像ACDSee一樣用滑鼠拖曳大於表單的圖片 
本站之前也提供了一個類似的程式，但是那個程式限制當圖片比表單小時，必須將圖片置於表單左上角，否則程式執(zhí)行會有問題。以下提供的程式去除了這個限制，同時當圖片比表單小時會將圖片置於表單中央，這樣看起來比較美觀。

Option Explicit
Private gX As Long, gY As Long

Private Sub Form_Load()
Image1 = LoadPicture("c:\winnt\winnt256.bmp") '這個路徑可能要改
FitForm Image1
End Sub

Private Sub Form_Resize()
Call CenterImage(Image1)
End Sub

Private Sub Image1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
gX = X
gY = Y
End Sub

Private Sub Image1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Not Button = vbLeftButton Then Exit Sub
Dim dx As Long, dy As Long, ax As Long, ay As Long, t As Long, l As Long, tt As Long, ll As Long
With Image1
dy = Y - gY
dx = X - gX
ll = .Left
tt = .Top
l = Abs(ll)
t = Abs(tt)