Question

VB.NET中怎样用API获得文本框中的选中文本

现在只知道一个文本框的句柄，其在不同窗体，所以只能用API。请高手指教。

Answer 1

Public Declare Auto Function GetWindowText Lib "user32" Alias "GetWindowText" (ByVal hwnd As Integer, ByVal lpString As String, ByVal cch As Integer) As Integer
Public Declare Auto Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLength" (ByVal hwnd As Integer) As Integer

Public Function GetText(ByVal hwnd As Integer) As String
Dim nLen As Integer
nLen = GetWindowTextLength(hwnd)
GetText = Space(nLen)
GetWindowText(hwnd, GetText, nLen)
End Function

VS2008测试通过, 函数GetText传入的就是对应文本框的句柄.

追问

不行啊，返回的值是文本框中的全部内容啊。但我只想要选中内容。

追答

你已经获取了全部内容, 再在VB.NET里处理只取得部分内容不就行了...

追问

我怎么知道那一部分选中了！
程序运行后是由用户来操作，是用户选中的。

追答

Const EM_GETSEL = &HB0

Public Declare Auto Function GetWindowText Lib "user32" Alias "GetWindowText" (ByVal hwnd As Integer, ByVal lpString As String, ByVal cch As Integer) As Integer
Public Declare Auto Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLength" (ByVal hwnd As Integer) As Integer
Public Declare Auto Function SendMessage Lib "user32" Alias "SendMessage" (ByVal hwnd As Integer, ByVal message As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer

Public Function GetText(ByVal hwnd As Integer) As String
Dim nLen As Integer
nLen = GetWindowTextLength(hwnd)
GetText = Space(nLen)
GetWindowText(hwnd, GetText, nLen + 1)
End Function

Public Function GetSelText(ByVal hwnd As Integer) As String
Dim nRet As Integer
nRet = SendMessage(hwnd, EM_GETSEL, 0, 0)
Dim strText As String
strText = GetText(hwnd)
Dim nStart, nEnd As Integer
nStart = nRet And &HFFFF 'LOWORD(nRet) -> (nRet) & 0xFFFF
nEnd = (nRet / 65536) And &HFFFF 'HIWORD(nRet) -> (nRet >> 16) & 0xFFFF
If nEnd - nStart <= 0 Then
GetSelText = String.Empty
Exit Function
End If
GetSelText = strText.Substring(nStart, nEnd - nStart + 1)
End Function

调用GetSelText获取选中的文本

Answer 2

可以声明全局函数么 放在那个窗体里

追问

又会有什么用？

追答

public funtion tostr() as string
tostr=text
end function

那边调用

追问

现在的关键问题是只知道该文本框的句柄，不知道它的名称