跟踪WPF中的AccessViolationException [英] Tracking down a AccessViolationException in WPF
问题描述
我编写了一个WPF应用程序，该应用程序使用了许多Frame控件来查看相机供稿。部署后，它几乎随机崩溃（从2个小时到16个小时以上），我在事件日志中连续看到这些崩溃：
I've written a WPF application that uses many Frame controls to view camera feeds. When deployed, it crashes pretty randomly (anywhere from 2 hours to 16+ hours), and I see these in the event log, consecutively:
System.AccessViolationException：
尝试读取或写入受保护的
内存。这通常表示
其他内存已损坏。在
系统处的MS.Win32.UnsafeNativeMethods.DispatchMessage（MSG&
msg）在
的System.Windows.Threading.Dispatcher.PushFrameImpl（DispatcherFrame
帧）在
的系统。
处的Windows.Threading.Dispatcher.PushFrame（DispatcherFrame
帧）System.Windows.Threading.Dispatcher.Run（）
在
System.Windows.Application.RunDispatcher（Object
忽略）在
处System.Windows.Application.RunInternal（Window
窗口）在
System.Windows.Application.Run（Window
窗口）在
System.Windows.Application.Run（）位于
Status_Station_client.MainClass.Main（）
System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt. at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg) at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame) at System.Windows.Threading.Dispatcher.Run() at System.Windows.Application.RunDispatcher(Object ignore) at System.Windows.Application.RunInternal(Window window) at System.Windows.Application.Run(Window window) at System.Windows.Application.Run() at Status_Station_client.MainClass.Main()
对应用程序状态站进行故障排除
client.exe，版本1.0 .0.0，标记
4ad0faa5，故障模块msvfw32.dll，
版本5.1.2600.2180，标记41109753，
调试？ 0，故障地址为0x00002642。
Faulting application status station client.exe, version 1.0.0.0, stamp 4ad0faa5, faulting module msvfw32.dll, version 5.1.2600.2180, stamp 41109753, debug? 0, fault address 0x00002642.
关于如何跟踪此问题的任何想法？网页上确实包含ActiveX控件，所以首先想知道这里是否存在问题。
Any ideas on how to track this down? The web pages do contain ActiveX controls, so a first guess is there's a problem there.
我无法在调试模式下进行跟踪。我想到要尝试的另一件事是吞下导航调用中的异常，但是不确定这样做是否明智：
I haven't been able to trace this in Debug mode. Another thing I have thought of trying is swallowing the exception from the navigation call, but am unsure if this is a wise thing to do:
try
{
if (Frame1 != null)
Frame1.Source = new Uri(uriWithResolution);
}
catch (AccessViolationException ex)
{
// log message
}
编辑：这是更多的源代码，我对错误的位置（即抛出异常的位置）感到困惑
Here's some more source code, I'm stumped as to where the error is (i.e. where the exception is being thrown)
MatrixView.cs：
MatrixView.cs:
public partial class MatrixView : Window
{
System.Timers.Timer timer;
int pageNumber = 0;
IEnumerable<List<CameraInfo>> _cameraList;
GlobalSettings _globalSettings;
Screen _screen;
public MatrixView(List<CameraInfo> cameras, int pageFlipInterval, int camerasPerPage, GlobalSettings globalSettings, Screen screen)
{
InitializeComponent();
_globalSettings = globalSettings;
_screen = screen;
_cameraList = Partition<CameraInfo>(cameras, camerasPerPage);
this.Dispatcher.UnhandledException += new DispatcherUnhandledExceptionEventHandler(Dispatcher_UnhandledException);
displayCameras();
timer = new System.Timers.Timer(pageFlipInterval * 1000); // interval (in seconds) * 1000 ms / s
timer.Elapsed += new ElapsedEventHandler(timer_Elapsed);
timer.Enabled = true;
this.KeyUp += new System.Windows.Input.KeyEventHandler(MatrixView_KeyUp);
if (globalSettings.FullScreenOnLoad)
{
this.WindowStyle = WindowStyle.None;
}
}
void MatrixView_KeyUp(object sender, System.Windows.Input.KeyEventArgs e)
{
if (this.WindowStyle == WindowStyle.None)
{
if (e.Key == Key.F11 || e.Key == Key.Escape)
{
this.WindowStyle = WindowStyle.SingleBorderWindow;
}
}
else
{
if (e.Key == Key.F11)
{
this.WindowStyle = WindowStyle.None;
}
}
this.WindowState = WindowState.Maximized;
}
void timer_Elapsed(object sender, ElapsedEventArgs e)
{
this.Dispatcher.BeginInvoke(DispatcherPriority.Normal, new ThreadStart(delegate()
{
displayCameras();
}));
}
void Dispatcher_UnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
{
EventLog.WriteEntry("Matrix Monitor", string.Format("Unhandled exception from Matrix Dispatcher\r\nMessage: {0}\r\nSource: {1}\r\nInnerException: {2}\r\nStack Trace: {3}\r\nFull String: {4}", e.Exception.Message, e.Exception.Source, e.Exception.InnerException, e.Exception.StackTrace, e.Exception.ToString()));
e.Handled = true;
}
private void displayCameras()
{
foreach (var child in uniformGrid1.Children)
{
FrameTimer c = child as FrameTimer;
if (c != null)
{
c.Dispose();
c = null;
}
}
GC.Collect();
GC.WaitForPendingFinalizers();
uniformGrid1.Children.Clear();
