C#

<br />
treeview_AfterSelect(...){ //first click selects the node<br />
treeview.selectedNode.BackColor = SystemColors.Highlight;<br />
}<br />
<br />
treeview_Click(...){<br />
//if the node is clicked the first time, AfterSelect will reset the color<br />
//after every additional click the node stays red<br />
treeview.SelectedNode.BackColor = Color.Red;<br />
}<br />

NET SEND * /domain:TEXTDOM This is my test message...

string myDomainName = Environment.UserDomainName;
string theMessage = "This is a test.";
Process.Start("net.exe", string.Format("send * /domain:{0} {1}",
  myDomainName, theMessage));

public sealed class NetSend
{
  public NetSend() {}
  // Define fields and properties to get/set those fields.
 
  public Send()
  {
    // Only works in Windows NT-based OSes.
    if (Environment.OSVersion.Platform == PlatformID.Win32Windows)
      throw new NotSupportException();
 
    // Alloc your buffers using the NetApiBufferAllocate API, send
    // your message and free the string buffer.
  }
  [DllImport("netapi32.dll", CharSet=CharSet.Unicode)]
  private static extern uint NetMessageBufferSend(
    string servername, // null is local machine
    string msgalias,
    string fromname,
    byte[] msg,
    uint msglen);
  [DllImport("netapi32.dll")]
  private static extern uint NetApiBufferAllocate(
    uint byteCount,
    out IntPtr ptr);
  [DllImport("netapi32.dll")]
  private static extern uint NetApiBufferFree(
    IntPtr ptr);
}