CODEWITHSUNDEEP
c#winformsdrag-and-droprichtextbox
M. Page
M. Page

Reputation: 2814

C# Drag and Drop text within a RichTextBox

I have a C# project in which I want the user to be able to drag and drop text (i.e. to move text) within a RichTextBox in a WinForm.

I have found many examples showing how to do drop something onto a RichTextBox but I didn't succeed to have them work when the RichTextBox is both the drag source and drop target.

How should I do this ?

Below is my non-working attempt sofar.

public partial class Form1 : Form {
    public Form1() {
        InitializeComponent();
        this.richTextBox1.AllowDrop = true;
        this.richTextBox1.DragEnter += new System.Windows.Forms.DragEventHandler(this.richTextBox1_DragEnter);
        this.richTextBox1.DragDrop += new System.Windows.Forms.DragEventHandler(this.richTextBox1_DragDrop);
    }

    private void richTextBox1_DragEnter(object sender, System.Windows.Forms.DragEventArgs e) {
        if (e.Data.GetDataPresent(DataFormats.Rtf))
            e.Effect = DragDropEffects.Move;
        else
            e.Effect = DragDropEffects.None;
    }
    private void richTextBox1_DragDrop(object sender, System.Windows.Forms.DragEventArgs e) {
        int i;
        String s;

        i = richTextBox1.SelectionStart;
        s = richTextBox1.Text.Substring(i);
        richTextBox1.Text = richTextBox1.Text.Substring(0, i);

        richTextBox1.Text = richTextBox1.Text +
           e.Data.GetData(DataFormats.Text).ToString();
        richTextBox1.Text = richTextBox1.Text + s;
    }
}

Upvotes: 3

Views: 6369

Answers (2)

Josh
Josh

Reputation: 79

Drag and drop text within RXBox (RichTextBox):

Run HookOn_EventHandlers_etc() during Initialize(). Dragging mouse will fire the DragEnter and DragDrop events. In RXBox_DragDrop(), set DragDropEffects back to None.

    private void HookOnEventHandlers_etc()
    {
        RXBox.DragEnter += RXBox_DragEnter;
        RXBox.DragDrop += RXBox_DragDrop;

        RXBox.AllowDrop = true;
        RXBox.EnableAutoDragDrop = true;
    }

    private void RXBox_DragEnter(object sender, DragEventArgs e)
    {
        if (e.Data.GetDataPresent(DataFormats.Text))
            e.Effect = DragDropEffects.Copy;
        else
            e.Effect = DragDropEffects.None;
    }

    private void RXBox_DragDrop(object sender, DragEventArgs e)
    {
        RXBox.SelectedText = e.Data.GetData(DataFormats.Text).ToString();
        e.Effect = DragDropEffects.None; // with this the paste won't be doubled
    }

Upvotes: 3

M. Page
M. Page

Reputation: 2814

Well, I found myself a solution to this problem :

public partial class Form1 : Form {
    public Form1() {
        InitializeComponent();
        richTextBox1.EnableAutoDragDrop = true;
    }
}

And nothing more.

My first attempt was based on MSDN documentation: http://msdn.microsoft.com/en-us/library/aa984395(v=vs.71).aspx, but it seems broken.

Upvotes: 5

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