ListViewWithoutFocus.cs

ListViewWithoutFocus.cs

// Copyright Matthew King 2014.
// Licensed under the Boost Software License, Version 1.0.

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

/// <summary>
/// Extends the System.Windows.Forms.ListView class, removing the focus indicators.
/// </summary>
class ListViewWithoutFocus : ListView
{
    /// <summary>
    /// Sends the specified message to a window or windows. The SendMessage function calls
    /// the window procedure for the specified window and does not return until the window
    /// procedure has processed the message.
    /// </summary>
    /// <param name="hWnd">A handle to the window that will receive the message.</param>
    /// <param name="wMsg">The message to be sent.</param>
    /// <param name="wParam">Additional message-specific information.</param>
    /// <param name="lParam">Additional message-specific information.</param>
    /// <returns>The result of the message processing.</returns>
    [DllImport("user32.dll")]
    private static extern int SendMessage(IntPtr hWnd, int wMsg, int wParam, int lParam);

    /// <summary>
    /// Raises the System.Windows.Forms.ListView.SelectedIndexChanged event.
    /// </summary>
    /// <param name="e">An System.EventArgs that contains the event data.</param>
    protected override void OnSelectedIndexChanged(EventArgs e)
    {
        base.OnSelectedIndexChanged(e);
        this.HideFocusIndicators();
    }

    /// <summary>
    /// Raises the System.Windows.Forms.Control.Enter event.
    /// </summary>
    /// <param name="e">An System.EventArgs that contains the event data.</param>
    protected override void OnEnter(EventArgs e)
    {
        base.OnEnter(e);
        this.HideFocusIndicators();
    }

    /// <summary>
    /// Hide focus indicators.
    /// </summary>
    private void HideFocusIndicators()
    {
        // wMsg = 0x127 (WM_CHANGEUISTATE)
        // wParam = 0x10001 (UIS_SET | UISF_HIDEFOCUS)
        //          low-order word UIS_SET (0x1), high-order word UISF_HIDEFOCUS (0x1)
        SendMessage(this.Handle, 0x127, 0x10001, 0);
    }
}