.net miner

In one of my previously published article (very old 🙂 one), I mentioned briefly about reflection, and discuss how reflection is an important concept in .Net Framework. While it is a very important concept there is a performance issue related with the Reflection. If you over use reflection codes in your projects you have to face with performance issues compared with the code that is implemented in this sample project.

In that context, I have explained two methods to have a better performance when manipulating objects dynamically and I have shared code examples about them. As a summary, I created a ObjectCreateMethod class which uses DynamicMethods and creates an IL which calls type constructors. By calling that generated DynamicMethod we can create instance of types faster than traditional reflection. If you are interested in and need more information, you can access article from here.

After reviewing previous article, now you are ready to get more information about the usage of the DynamicMethods that improve the performance of traditional reflection which is the subject of this article.

In the previous article, maybe you have discerned an imperfection. The ObjectCreateMetod class – which uses DynamicMethods for creating instance of a type – is only suitable for creating instance of types which has parameter-less constructors.

While I was surfing the web, I found a feedback about my article. Someone asks if it is possible to use ObjectCreateMethod class with types which has parameterized constructors. Because of this, I decided to updated my code, and now it also supports the constructors with parameter(s).

To resolve this issue I created a dynamic method which takes object[] argument as the constructor arguments. Than I take these parameters on to the stack and call new opcode. Here is the code;

/// <summary>
///  Creates the dynamic proxy method which calls given <see cref="ConstructorInfo"/>
/// </summary>
/// <param name="methodInfo"></param>
private static DynamicMethodDelegate CreateProxyMethod(ConstructorInfo constructor)
{
    var method = new DynamicMethod(constructor.DeclaringType.Name + "_ctor_Proxy",
        typeof(object),
        new Type[] { typeof(object[]) },
        constructor.DeclaringType);

    var wrapper = new ILGeneratorWrapper(method.GetILGenerator());

    var parameters = constructor.GetParameters();
    var parameterTypes = new Type[parameters.Length + 1];
    parameterTypes[0] = constructor.DeclaringType;
    for (int i = 0; i < parameters.Length; i++)
    {
        parameterTypes[i + 1] = parameters[i].ParameterType;
    }

    wrapper.DeclareLocals(parameterTypes);

    for (int i = 1; i < parameterTypes.Length; i++)
    {
        wrapper.EmitLoadArg(0);
        wrapper.EmitLoadCons(i - 1);
        wrapper.Emit(OpCodes.Ldelem_Ref);
        wrapper.EmitCast(parameterTypes[i]);
        wrapper.EmitStoreLocal(i);
    }

    for (int i = 1; i < parameterTypes.Length; i++)
    {
        wrapper.EmitLoadLoc(i);
    }

    wrapper.Emit_NewObj(constructor);

    wrapper.EmitStoreLocal(0);
    wrapper.EmitLoadLoc(0);
    wrapper.Emit(OpCodes.Ret);

    return method.CreateDelegate(typeof(DynamicMethodDelegate)) as DynamicMethodDelegate;
}

I also added some other helper proxy classes which provides invoking other type members (fields, properties and methods) by using DynamicMethods too.

RichTextBox is a control which provides formatting features that TextBox control does not provide. For instance, you can customize the text’s color, style and/or size. So, you can apply formatting to a word, a line or all of the paragraph. RichTextBox is useful if you want to have more control over styling, but although it supports search in its content by the “Find” functionality, it does not have a search UI, so this reduces control’s user-friendly design. If you need to search something in RichTextBox you should add new code blocks, functions, UI controls.

With the following code blocks, we derived a searchable RichTextBox control from RichTextBox which provides search(Find) functionality with a “Find” pop-up. Searchable RichTextBox does not assist any UI customization nevertheless it allows using ‘Control + F’ function in the text content. For more, review the following blocks.

An example screenshot of the Searchable RichTextBox Control

You can get full source code from my git-hup page. Here is the link.

If you are developing a setup project with visual studio which contains custom action in it, you might have problems with the OLE calls (for ex: Copy to clipboard or paste from clipboard) and showing a dialog (for ex: FolderBrowser, OpenFileDialog, SaveFileDialog etc.). This is simply because of the thread structure of the setup projects.

MSI projects does not expect that your custom actions needs OLE  calls. Therefore they are not calling your custom actions with a thread which is apartment state is STA. If you want to make OLE calls, your thread must be in STA apartment state. Therefore if you show a form in your custom action and try to call Clipboard.SetData or Clipboard.GetData in your form, then you get a STA-MTA thread exception. Also your setup project will be locked when you try to show a dialog form in your custom action form.

