2024年2月8日发(作者：)
C#查找指定窗口的子窗口的句柄
用axWebBrowser加载HTML网页时，真正显示内容的窗体并不是axWebBrowser，而是其子窗口的子窗口一个名为Internet Explorer_Server的类。从spy++可知：
公司需要在网页上进行手写，需要对Internet Explorer_Server进行操作，而通过axWebBrowser的Handle不能直接操作Internet Explorer_Server。于是在网上搜到Paul
DiLascia写的一个CFindWnd类，是用C++写的，由于我用C#进行了改写。
这个类主要用的的API 是EnumChildWindows和FindWindowEx，第一个遍历指定窗口下的子窗口，第二个查找指定名称的窗口，如果找到返回此窗口Handle。
该类的用法：
FindWindow fw = new FindWindow(wndHandle, "ChildwndClassName"); //实例化，第一个参数是要查找的起始窗口的句柄；第二个参数是要查找的窗口的类的名称。现在我们需要的传的是"Internet Explorer_Server"。
IntPtr ip = andle;//FindWindow的公共属性FoundHandle就是查找到的窗口的句柄。
完整的类如下：
using System;
using c;
using ;
using pServices;
namespace y
{
///
/// This class is to find the given window's child window accroding to the given child window's name.
/// The useage: FindWindow fw = new FindWindow(wndHandle, "ChildwndClassName"); IntPtr ip = andle;
/// I adapt the code from Paul DiLascia,who is the MSDN Magazine's writer.
/// The original class is named CFindWnd which is written in C++, and you could get it on Internet.
/// is a great includes almost all the API fuctoin to be used in C#.
///
class FindWindow
{
[DllImport("user32")]
[return: MarshalAs()]
//IMPORTANT : LPARAM must be a pointer (InterPtr) in VS2005, otherwise an exception will be thrown
private static extern bool EnumChildWindows(IntPtr window, EnumWindowProc callback, IntPtr i);
//the callback function for the EnumChildWindows
private delegate bool EnumWindowProc(IntPtr hWnd, IntPtr parameter);
//if found return the handle , otherwise return
[DllImport("", EntryPoint = "FindWindowEx")]
private static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
private string m_classname; // class name to look for
private IntPtr m_hWnd; // HWND if found
public IntPtr FoundHandle
{
get { return m_hWnd; }
}
// ctor does the work--just instantiate and go
public FindWindow(IntPtr hwndParent, string classname)
{
m_hWnd = ;
m_classname = classname;
FindChildClassHwnd(hwndParent, );
}
///
/// Find the child window, if found m_classname will be assigned
///
/// parent's handle
/// the application value, nonuse
///
//The C++ code is that lParam is the instance of FindWindow class , if found assign the instance's m_hWnd
private bool FindChildClassHwnd(IntPtr hwndParent, IntPtr lParam)
{
EnumWindowProc childProc = new EnumWindowProc(FindChildClassHwnd);
IntPtr hwnd = FindWindowEx(hwndParent, , this.m_classname, );
if (hwnd != )
{
this.m_hWnd = hwnd; // found: save it
return false; // stop enumerating
}
EnumChildWindows(hwndParent, childProc, ); // recurse redo FindChildClassHwnd
return true;// keep looking
}
}
}
注意：在VS2005中，MDA检查的很严格，LPARAM是64位，要用IntPtr表示(网上有人用long来表示，我试了，MDA会抛出异常)。 是个不错的网站，它包含了几乎所有的API在.NET中的调用说明，还有例子。
附Paul DiLascia用C++写的CFindWnd类：
////////////////////////////////////////////////////////////////
// MSDN Magazine -- August 2003
// If this code works, it was written by Paul DiLascia.
// If not, I don't know who wrote it.
// Compiles with Visual Studio .NET on Windows XP. Tab size=3.
//
// ---
// This class encapsulates the process of finding a window with a given class name
// as a descendant of a given window. To use it, instantiate like so:
//
// CFindWnd fw(hwndParent,classname);
//
// fw.m_hWnd will be the HWND of the desired window, if found.
