Question

VB鼠标拖动无标题窗体代码

Private Declare Function ReleaseCapture Lib "user32" () As Long
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 Const WM_SYSCOMMAND = &H112
Private Const SC_MOVE = &HF010&
Private Const HTCAPTION = 2
Private Sub Command1_Click()
End
End Sub
Private Sub Form1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
ReleaseCapture
ret& = SendMessage(Me.hWnd, WM_SYS, SC_MOVE + HTCAPTION, 0)
'WM_SYS向窗体发送一个窗体移动命令
'SC_MOVE + HTCAPION单击左键移动窗体
End Sub
'
'
以上是完整的代码，当是不会动，请问是哪里错了？

Answer 1

Private Declare Function SetWindowPos& Lib "user32" (ByVal hwnd As Long, _
ByVal hWndInsertAfter As Long, ByVal X As Long, ByVal Y As Long, _
ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long)

Private Declare Function ReleaseCapture Lib "user32" () As Long
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 Const HTCAPTION = 2
Private Const WM_NCLBUTTONDOWN = &HA1

Private Sub Form1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
'拖动窗体
If Button = 1 Then ’注意这里，你的无法实现就是这里的问题，没有定义鼠标按下
ReleaseCapture
SendMessage hwnd, WM_NCLBUTTONDOWN, HTCAPTION, 0&
End If
End Sub