)!) code. he he
Another approach I've got in my mind is building some .cs file, then compiling it on-the-fly and working with it as some assembly or some other module. Right.

Custom workflow activity errors 'Value cannot be null'

I'm creating a custom workflow activity in VS2010 targeting .NET 3.5. The DLL is actually being used in a Microsoft System Center Service Manager custom workflow, but I don't think that is my issue.
I have a public string property, that the user types in the string of what the activity should use. However, when the WF runs, it errors out 'value cannot be null'. I want to target if it is my code or something else.
When we drag my custom activity onto the designer, I'm able to type in the text of the string on the designer for that property.
public static DependencyProperty ChangeRequestStageProperty = DependencyProperty.Register("ChangeRequestStage", typeof(String), typeof(UpdateChangeRequestStage));
[DescriptionAttribute("The value to set the ChangeRequestStage Property in the ChangeRequest Extension class.")]
[CategoryAttribute("Change Request Extension")]
[BrowsableAttribute(true)]
[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Visible)]
public String Stage
{
get { return ((String)(base.GetValue(UpdateChangeRequestStage.ChangeRequestStageProperty))); }
set { base.SetValue(UpdateChangeRequestStage.ChangeRequestStageProperty, value); }
}
protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
{
EnterpriseManagementGroup emg = CreateEMG();
//System.WorkItem.ChangeRequest Extension - ClassExtension_928bec0a_cac4_4a0a_bd89_7146c9052fbe
ManagementPackClass mpcChangeRequest = emg.EntityTypes.GetClass(new Guid("8c6c6057-56ad-3862-47ec-dc0dde80a071"));
//System.WorkItemContainsActivity Relationship Class
ManagementPackRelationship workItemContainsActivityRelationship = emg.EntityTypes.GetRelationshipClass(new Guid("2DA498BE-0485-B2B2-D520-6EBD1698E61B"));
EnterpriseManagementObject changeRequest = null;
//Loop thru each emo (Change Request in this case), and assign it. There will never be more than 1 emo returned
foreach (EnterpriseManagementObject obj in emg.EntityObjects.GetRelatedObjects<EnterpriseManagementObject>(executionContext.ContextGuid, workItemContainsActivityRelationship, TraversalDepth.OneLevel, ObjectQueryOptions.Default))
{ changeRequest = obj; }
EnterpriseManagementObjectProjection emop = new EnterpriseManagementObjectProjection(changeRequest);
if (emop != null)
{ emop.Object[mpcChangeRequest, "ChangeRequestStage"].Value = Stage; }
emop.Commit();
return base.Execute(executionContext);
}
Since it is getting a 'value cannot be null' error, I'm guessing it's on this line:
emop.Object[mpcChangeRequest, "ChangeRequestStage"].Value = Stage;
I'm going to test and see if hardcoding a value works or not. Any ideas?
enter code here

try this
if (emop != null && emop.Object[mpcChangeRequest, "ChangeRequestStage"] != null)
emop.Object[mpcChangeRequest, "ChangeRequestStage"].Value = Stage

I didn't want to leave this question wide open, so I'm updating it as to how I resolved this (a long time ago).
Rather than working with an EnterpriseManagementObjectProjection (emop), I worked with a standard EnterpriseManagementObject (emo). From there, I was able to follow a similar format from above:
ManagementPackClass mpcChangeRequest = emg.EntityTypes.GetClass(new Guid("8c246fc5-4e5e-0605-dc23-91f7a362615b"));
changeRequest[mpcChangeRequest, "ChangeRequestStage"].Value = this.Stage;
changeRequest.Commit();