用VB获取计算器中的值

来源：互联网发布：改革开放1978 数据编辑：程序博客网时间：2024/06/05 11:29

代码如下，并加了一些注释

转自http://hi.baidu.com/ok100fen/blog/item/8b825a3a065522ed14cecb67.html

Option ExplicitPrivate Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As LongPrivate Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As LongPrivate Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As LongPrivate Const WM_GETTEXT = &HD   ''要想获得其他程序edit控件中的信息，只能通过发送WM_GETTEXT消息才能成功Private Const WM_GETTEXTLENGTH = &HE'执行这个方法前先用Shell "calc.exe"调用起计算器，先运算上几个数据做为测试Private Sub Command1_Click()      Dim ChildHwnd As Long      Dim Phwnd     As Long  　    Phwnd = FindWindow(vbNullString, "计算器") '用FindWindow函数得到计算器的句柄                                    　　　　　　　           If Phwnd <> 0 Then　　　    '在这里已经知道计算器里对那个编辑框的名字为"Edit"            '用FindWindowEx得到计算器里Edit的句柄。              ChildHwnd = FindWindowEx(Phwnd, 0&, "Edit", vbNullString)　　　　　　　　               Dim str As String * 256 '这里最好设置一个足够大的数　　　    '要想获得其他程序edit控件中的信息，只能通过发送WM_GETTEXT消息才能成功              '用SendMessage向系统发送消息从Edit里取值存到str里。              SendMessage ChildHwnd, WM_GETTEXT, 100, ByVal str '100是字符串的长度                 str = Trim(str)            txtText1.Text = str      End IfEnd Sub