[IE编程]如何消除Webbrowser控件切换时的闪烁?
环境：VS2005 C# XP
小弟以webbrowser控件为基础做一个多页面网页流览器，页面切换时会有相对明显的闪烁。经goole,网上找到这么一篇资料：
Web Browser控件和CHtmlView有什么具体应用我也不废话了，咱们开门见山吧。
通常使用上述两个东西的时候会发现切换的时候有很严重的闪烁。
仔细观察你会发现，比方在ChtmlView中，窗口的绘画过程是：先画View的背景，然后在上层画控件（即网页）
解决办法很简单，禁止View进行那无用的导致闪烁的绘制背景过程。
具体做法 :
在派生类里处理WM_ERASEBKGND消息
BOOL CMyHtmlView::OnEraseBkgnd(CDC* pDC)
{
return TRUE;
// return CHtmlView::OnEraseBkgnd(pDC);
}
通过上面的改动以后，你会发现VIEW会跟腾讯的QQ浏览器一样无闪烁：）
Web Browser控件的相应做法类似，不再详述
于是在Webbrowser控件里重写WndProc方法，截获该消息，但没有效果。重写OnPaintBackground，让它啥也不干，照样没效果。忽然想到Webbrowser不过是对底层axwebbrowser控件的封装，于是改用底层的axwebbrowser，还是重写WndProc和OnPaintBackground，结果令人大失所望，页面切换时闪烁依旧。
请问有什么好的办法吗？
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支持这篇文章
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没看懂哦，我做的时候没这个问题
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路过过不去
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自己顶一下
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该问题可以这样概括：
双缓冲有效解决了自定义控件闪烁问题，但对于一些系统控件而且不能设置双缓冲的控件比如Webbrowser,如何防止其闪烁呢？
难道我得回归VC了？
[其他解释]
用webbrowser控件做多标签式的浏览器，当点击标签切换不同页面时会有闪烁---当页面以黑色为背景时尤其明显
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解决方法如下:
从WebBrowser派生一个新类
构造函数中添加DocumentCompleted事件响应
相关代码:
[DllImport("user32.dll")]
protected static extern int GetWindowLong(int hwindow, int unindex);
[DllImport("user32.dll")]
protected static extern int CallWindowProc(int lpPrevWndFunc, int hWnd, int Msg, int wParam, int lParam);
[DllImport("user32.dll")]
protected static extern int SetWindowLong(int hwindow, int unindex, CallWindowProcDelegate lnewvalue);
public static int oldWindow = 0;
public const int GWL_WNDPROC = -4;
public delegate int CallWindowProcDelegate(int Wnd, int Msg, int WParam, int LParam);
public CallWindowProcDelegate MyCallWindowProc;
bool add = false;
void ExtendWebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
if(add)
{ return; }
add = true;
FindWindow fw = new FindWindow(this.Handle, "Internet Explorer_Server");
IntPtr hIE = fw.FoundHandle;
if (hIE.ToInt32() != 0)
{
oldWindow = (int)GetWindowLong(hIE.ToInt32(), GWL_WNDPROC);
MyCallWindowProc = new CallWindowProcDelegate(WndProc);
SetWindowLong(hIE.ToInt32(), GWL_WNDPROC, MyCallWindowProc);
}
}
private int WndProc(int Wnd, int Msg, int WParam, int LParam)
{
const int WM_ERASEBKGND = 0x14;
if (Msg == WM_ERASEBKGND)
{
return 1;
}
return CallWindowProc(oldWindow, Wnd, Msg, WParam, LParam);
}
/**/
/// <summary>
/// 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 = fw.FoundHandle;
/// 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.
/// www.pinvoke.net is a great website.It includes almost all the API fuctoin to be used in C#.
/// </summary>
class FindWindow
{
[DllImport("user32")]
[return: MarshalAs(UnmanagedType.Bool)]
//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 IntPtr.Zero
[DllImport("user32.dll", 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 = IntPtr.Zero;
m_classname = classname;
FindChildClassHwnd(hwndParent, IntPtr.Zero);
}
//EnumChildWindows是API函数，能够遍历主窗口下所有子窗口。不过它的遍历过程是通过
//第二个参数即回调函数与程序员交互的。EnumChildWindows每找到一个窗口。就调用回调
//函数。回调函数如果返回false。遍历就会结束。
/**/
/// <summary>
/// Find the child window, if found m_classname will be assigned
/// </summary>
/// <param name="hwndParent">parent's handle</param>
/// <param name="lParam">the application value, nonuse</param>
/// <returns>found or not found</returns>
//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, IntPtr.Zero, this.m_classname, string.Empty);
if (hwnd != IntPtr.Zero)
{
this.m_hWnd = hwnd; // found: save it
return false; // stop enumerating
}
EnumChildWindows(hwndParent, childProc, IntPtr.Zero); // recurse redo FindChildClassHwnd
return true;// keep looking
}
}
