弹出窗口杀手(上)(4)

[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);

}