Download Source Code From GitHub | Watch Sample Movie(v1.0.5.0)

 What is Process Viewer?

I can say that Process Viewer is a program like Microsoft Spy++. Unlikely to Spy++ it allows you to edit some properties of the Controls and also allows you to manage its window messages. You can change Text, Visibility, Enabled, Window Styles and Window Ex Styles properties of a control by using PV during run time. There withal you can ignore window messages, change incoming message to a different message or edit parameters of any window messages by putting breakpoints to the control’s window procedure with PV.

An example screenshot of the Process Viewer

An example screenshot of the Flags Editor

PropertyGrid will use default editor for the properties which’s type is enum. This default editor does not allow multiple selections even the Enum has Flags attribute.

I have been prepared a new Editor for this kind of properties.

Our editor’s code is as follows;

internal class FlagsEditor : UITypeEditor
{
   FlagsEditorControl editor = null;
   public FlagsEditor()
   { }
    
   // our editor is a Drop-down editor
   public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
   {
      return UITypeEditorEditStyle.DropDown;
   } 
  
   public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
   {
       // if value is not an enum than we can not edit it
      if  (!(value is Enum))
         throw new Exception("Value doesn't support");
     
      // try to figure out that is this a Flags enum or not ?
      Type enumType = value.GetType();
      object[] attributes =  enumType.GetCustomAttributes(typeof(FlagsAttribute), true);
      if (attributes.Length == 0)
         throw new Exception("Editing enum hasn't got Flags attribute");
      // check the underlying type
      Type type = Enum.GetUnderlyingType(value.GetType());
      if (type != typeof(byte) && type != typeof(sbyte)  && 
            type != typeof(short) && type != typeof(ushort) && 
           type != typeof(int)&& type != typeof(uint))
        return value;
      if (provider != null)
      {
         // use windows forms editor service to show drop down
         IWindowsFormsEditorService edSvc = provider.GetService( 
              typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
         if (edSvc == null)
             return value;
         if (editor == null)
             editor = new FlagsEditorControl(this);
         // prepare list
         editor.Begin(edSvc, value);
         // show drop down now
         edSvc.DropDownControl(editor);
         // now we take the result
         value = editor.Value;
         // reset editor
         editor.End();
      }
      return Convert.ChangeType(value, type);
   }
}

In this code FlagsEditorControl is a UserControl which PropertyGrid hosts it in a drop down during the edit operation.
You can change your design by changing this Control.

To use this editor for a property, we have to write Editor Attribute to that property as the below;

// set editor of this property to our FlagsEditor
[Editor(typeof(FlagsEditor), typeof(UITypeEditor))]
public FileAttributes FlagsAttribute
{
       get { return _FlagsAttribute; }
       set { _FlagsAttribute = value; }
}

EnableWindow function enables or disables the mouse and keyboard input to the specified control. You can use this function from user32.dll as the follows;

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern bool EnableWindow(HandleRef hWnd, bool enable);
  
[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern bool EnableWindow(IntPtr hWnd, boolenable);

Today I wrote a simple example which shows how we can use CollectionEditor of the .NET. In addition to this I also made a simple example which shows how to implement custom CollectionEditor which allows us to add more than one item to the collection.

An example screenshot of the Collection Editor

An example screenshot of the Custom Property Grid Tab

Most of the programmers who uses Visual Studio .NET knows PropertyGrid which is the main control in the Properties Window of the Visual Studio.

If you have written any .NET components you must be familiar with Category and Description attributes. We use Category attribute to identify the property’s category and Description attribute is for the short description of that property. But because of the nature of Attributes in .NET we cannot pass any parameter to these attributes for Multilanguage support.

[Category(Properties.Resources.MyCategory)]
[Description(Properties.Resources.MyDescription)]
public int MyProperty { … }

This kind of usage is not allowed for .NET, because we are only allowed to give constant values to the attributes constructor.  So how can we use these attributes as Multilanguage?

If you are using Team Foundation Server with Visual Studio, it will be useful for you to integrate your projects bug system with the TFS Work Items system. You can write a simple module for your program which will handles the exceptions and collects needed information and send them to the TFS.

So how can we do something like that? First you have to write an error management module which will handles exceptions, errors, etc. and generates understandable information from them. After generating this information lastly you have to send this information to the TFS.