本地win32窗体查找

本地win32窗体查找

 本程序的实现原理是这样,先检查所有的IE窗口标题,然后于已经有的列表来比较,如果有相同的,我们就关闭这个窗口.

按照上面的方法,我们每n妙使用KillPopup()来检查.比较遗憾的是我们无法使用安全代码来完成所有的工作. 我们可以使用 System.Diagnostics.Proces来检查所有的IE进程,然后得到主窗体.但是每一个IE进程可以打开好几个窗口,虽然每一个窗体都于一个进程相关,但是还没有办法来使每一个窗体于进程对应起来.
一个可行的办法使用System.Diagnostics.Process列举出所有的运行的进程,然后System.Diagnostics.ProcessThreadCollection 来得到他们的.Threads属性,为了得到thread Id,我们使用Win32 API EnumThreadWindows(DWORD threadId, WNDENUMPROC lpfn, LPARAM lParam) 来实现,这是一个回调(call back)函数,他可以列举出于进程相关的窗体. 当我们得到了窗体的句柄以后,我们可以使用另一个API函数 GetWindowText(HWND hwnd, /*out*/LPTSTR lpString, int nMaxCount)来得到窗体的标题,然后根据已经有的窗体,调用API函数SendMessage(HWND hWnd, int msg, int wParam, int lParam)来关闭窗口. 下面使演示代码

Process[] myProcesses = Process.GetProcessesByName("IEXPLORE");

foreach(Process myProcess in myProcesses)
{
    FindPopupToKill(myProcess);
}

protected void FindPopupToKill(Process p)
{
    // traverse all threads and enum all windows attached to the thread
    foreach (ProcessThread t in p.Threads)
    {
        int threadId = t.Id;
 
        NativeWIN32.EnumThreadProc callbackProc =
            new NativeWIN32.EnumThreadProc(MyEnumThreadWindowsProc);
        NativeWIN32.EnumThreadWindows(threadId, callbackProc, IntPtr.Zero /*lParam*/);
    }
}

// callback used to enumerate Windows attached to one of the threads
bool MyEnumThreadWindowsProc(IntPtr hwnd, IntPtr lParam)
{
    public const int WM_SYSCOMMAND = 0x0112;
    public const int SC_CLOSE = 0xF060;

    // get window caption
    NativeWIN32.STRINGBUFFER sLimitedLengthWindowTitle;
    NativeWIN32.GetWindowText(hwnd, out sLimitedLengthWindowTitle, 256);

    String sWindowTitle = sLimitedLengthWindowTitle.szText;
    if (sWindowTitle.Length==0) return true;

    // find this caption in the list of banned captions
    foreach (ListViewItem item in listView1.Items)
    {
        if ( sWindowTitle.StartsWith(item.Text) )
            NativeWIN32.SendMessage(hwnd, NativeWIN32.WM_SYSCOMMAND,
                                          NativeWIN32.SC_CLOSE,
                                          IntPtr.Zero);  // try soft kill
    }

    return true;
}

public class NativeWIN32
{
    public delegate bool EnumThreadProc(IntPtr hwnd, IntPtr lParam);

    [DllImport("user32.dll", CharSet=CharSet.Auto)]
    public static extern bool EnumThreadWindows(int threadId, EnumThreadProc pfnEnum, IntPtr lParam);

    // used for an output LPCTSTR parameter on a method call
    [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)]
    public struct STRINGBUFFER
    {
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst=256)]
        public string szText;
    }

    [DllImport("user32.dll", CharSet=CharSet.Auto)]
    public static extern int GetWindowText(IntPtr hWnd,  out STRINGBUFFER ClassName, int nMaxCount);

    [DllImport("user32.dll", CharSet=CharSet.Auto)]
    public static extern int SendMessage(IntPtr hWnd, int msg, int wParam, int lParam);
}

上面的方法在性能上是不错的,因为他过滤了其他非IE的窗口.但是我们可以用一个更简单的方法来实现,就是调用API FindWindowEx(HWND hWndParent, HWND hWndNext, /*in*/LPCTSTR szClassName, /*in*/LPCTSTR szWindowTitle)方法.比较有用的是这句,我们可以使用registered window class name来找到IE窗口(IEFrame是所有打开的IE的标识).
 
protected void FindPopupToKill()
{
    IntPtr hParent = IntPtr.Zero;
    IntPtr hNext = IntPtr.Zero;
    String sClassNameFilter = "IEFrame"; // 所有IE窗口的类
    do
    {
        hNext = NativeWIN32.FindWindowEx(hParent,hNext,sClassNameFilter,IntPtr.Zero);

        // we've got a hwnd to play with
        if ( !hNext.Equals(IntPtr.Zero) )
        {
            // get window caption
            NativeWIN32.STRINGBUFFER sLimitedLengthWindowTitle;
            NativeWIN32.GetWindowText(hNext, out sLimitedLengthWindowTitle, 256);

            String sWindowTitle = sLimitedLengthWindowTitle.szText;
            if (sWindowTitle.Length>0)
            {
                // find this caption in the list of banned captions
                foreach (ListViewItem item in listView1.Items)
                {
                    if ( sWindowTitle.StartsWith(item.Text) )
                        NativeWIN32.SendMessage(hNext, NativeWIN32.WM_SYSCOMMAND,
                                                       NativeWIN32.SC_CLOSE,
                                                       IntPtr.Zero); // try soft kill
                }
            }
        }
    }
    while (!hNext.Equals(IntPtr.Zero));

}

public class NativeWIN32
{
    [DllImport("user32.dll", CharSet=CharSet.Auto)]
    public static extern IntPtr FindWindowEx(IntPtr parent /*HWND*/,
                                             IntPtr next /*HWND*/,
                                             string sClassName, 
                                             IntPtr sWindowTitle);

}
代码下载: http://www.codeproject.com/useritems/popupkiller/popupkiller_src_update.zip
演示程序: http://www.codeproject.com/useritems/popupkiller/popupkiller_demo_update.zip