radtextbox, detecting paste

[superold]

Hi.

How can I detect the paste drop down event? I need to message the user when the pasting text does not fit the filtering mask. I tried with 0x0302 in WndProc but without success.

- jorge

[Boyko Markov]

Hello Jorge Delgado-Lopez,

I have prepared a way to detect WM_PASTE message in RadTextBox. Here is the solution:

1. Declare  WM_PASTE const:
     private const int WM_PASTE = 0x0302;
2. Create a class called MessageIntercept:

   public class MessageIntercept : NativeWindow, IDisposable
        {
            #region Fields

            private Control targetControl;

            private MessageHandler messageHandlerCallback;

            #endregion

            #region Constructor

            /// <summary>
            /// Creates an instance of the MessageInterceptor class.
            /// </summary>
            /// <param name="target">The target Control which messages to intercept</param>
            /// <param name="messageCallback">A reference to a method that is invoked when a message is received.</param>
            public MessageIntercept(Control target, MessageHandler messageCallback)
            {
                this.targetControl = target;
                this.messageHandlerCallback = messageCallback;
                this.targetControl.HandleCreated += new EventHandler(targetControl_HandleCreated);
                this.targetControl.HandleDestroyed += new EventHandler(targetControl_HandleDestroyed);

                if (this.targetControl.IsHandleCreated)
                {
                    this.AssignHandle(this.targetControl.Handle);
                }
            }





            #endregion

            #region Properties

            /// <summary>
            /// Gets the target control associated with the MessageInterceptor.
            /// </summary>
            public Control Target
            {
                get
                {
                    return this.targetControl;
                }
            }

            public bool IsActive
            {
                get
                {
                    return this.targetControl.IsHandleCreated;
                }
            }

            #endregion

            #region Methods

            public void SetMessageReceivedCallback(MessageHandler callback)
            {
                this.messageHandlerCallback = callback;
            }

            protected override void WndProc(ref Message m)
            {
                base.WndProc(ref m);

                if (this.messageHandlerCallback != null)
                {
                    this.messageHandlerCallback(ref m);
                }
            }

            #endregion

            #region Event handling

            private void targetControl_HandleCreated(object sender, EventArgs e)
            {
                this.AssignHandle(this.targetControl.Handle);
            }


            private void targetControl_HandleDestroyed(object sender, EventArgs e)
            {
                this.ReleaseHandle();

            }
            #endregion

            #region IDisposable Members

            public void Dispose()
            {
                if (this.targetControl != null)
                {
                    this.messageHandlerCallback = null;
                    this.ReleaseHandle();
                }
            }

            #endregion
        }

3. After doing that, you should create an instance of that class:

        MessageIntercept handler = new MessageIntercept(this.radTextBox1.TextBoxElement.TextBoxItem.HostedControl, MessageInterceptor);
    
4. We passed the MessageInterceptor callback method as a parameter. Now it is time to declare it:

public void MessageInterceptor(ref Message msg)
        {
            if (msg.Msg == WM_PASTE)
            {
         // TO DO
            }
        }

This will handle the WM_PASTE message. Another solution that will handle the Paste through the CTRL+V shortcut could be to subscribe to the KeyDown event

1.    this.radTextBox1.TextBoxElement.TextBoxItem.HostedControl.KeyDown += new KeyEventHandler(HostedControl_KeyDown);

2,  In the event handler, you can check whether CTRL + V is pressed

 void HostedControl_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Modifiers == Keys.Control && e.KeyCode == Keys.V)
            {
            
               // TO DO
            }
        }

Please write me back if you need more information.

Regards,
Boyko Markov
the Telerik team

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[jerry]

Boyko,
How can this be done for a textbox column within a grid?  If I have max length set at 10 and they past a 15 character string 5 characters are chopped off and the user will not know.  I want to be able to let them know that some of their text has been truncated.  Any help would be greatly appreciated.

Thank You

[Svett]

Hello jerry,

Yes, you can use the code snippet that my colleague Boyko gave you. You should subscribe to CellBeginEdit and CellEndEdit events of the grid where you can register and unregister to the events or messages of the text box editor.

You can use the following code snippet that is based on Boyko's sample:

void radGridView_CellBeginEdit(object sender, GridViewCellCancelEventArgs e)
{
    RadTextBoxEditor textBoxEditor = this.radGridView.ActiveEditor as RadTextBoxEditor;
    RadTextBoxEditorElement element = textBoxEditor.EditorElement as RadTextBoxEditorElement;
    Control hostedControl = element.HostedControl;
    hostedControl.KeyDown += new KeyEventHandler(hostedControl_KeyDown);
}

void radGridView_CellEndEdit(object sender, GridViewCellEventArgs e)
{
    RadTextBoxEditor textBoxEditor = this.radGridView.ActiveEditor as RadTextBoxEditor;
    RadTextBoxEditorElement element = textBoxEditor.EditorElement as RadTextBoxEditorElement;
    Control hostedControl = element.HostedControl;
    hostedControl.KeyDown -= new KeyEventHandler(hostedControl_KeyDown);
}

void hostedControl_KeyDown(object sender, KeyEventArgs e)
{
    if (e.Modifiers == Keys.Control && e.KeyCode == Keys.V)
    {

        // TO DO
    }
}

Another option is to use Boyko's first approach with MessageIntercept class. Hence, instead of subscribing and unsubscribing for KeyDown event, you should create and dispose the instance of MessageIntercept class that hooks this behavior.

If you need further assistance, feel free to write us back.

Regards,
Svett
the Telerik team

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