获取活动窗口文本(并向其发送更多文本)

我在C#中创建一个小实用程序,当按下全局热键时,它会向活动文本框添加一些文本,这是一种自动完成功能.我有我的全局热键工作,但现在我不知道如何在活动文本框中获取当前文本(如果活动窗口是一个文本框).到目前为止我尝试过的是使用

一个.GetForegroundWindow然后使用该句柄调用GetWindowText.这给了我活动窗口的窗口标题,而不是文本框内容.

湾 GetActiveWindow并使用该句柄调用GetWindowText.这根本不给我任何文字.

这是我所做的一个例子

[DllImport("user32.dll")]
private static extern bool UnregisterHotKey(IntPtr hWnd, int id);
[ DllImport("user32.dll") ]
static extern int GetForegroundWindow();
[ DllImport("user32.dll") ]
static extern int GetWindowText(int hWnd, StringBuilder text, int count);   
[DllImport("user32.dll")]
static extern int GetActiveWindow();

public static void TestA() {
    int h = GetForegroundWindow();
    StringBuilder b = new StringBuilder();
    GetWindowText(h, b, 256);
    MessageBox.Show(b.ToString());
}

public static void TestB() {
    int h = GetActiveWindow();
    StringBuilder b = new StringBuilder();
    GetWindowText(h, b, 256);
    MessageBox.Show(b.ToString());
}

那么,关于如何实现这一点的任何想法？

编辑28.01.2009: 所以,我发现了如何做到这一点.这是我用过的:

using System;
using System.Text;
using System.Runtime.InteropServices;

public class Example
{
[DllImport("user32.dll")]
static extern int GetFocus();

[DllImport("user32.dll")]
static extern bool AttachThreadInput(uint idAttach, uint idAttachTo, bool fAttach);

[DllImport("kernel32.dll")]
static extern uint GetCurrentThreadId();

[DllImport("user32.dll")]
static extern uint GetWindowThreadProcessId(int hWnd, int ProcessId);    

[DllImport("user32.dll") ]
static extern int GetForegroundWindow();

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
static extern int SendMessage(int hWnd, int Msg, int wParam, StringBuilder lParam); 

const int WM_SETTEXT = 12;
const int WM_GETTEXT = 13;

public static void Main() 
{
    //Wait 5 seconds to give us a chance to give focus to some edit window,
    //notepad for example
    System.Threading.Thread.Sleep(5000);
    StringBuilder builder = new StringBuilder(500);

    int foregroundWindowHandle = GetForegroundWindow();
    uint remoteThreadId = GetWindowThreadProcessId(foregroundWindowHandle, 0);
    uint currentThreadId = GetCurrentThreadId();

    //AttachTrheadInput is needed so we can get the handle of a focused window in another app
    AttachThreadInput(remoteThreadId, currentThreadId, true);
    //Get the handle of a focused window
    int  focused = GetFocus();
    //Now detach since we got the focused handle
    AttachThreadInput(remoteThreadId, currentThreadId, false);

    //Get the text from the active window into the stringbuilder
    SendMessage(focused, WM_GETTEXT, builder.Capacity, builder);
    Console.WriteLine("Text in active window was " + builder);
    builder.Append(" Extra text");
    //Change the text in the active window
    SendMessage(focused, WM_SETTEXT, 0, builder);
    Console.ReadKey();
    }
}

关于此的一些注释.该示例在执行任何操作之前等待5秒,使您有机会将焦点放在某个编辑窗口上.在我真正的应用程序中,我使用热键来触发这个,但这只会混淆这个例子.此外,在生产代码中,您应该检查win32调用的返回值,以查看它们是否成功.