VB自由拖动控件的代码

  其实原理很简单，和拖动无标题窗口的原理是一样的，当出发mousedown事件的时候发送消息duttondown到caption上。只要是从窗体继承来的就都可以使用这个原理，代码如下：

Option Explicit
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Declare Function ReleaseCapture Lib "user32" () As Long
Private Const WM_NCLBUTTONDOWN = &HA1
Private Const HTCAPTION = 2
Private Sub Command1_MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)
  ReleaseCapture
  SendMessage Command1.hwnd, WM_NCLBUTTONDOWN, HTCAPTION, 0
End Sub