C#

<br />
private void Startbtn_Click(Object sender, EventArgs e)<br />
{<br />
  Thread t = new Thread(new ThreadStart(try));<br />
  t.Start()<br />
}<br />
<br />
void try()<br />
{<br />
  int count = 0;<br />
  while (true)<br />
  {<br />
    if(count > 1000)<br />
    {<br />
      break;<br />
    }<br />
    Thread.Sleep(1000);<br />
    if(InvokeRequired)<br />
    Invoke(new new_try_delegate(new_try));<br />
    count++;<br />
  }<br />
}<br />
<br />
 public delegate void new_try_delegate();<br />
<br />
 void new_try()<br />
 {<br />
  textBox1.Text += "This is new Thread" + Environment.NewLine;<br />
 }<br />
<br />
<br />

public delegate void new_try_delegate();
new_try_delegate newTryEvent = new new_try_delegate(new_try);

public void new_try()
{
   if (this.InvokeRequired)
   {
      Invoke.Begin( newTryEvent );
   }
   else
   {
      textBox1.Text += "This is new Thread" + Environment.NewLine;
   }
}

<code>

    class Shell32Utils
    {
        const int FILENOASSOCIATED = 31;
        const int FILENOTFOUND = 2;
        const int PATHNOTFOUND = 3;
        const int SUCCESS = 32; //and longer
        const int BADFORMAT = 11;

        

        [DllImport("shell32", EntryPoint = "FindExecutable")]
        static extern int FindExecutable(string file, string directory, [MarshalAs(UnmanagedType.LPStr)] StringBuilder result);


        public static string Find(string file)
        {
            string fileName=System.IO.Path.GetFileName(file);
            string filePath = System.IO.Path.GetDirectoryName(file)+"\\";

            System.Text.StringBuilder res = new StringBuilder(1024);

            int stat = FindExecutable(fileName, filePath,  res);

            switch (stat)
            {
                case FILENOASSOCIATED: throw new Exception("File Not Associated");
                case FILENOTFOUND: throw new Exception("FileNot Found");

                case PATHNOTFOUND: throw new Exception("Path not Found");

                case BADFORMAT: throw new Exception("Bad Format");

                default: if (stat >= SUCCESS) return res.ToString();
                    else throw new Exception("Unknown Error");
            }
        }       
    }

</code>