How to set the TAB width in a Windows Forms TextBox control?

Question

Given a WinForms TextBox control with MultiLine = true and AcceptsTab == true, how can I set the width of the tab character displayed?

I wa

Answer 1

I think sending the EM_SETTABSTOPS message to the TextBox will work.

// set tab stops to a width of 4
private const int EM_SETTABSTOPS = 0x00CB;

[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr SendMessage(IntPtr h, int msg, int wParam, int[] lParam);

public static void SetTabWidth(TextBox textbox, int tabWidth)
{
    Graphics graphics = textbox.CreateGraphics();
    var characterWidth = (int)graphics.MeasureString("M", textbox.Font).Width;
    SendMessage
        ( textbox.Handle
        , EM_SETTABSTOPS
        , 1
        , new int[] { tabWidth * characterWidth }
        );
}

This can be called in the constructor of your Form, but beware: Make sure InitializeComponents is run first.

• Link at MSDN
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