我编写了一个WPF应用程序，它使用许多Frame控件来查看摄像头源。部署后，它会随机崩溃（从2小时到16小时不等），我会在事件日志中连续看到这些：
System.AccessViolationException： 试图读或写受保护 记忆。这通常是一个迹象 其他内存已损坏。在 MS.Win32.UnsafeNativeMethods.DispatchMessage（MSG＆安培; msg）at System.Windows.Threading.Dispatcher.PushFrameImpl（DispatcherFrame 框架） System.Windows.Threading.Dispatcher.PushFrame（DispatcherFrame 框架） System.Windows.Threading.Dispatcher.Run（） 在 System.Windows.Application.RunDispatcher（对象 忽略） System.Windows.Application.RunInternal（窗口 窗口） System.Windows.Application.Run（窗口 窗口） System.Windows.Application.Run（）at Status_Station_client.MainClass.Main（）
故障应用程序状态站 client.exe，版本1.0.0.0，邮票 4ad0faa5，故障模块msvfw32.dll， 版本5.1.2600.2180，邮票41109753， 调试？ 0，故障地址0x00002642。
有关如何追踪此问题的任何想法？网页确实包含ActiveX控件，因此首先猜测那里存在问题。
我无法在调试模式下跟踪此信息。我想到的另一件事就是吞下导航电话中的异常，但我不确定这是否是明智之举：
try
{
if (Frame1 != null)
Frame1.Source = new Uri(uriWithResolution);
}
catch (AccessViolationException ex)
{
// log message
}
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：
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
}
答案 0 :(得分：5)
如果查看堆栈跟踪底部的错误模块，您将看到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某些active-x。我更加确信这是因为你的代码暗示处理相机/视频的东西和msvfw32处理视频（它太老了!!）。它出现在Dispatcher循环中，因为Dispatcher还处理Win32消息循环，最终由所谓的activex使用。
另外，尝试检查exception here，也许你可以设置参数Handled = true