这个小例子就是用来演示如何得到Windows桌面上处于活动状态的窗口的句柄的。
使用一个Timer控件就可以搞定。在本例中再通过GetWindowText函数来处理得到句柄后的操作。
1。新建一个标准VB6的EXE工程，加入Timer控件
2。API函数的声明
private Declare Function GetForegroundWindow Lib "user32" () as Long
private Declare Function GetWindowText Lib "user32" _
Alias "GetWindowTextA" (byval hwnd as Long, _
byval lpString as string, byval cch as Long) as Long
3。在窗体的Load事件中加入代码：
Private Sub Form_Load()
Timer1.Interval = 100 '设置间隔时间
End Sub
4。在Timer控件中的Timer事件中加入代码：
Private Sub Timer1_Timer()
Static CurrentHwnd As Long
Dim ForegroundWindowHwnd As Long
Dim sText As String * 255
ForegroundWindowHwnd = GetForegroundWindow
If ForegroundWindowHwnd = CurrentHwnd Then Exit Sub
CurrentHwnd = ForegroundWindowHwnd
If CurrentHwnd <> hwnd Then
Caption = "ActiveWidow's Caption: " & Left$(sText, GetWindowText(CurrentHwnd, sText, 255))
Else
Caption = "ActiveWindow's Caption: Form1"
End If
End Sub
本程序在Win2000 + Vb6 中调试通过