List<CameraInfo> camerasInPage = _cameraList.ElementAt(pageNumber);
int numCameras = camerasInPage.Count;
int sqrtOfCameras = (int) Math.Sqrt(numCameras);
double height = _screen.Bounds.Height / sqrtOfCameras;
double width = _screen.Bounds.Width / sqrtOfCameras;
foreach (CameraInfo camera in camerasInPage)
{
uniformGrid1.Children.Add(new FrameTimer(camera, _globalSettings, height, width));
}
pageNumber++;
if (pageNumber >= _cameraList.Count<List<CameraInfo>>())
{
pageNumber = 0;
}
}
public static IEnumerable<List<T>> Partition<T>(IList<T> source, int size)
{
int remainder = source.Count % size == 0 ? 0 : 1;
for (int i = 0; i < (source.Count / size) + remainder; i++)
yield return new List<T>(source.Skip(size * i).Take(size));
}
}
FrameTimer.cs：
FrameTimer.cs:
public partial class FrameTimer : UserControl, IDisposable
{
System.Timers.Timer timer;
string _uri;
string _noImageUrl;
bool? _successState = null;
GlobalSettings _globalSettings;
CameraInfo _camera;
Ping ping;
double _height;
double _width;
public FrameTimer(CameraInfo camera, GlobalSettings globalSettings, double height, double width)
{
InitializeComponent();
_noImageUrl = AppDomain.CurrentDomain.BaseDirectory + "noImage.jpg";
_globalSettings = globalSettings;
_camera = camera;
_height = height;
_width = width;
_uri = string.Format("http://{0}:{1}/LiveView.aspx?camera={2}", globalSettings.ServerIPAddress, globalSettings.ServerPort, camera.camName);
this.Dispatcher.UnhandledException += new DispatcherUnhandledExceptionEventHandler(Dispatcher_UnhandledException);
setUrl();
timer = new System.Timers.Timer(_globalSettings.PingInterval * 1000);
timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
timer.Enabled = true;
}
void Dispatcher_UnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
{
EventLog.WriteEntry("Matrix Monitor", string.Format("Unhandled exception from Frame Dispatcher\r\nMessage: {0}\r\nSource: {1}\r\nInnerException: {2}\r\nStack Trace: {3}\r\nFull String: {4}", e.Exception.Message, e.Exception.Source, e.Exception.InnerException, e.Exception.StackTrace, e.Exception.ToString()));
e.Handled = true;
}
void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
this.Dispatcher.BeginInvoke(DispatcherPriority.Send, new ThreadStart(delegate()
{
setUrl();
}));
}
private void setUrl()
{
ping = new Ping();
ping.PingCompleted += new PingCompletedEventHandler(ping_PingCompleted);
videoChecks checks = new videoChecks();
string ipAddressToUse = checks.isIPInternal(_camera.camIP) ? _camera.camIP : _camera.camExtIP;
ping.SendAsync(ipAddressToUse, 1000, null);
}
void ping_PingCompleted(object sender, PingCompletedEventArgs e)
{
try
{
if (e.Reply.Status == IPStatus.Success)
{
if (_successState == null || _successState == false)
{
_successState = true;
string uriWithResolution = string.Format("{0}&res={1}x{2}&header=0", _uri, (int)_width, (int)_height);
if (Frame1 != null)
Frame1.Source = new Uri(uriWithResolution);
}
}
else
{
if (_successState == null || _successState == true)
{
_successState = false;
Image1.Source = new BitmapImage(new Uri(_noImageUrl));
}
}
}
catch (ObjectDisposedException ex)
{
Dispose();
}
finally
{
((IDisposable)sender).Dispose();
}
}
#region IDisposable Members
public void Dispose()
{
if (timer != null)
{
timer.Elapsed -= new System.Timers.ElapsedEventHandler(timer_Elapsed);
timer.Enabled = false;
timer.Dispose();
timer = null;
}
Frame1.Source = null;
if (ping != null)
{
ping.PingCompleted -= new PingCompletedEventHandler(ping_PingCompleted);
((IDisposable)ping).Dispose();
ping = null;
}
}
#endregion
}
推荐答案
如果您查看堆栈跟踪底部的故障模块，则会看到msvfw32.dll。这不是WPF使用的DLL，因此我假设它来自您正在加载的网页中的一些active-x。我更相信这一点，因为您的代码隐含了处理摄像头/视频的问题，而msvfw32处理视频（它也很老！）。它显示在Dispatcher循环中，因为Dispatcher还会处理Win32消息循环，该循环最终由所谓的Activex使用。
If you look at the faulting module at the bottom your stacktrace, you will see msvfw32.dll. This is not a DLL used by WPF, so I assume it's coming from some active-x within a web page you are loading. I'm even more convinced of that due to your code implying something dealing with cameras/video and msvfw32 deals with video (its very old too!!). It's showing up in the Dispatcher loop because the Dispatcher also handles a Win32 message loop, that is ultimately used by the alleged activex.
也请尝试检查此处例外，也许您可以设置参数Handled = true
Also, try checking for the exception here, maybe you can set the argument Handled=true
这篇关于跟踪WPF中的AccessViolationException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
