Textbox_KeyPress Event using vb.net or c#

Question

My requirement is i am trying to develop a text editor for my mother tongue language. That is i am trying to develop tamil text editor using unicode characters. When i am pres

Answer 1

this TextBox, adds "jj" when the user presses k key. The cursor position is corrcted.

public class MyTextBox : TextBox
{

    protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
    {
        if (keyData == Keys.K)
        {
            int pos = this.SelectionStart;
            this.Text = this.Text.Substring(0, this.SelectionStart) + "jj" 
            + this.Text.Substring(this.SelectionStart);
            this.SelectionStart = pos + 2;
            return true;
        }
        return base.ProcessCmdKey(ref msg, keyData);
    }
}

Answer 2

You need to update the SelectionStart Property and increase its length with the size of the new text inserted. Something like:

int curPos = txtEditor.SelectionStart;
if (e.KeyChar == 'k')
{
    txtEditor.Text=txtEditor.Text.Insert(txtEditor.SelectionStart, "jj");
    txtEditor.SelectionLength = 0;
}
txtEditor.SelectionStart = curPos + 2; //or whatever the length of text u inserted    

Answer 3

You need to stop the textbox from rendering, while you update the cursor position. I had done something similar before with a console application. But can't find the code to reference it here.