//
class CFindWnd {
private:
//////////////////
// This private function is used with EnumChildWindows to find the child
// with a given class name. Returns FALSE if found (to stop enumerating).
//
static BOOL CALLBACK FindChildClassHwnd(HWND hwndParent, LPARAM lParam) {
CFindWnd *pfw = (CFindWnd*)lParam;
HWND hwnd = FindWindowEx(hwndParent, NULL, pfw->m_classname, NULL);
if (hwnd) {
pfw->m_hWnd = hwnd; // found: save it
return FALSE; // stop enumerating
}
EnumChildWindows(hwndParent, FindChildClassHwnd, lParam); // recurse
return TRUE; // keep looking
}
public:
LPCSTR m_classname; // class name to look for
HWND m_hWnd; // HWND if found
// ctor does the work--just instantiate and go
CFindWnd(HWND hwndParent, LPCSTR classname)
: m_hWnd(NULL), m_classname(classname)
{
FindChildClassHwnd(hwndParent, (LPARAM)this);
}
};
2009年更新
通过实验得知，FindWindowEx可以通过classname或caption（也就是窗口的title）查找窗口，且如果第一个参数传的话，将从Windows最顶层窗口开始查找，但是窗口很多的话这样会非常的慢，所以加入Timeout的判断，如果超时还没找到，返回false。
用法：FindWindow fw = new FindWindow(, null, "ThunderDFrame", 10);//查找Title为ThunderDFrame的窗口，如果10秒内还没找到，返回false
代码如下：
using System;
using c;
using ;
using ;
using pServices;
namespace Util
{
class FindWindow
{
[DllImport("user32")]
[return: MarshalAs()]
//IMPORTANT : LPARAM must be a pointer (InterPtr) in VS2005,
otherwise an exception will be thrown
private static extern bool EnumChildWindows(IntPtr window,
EnumWindowProc callback, IntPtr i);
//the callback function for the EnumChildWindows
private delegate bool EnumWindowProc(IntPtr hWnd, IntPtr
parameter);
//if found return the handle , otherwise return
[DllImport("", EntryPoint = "FindWindowEx")]
private static extern IntPtr FindWindowEx(IntPtr hwndParent,
IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
private string m_classname; // class name to look for
private string m_caption; // caption name to look for
private DateTime start;
private int m_timeout;//If exceed the time. Indicate no
windows found.
private IntPtr m_hWnd; // HWND if found
public IntPtr FoundHandle
{
get { return m_hWnd; }
}
private bool m_IsTimeOut;
public bool IsTimeOut
{
get{return m_IsTimeOut;}
set { m_IsTimeOut = value; }
}
// ctor does the work--just instantiate and go
public FindWindow(IntPtr hwndParent, string classname, string
caption, int timeout)
{
m_hWnd = ;
m_classname = classname;
m_caption = caption;
m_timeout = timeout;
start = ;
FindChildClassHwnd(hwndParent, );
}
/**/
///
/// Find the child window, if found m_classname will be
assigned
///
/// parent's handle
/// the application value,
nonuse
///
//The C++ code is that lParam is the instance of FindWindow
class , if found assign the instance's m_hWnd
private bool FindChildClassHwnd(IntPtr hwndParent, IntPtr
lParam)
{
EnumWindowProc childProc = new
EnumWindowProc(FindChildClassHwnd);
IntPtr hwnd = FindWindowEx(hwndParent, ,
m_classname, m_caption);
if (hwnd != )
{
this.m_hWnd = hwnd; // found: save it
m_IsTimeOut = false;
return false; // stop enumerating
}
DateTime end = ;
if (onds(m_timeout) < end)
{
m_IsTimeOut = true;
return false;
}
EnumChildWindows(hwndParent, childProc, ); //
recurse redo FindChildClassHwnd
return true;// keep looking
}
}
}
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