使用user32.dll从外部应用程序的文本框（Unicode）中提取文本到C#应用程序中

Question

 private void button1_Click(object sender, EventArgs e)
    { IntPtr MytestHandle = new IntPtr(0x00060342);

        HandleRef hrefHWndTarget = new HandleRef(null, MytestHandle);

     // encode text into 
        richTextBox1.Text = ModApi.GetText(hrefHWndTarget.Handle);
     }

公共静态类ModApi{
[dllimport（“user32.dll”,EntryPoint=“sendmessageTimeout”,SetLastError=true,CharSet=CharSet.unicode)]公共静态extern uint SendMessageTimeoutText（IntPtr hWnd,int Msg,int countOfChars,StringBuilder text,uint flags,uint uTImeoutj,uint result）；

        public static string GetText(IntPtr hwnd)
        {
            var text = new StringBuilder(1024);

            if (SendMessageTimeoutText(hwnd, 0xd, 1024, text, 0x2, 1000, 0) != 0)
            {
                return text.ToString();
            }

            MessageBox.Show(text.ToString());
            return "";
        }
    }

Answer 1

您对WN_GETTEXT的使用不正确，请阅读文档:http://msdn.microsoft.com/en-us/library/windows/desktop/ms632627%28v=vs.85%29.aspx

wParam

The maximum number of characters to be copied, including the terminating null character. 

或者使用正确的函数:http://www.pinvoke.net/default.aspx/user32/getWindowtext.html

[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, [Out] StringBuilder lParam);

public static string GetWindowTextRaw(IntPtr hwnd)
{
    // Allocate correct string length first
    int length = (int)SendMessage(hwnd, WM_GETTEXTLENGTH, IntPtr.Zero, IntPtr.Zero);
    StringBuilder sb = new StringBuilder(length + 1);
    SendMessage(hwnd, WM_GETTEXT, (IntPtr)sb.Capacity, sb);
    return sb.ToString();
}

使其适应SendMessageTimeOut