如何用VB.NET的FindWindowEx在另一程序中定位messagebox窗口？

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我有Visual Basic应用，需要找到Microsoft Access，它有一个消息框，然后按下Enter键到消息框。我跟着这篇文章（FindWindow, FindWindowEx），它找到了Access并将其带到前台，但它不想找到消息框并将其带到前台。

我有一个visual basic应用程序需要找到Microsoft Access,它有一个消息框,然后Send Enter到消息框.

我跟着这篇文章(FindWindow FindWindowEx).

它找到Access并将其带到前台,但它不想找到消息框并将其带到前面：

Public Class Form1 Private Declare Function SetForegroundWindow Lib "user32" (ByVal hwnd As IntPtr) As Long Private Declare Auto Function FindWindow Lib "user32.dll" ( _ ByVal lpClassName As String, _ ByVal lpWindowName As String _ ) As IntPtr Private Declare Auto Function FindWindowEx Lib "user32.dll" ( _ ByVal hwndParent As IntPtr, _ ByVal hwndChildAfter As IntPtr, _ ByVal lpszClass As String, _ ByVal lpszWindow As String _ ) As IntPtr Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load Dim hWnd As IntPtr hWnd = FindWindow("OMain", Nothing) MsgBox(hWnd) 'FINDS 1640402 Dim hWndChild1 As IntPtr = _ FindWindowEx(hWnd, IntPtr.Zero, "#32770 (Dialog)", "Microsoft Access") MsgBox(hWndChild1) 'FIRST PROBLEM IT FINDS ZERO HERE Dim hWndChild1Button As IntPtr = _ FindWindowEx(hWndChild1, IntPtr.Zero, "Button", "OK") MsgBox(hWndChild1Button) 'ALSO FINDS ZERO HERE If hWndChild1Button <> IntPtr.Zero Then SetForegroundWindow(hWndChild1Button) SendKeys.SendWait("{Enter}") End If End Sub End Class

代码未使用正确的winapi函数. FindWindowEx()可以找到子窗口,但MsgBox()显示的窗口不是子窗口.它是一个顶级窗口,您可以使用FindWindow()找到它.

但该功能不足以找到您要关闭的特定消息框.需要一种更好的方法,您可以使用的方法是使用EnumThreadWindows()枚举同一线程拥有的窗口.关于MsgBox()的好处是,由于对话框是模态的,因此只有一个这样的窗口.

SendKeys()也不够精确,如果消息框在前台,它只能正常工作.更好的方法是通过向BM_CLICK消息发送实际单击按钮.使用Access表单测试的代码：

Imports System.Runtime.InteropServices Imports System.ComponentModel Imports System.Text Module Module1 Sub Main() '' Find the MS-Access host window Dim access = FindWindow("OMain", Nothing) If access = IntPtr.Zero Then Throw New Win32Exception() '' Enumerate the windows owned by the same thread Dim pid As Integer Dim tid = GetWindowThreadProcessId(access, pid) If tid = 0 Then Throw New Win32Exception() EnumThreadWindows(tid, AddressOf ClickOkButton, Nothing) End Sub Private Function ClickOkButton(hWnd As IntPtr, lp As IntPtr) As Boolean '' Verify the class name is #32770 Dim buf As New StringBuilder(256) GetClassName(hWnd, buf, 256) If buf.ToString <> "#32770" Then Return True '' Find the OK button (control ID 2) Dim okbutton = GetDlgItem(hWnd, 2) If okbutton = IntPtr.Zero Then Return True '' Activate the dialog, just in case SetActiveWindow(hWnd) '' Click the button SendMessage(okbutton, BM_CLICK, IntPtr.Zero, IntPtr.Zero) '' Done, no need to continue enumerating windows Return False End Function End Module Friend Module NativeMethods <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> Friend Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr End Function <DllImport("user32.dll", SetLastError:=True)> Friend Function GetWindowThreadProcessId(ByVal hwnd As IntPtr, ByRef lpdwProcessId As Integer) As Integer End Function Friend Delegate Function EnumThreadDelegate(hWnd As IntPtr, lParam As IntPtr) As Boolean <DllImport("user32.dll", SetLastError:=True)> Friend Function EnumThreadWindows(dwThreadId As Int32, lpfn As EnumThreadDelegate, lParam As IntPtr) As Boolean End Function <DllImport("user32.dll", CharSet:=CharSet.Auto)> Friend Function GetClassName(ByVal hWnd As System.IntPtr, ByVal lpClassName As System.Text.StringBuilder, ByVal nMaxCount As Integer) As Integer End Function <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> Friend Function GetDlgItem(ByVal hDlg As IntPtr, id As Integer) As IntPtr End Function <DllImport("user32.dll", SetLastError:=True)> Friend Function SetActiveWindow(ByVal hWnd As IntPtr) As IntPtr End Function <DllImport("user32.dll")> Friend Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wp As IntPtr, ByVal lp As IntPtr) As IntPtr End Function Friend Const BM_CLICK As Integer = &HF5 End Module

通常的建议是favor UI Automation.