VB2010中关于使用SendMessage API向外部程序控件中输入字符串的问题。
各位大侠，小弟菜鸟，因工作需要，临时捉刀，需要一个小软件实现这样一个功能，软件启动，在系统中注册一个全局热键，然后，每当按这个热键的时候，程序自动的在光标当前位置（网页，程序文本框，记事本程序等）输入系统时间戳。我的全部代码如下：
Public Class Main
Declare Function RegisterHotKey Lib "user32" (ByVal hwnd As Integer, ByVal id As Integer, ByVal fsModifiers As Integer, ByVal vk As Integer) As Integer
Declare Function WindowFromPoint Lib "user32" (ByVal xPonit As Integer, ByVal yPonit As Integer) As IntPtr
Private Declare Function GetCursorPos Lib "user32" (ByRef lpPoint As POINTAPI) As Integer
Private Declare Function SendMessage Lib "user32" (ByVal hwnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As String) As Integer
Public Const MOD_ALT = &H1
Public Const WM_SETTEXT = &HC
Private Structure POINTAPI
Dim x As Integer
Dim y As Integer
End Structure
Public Sub ww()
Dim a As POINTAPI
Dim b As IntPtr
Dim bb As Long
GetCursorPos(a)
b = WindowFromPoint(a.x, a.y)
Label2.Text = b
bb = CLng(b)
SendMessage(b, WM_SETTEXT, 0, CStr(Now))
End Sub
Public Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load, Timer1.Tick
RegisterHotKey(Handle, 101, MOD_ALT, Keys.R)
End Sub
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
If m.Msg = 786 Then
If m.WParam.ToInt32 = 101 Then
'MsgBox(CStr(Now))
Label1.Text = CStr(Now)
Call ww()
End If
End If
MyBase.WndProc(m)
End Sub
End Class
运行时竟然会提示“Unable to find an entry point named 'SendMessage' in DLL 'user32'.”。
快崩溃了。。。大侠们帮帮忙啊…………谢谢各位了，问题究竟出在哪里呢。。。 --------------------编程问答-------------------- 试下这个：
Private Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam As Int32, ByVal lParam As Int32) As Int32--------------------编程问答-------------------- 貌似还是不行，一样的现象。。
大戏们针对我的 需求，有什么更好的实现方法吗？我菜鸟。。。
补充：VB , API
