獲取活動窗口文本（併發送更多文本）

我在C＃中創建了一個小工具，它會在按下全局熱鍵時將一些文本添加到活動文本框中，這是一種自動完成功能。我有我的全局熱鍵工作，但現在我不知道如何獲取當前文本在活動文本框（如果活動窗口是一個文本框是。）我迄今試過的是使用獲取活動窗口文本（併發送更多文本）

一個。 GetForegroundWindow，然後使用該句柄調用GetWindowText。這給了我活動窗口的窗口標題，而不是文本框內容。

灣GetActiveWindow並使用該句柄調用GetWindowText。這根本沒有給我任何文字。

這裏是我做了什麼

[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()); 
}

那麼，如何實現這一目標的任何想法的例子嗎？

編輯28.01.2009： 所以，我發現如何做到這一點。這是我用的：

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(); 
    } 
}

關於這個的一些說明。該示例在做任何事情之前等待5秒鐘，讓您有機會將焦點放在某個編輯窗口。在我的真實應用程序中，我使用熱鍵來觸發此事，但這隻會混淆此示例。另外，在生產代碼中，您應該檢查win32調用的返回值，以查看它們是否成功。

來源

2009-01-26 Einar Egilsson