Button inside a WinForms textbox

Question

Do WinForms textboxes have any properties that make an embedded button, at the end of the box, possible?

Something like the favorites button on the Chrome address bo

Answer 1

Here's the answer wrapped in a TextBox subclass.

public class ButtonTextBox : TextBox {
    private readonly Button _button;

    public event EventHandler ButtonClick { add { _button.Click += value; } remove { _button.Click -= value; } }

    public ButtonTextBox() {
        _button = new Button {Cursor = Cursors.Default};
        _button.SizeChanged += (o, e) => OnResize(e);
        this.Controls.Add(_button); 
    }

    public Button Button {
        get {
            return _button;
        }
    }

    protected override void OnResize(EventArgs e) {
        base.OnResize(e);
        _button.Size = new Size(_button.Width, this.ClientSize.Height + 2);
        _button.Location = new Point(this.ClientSize.Width - _button.Width, -1);
        // Send EM_SETMARGINS to prevent text from disappearing underneath the button
        SendMessage(this.Handle, 0xd3, (IntPtr)2, (IntPtr)(_button.Width << 16));
    }

    [System.Runtime.InteropServices.DllImport("user32.dll")]
    private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, IntPtr lp);

}