在我们的应用程序中，我们有一个跟踪窗口，我们可以在客户端位置启用以允许一些调试，它被认为是静态库。
问题是，当有大量日志消息进入窗口时，它会因AccessViolation错误而崩溃。崩溃的代码链接是RichTextBox.AppendText（..，..，..）。
这是我们创建窗口的地方。
public static void Start(Form parent)
{
if (_runningThread == null || !_runningThread.IsAlive)
{
_runningThread = new Thread(() =>
{
_traceView = new TraceView(parent) { Text = "Tracing ~ " + parent.Text };
Application.Run(_traceView);
});
_runningThread.SetApartmentState(ApartmentState.MTA);
_runningThread.Start();
}
}
这是我们在文本框中写一行
public void Write(string line, Color color)
{
try
{
_msgQueue.Enqueue(new Tuple<string, Color>(line, color));
MethodInvoker gui = delegate
{
try
{
// Was getting an overflow so trim out some lines
if (uiTrace.Lines.Length > 5000)
{
uiTrace.Lines = new string[0];
uiTrace.SelectionStart = uiTrace.TextLength;
Application.DoEvents();
}
while (_msgQueue.Count != 0)
{
bool retry;
var count = 0;
do
{
try
{
count++;
if (_indent < 0)
_indent = 0;
var msg = _msgQueue.Dequeue();
var selectionStart = uiTrace.TextLength;
uiTrace.AppendText(string.Format("[{0}] {1}{2}", _stopwatch.ElapsedMilliseconds, string.Empty.PadLeft(_indent * 4), msg.Item1));
uiTrace.Select(selectionStart, uiTrace.TextLength);
uiTrace.SelectionColor = msg.Item2;
uiTrace.SelectionStart = uiTrace.TextLength;
uiTrace.ScrollToCaret();
retry = false;
}
catch (Exception)
{
retry = true;
}
} while (retry && count < 5);
}
}
catch (Exception)
{
// We don't care about exceptions in here, for now anyway
}
};
if (uiTrace.InvokeRequired && !uiTrace.Disposing && !uiTrace.IsDisposed)
{
uiTrace.BeginInvoke(gui);
return;
}
gui();
}
catch (Exception)
{
// QIT_Backoffice.Processes.Errors.ErrorHandler.WriteErrorLog(Sources.SourceEnum.External, ex, "Error writing to trace");
}
}
我真的不知道如何解决这个问题，我认为调用BeginInvoke（）就是需要的。
寻找任何可能的帮助，或者如果有人知道可以更好地处理这个问题的第三方工具，我很高兴看到这一点。
答案 0 :(得分：0)
我对VB的体验比C＃更多。但是没有以下代码：
if (uiTrace.InvokeRequired && !uiTrace.Disposing && !uiTrace.IsDisposed)
{
uiTrace.BeginInvoke(gui);
return;
}
gui();
导致在gui语句中调用InvokeRequired等If，以及在{{当前（可能是非UI）线程中执行（再次）gui() 1}}。
岂不：
If (uiTrace.InvokeRequired && !uiTrace.Disposing && !uiTrace.IsDisposed)
{
uiTrace.BeginInvoke(gui);
return;
}
Else
gui();
更合适吗？
答案 1 :(得分：0)
以下是我对记录器的修改。请注意_processing和lock如何用于避免重入和保护_queue。此外，我使用SynchronizationContext而不是Control.BeginInvoke来避免对窗口处置状态的任何依赖。可以创建TraceView（使用TraceView.Create）并在任何线程中使用parent，但是它的窗口属于richedit窗口的线程，并且它也是将文本传递到_processing的位置。可以为此设置一个专用的STA线程，但我觉得没必要。
[已编辑] 我已经消除了检查CreateOnOwnThread时可能存在竞争条件的情况，并添加了Application.DoEvents()，以防需要记录器UI的专用线程。我还决定在紧急循环中调用Write的情况下保留private void Form1_Load(object sender, EventArgs ev)
{
var traceView = TraceView.Create(this);
for (var i = 0; i < 1000; i++)
{
var _i = i;
Task.Run(() =>
{
traceView.Write(String.Format("Line: {0}\n", _i), System.Drawing.Color.Green);
});
}
}
，以保持用户界面的响应。
用法（压力测试）：
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Logger
{
public partial class TraceView : Form
{
private Form _parent = null;
private SynchronizationContext _context = SynchronizationContext.Current;
private int _threadId = Thread.CurrentThread.ManagedThreadId;
private object _lock = new Object(); // sync lock to protect _queue and _processing
private Queue<Tuple<string, Color>> _queue = new Queue<Tuple<string, Color>>();
private volatile bool _processing = false; // reentracy check flag
public TraceView(Form parent)
{
_parent = parent;
InitializeComponent();
}
public static TraceView Create(Form parent)
{
TraceView view = null;
// create it on the parent window's thread
parent.Invoke(new Action(() => {
view = new TraceView(parent);
view.Show(parent);
}));
return view;
}
private void DequeueMessages()
{
// make sure we are on the UI thread
Debug.Assert(Thread.CurrentThread.ManagedThreadId == _threadId);
lock (_lock)
{
// prevent re-entracy
if (_processing)
return;
// mark the beginning of processing
_processing = true;
}
// process pending messages
for (; ; )
{
Tuple<string, Color> msg = null;
lock (_lock)
{
if (!_queue.Any())
{
// mark the end of processing
_processing = false;
return;
}
msg = _queue.Dequeue();
}
if (this.Disposing || this.IsDisposed)
{
// do not just loose messages if the window is disposed
Trace.Write(msg.Item1);
}
else
{
var selectionStart = _richTextBox.TextLength;
_richTextBox.AppendText(msg.Item1);
_richTextBox.Select(selectionStart, _richTextBox.TextLength);
_richTextBox.SelectionColor = msg.Item2;
_richTextBox.SelectionStart = _richTextBox.TextLength;
_richTextBox.ScrollToCaret();
_richTextBox.Refresh(); // redraw;
// DoEvents is required if logging from a tight loop,
// to keep the UI responsive
Application.DoEvents();
}
}
}
public void Write(string line, Color color)
{
lock (_lock)
{
_queue.Enqueue(new Tuple<string, Color>(line, color));
// prevent re-entracy
if (_processing)
return; // DequeueMessages is already in progress
}
if (Thread.CurrentThread.ManagedThreadId == _threadId)
DequeueMessages();
else
_context.Post((_) =>
{
DequeueMessages();
}, null);
}
public static TraceView CreateOnOwnThread()
{
TraceView view = null;
using (var sync = new ManualResetEventSlim())
{
// create it on its own thread
var thread = new Thread(() =>
{
SynchronizationContext.SetSynchronizationContext(new WindowsFormsSynchronizationContext());
view = new TraceView(null);
view.Show();
sync.Set(); // ready Write calls
Application.Run(view); // view does Application.ExitThread() when closed
return;
});
thread.SetApartmentState(ApartmentState.STA);
thread.Start();
sync.Wait();
}
return view;
}
}
}
实现：
{{1}}