c# 动态改变控件大小的方法

[DllImport("user32.dll", EntryPoint="GetWindowLong")]
  public static extern int GetWindowLong (
   int hwnd,
   int nIndex
   );
  [DllImport("user32.dll", EntryPoint="SetWindowLong")]
  public static extern int SetWindowLong (
   int hwnd,
   int nIndex,
   int dwNewLong
   );
  [DllImport("user32.dll", EntryPoint="SetWindowPos")]
  public static extern int SetWindowPos (
   int hwnd,
   int hWndInsertAfter,
   int x,
   int y,
   int cx,
   int cy,
   int wFlags
   );
  public const int GWL_STYLE = (-16);
  public const int WS_THICKFRAME =  0x40000;
  const int SWP_NOSIZE = 0x1;
  const int SWP_NOMOVE = 0x2;
  const int  SWP_NOZORDER = 0x4;
  const int  SWP_FRAMECHANGED = 0x20 ;
  private void button1_Click(object sender, System.EventArgs e)
  {
   int style = GetWindowLong((int)this.textBox1.Handle,GWL_STYLE);
   style |=WS_THICKFRAME;
   SetWindowLong((int)this.textBox1.Handle,GWL_STYLE,style);
   SetWindowPos((int)this.textBox1.Handle,(int)this.Handle,0,0,0,0,SWP_NOZORDER|SWP_NOSIZE|SWP_NOMOVE|SWP_FRAMECHANGED);
  }