在Windows窗体（不是WPF）中，我希望使用ListBox来设置颜色编码的日志窗口，如果文本太长，则条目会回滚。
以下代码有效（从this answer复制），但条目不会换行，如果它们太长则会被截断。我怎么能修改这段代码，以便日志条目包装？
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Threading;
using System.Text;
namespace StackOverflow
{
public partial class Main : Form
{
public static ListBoxLog listBoxLog;
public Main()
{
InitializeComponent();
listBoxLog = new ListBoxLog(listBox1);
Thread thread = new Thread(LogStuffThread);
thread.IsBackground = true;
thread.Start();
}
private void LogStuffThread()
{
int number = 0;
while (true)
{
listBoxLog.Log(Level.Info, "A info level message from thread # {0,0000}", number++);
Thread.Sleep(2000);
}
}
private void button1_Click(object sender, EventArgs e)
{
listBoxLog.Log(Level.Debug, "A debug level message");
}
private void button2_Click(object sender, EventArgs e)
{
listBoxLog.Log(Level.Verbose, "A verbose level message");
}
private void button3_Click(object sender, EventArgs e)
{
listBoxLog.Log(Level.Info, "A info level message");
}
private void button4_Click(object sender, EventArgs e)
{
listBoxLog.Log(Level.Warning, "A warning level message");
}
private void button5_Click(object sender, EventArgs e)
{
listBoxLog.Log(Level.Error, "A very very very very very very very very very very very loooooooooooooong error level message");
}
private void button6_Click(object sender, EventArgs e)
{
listBoxLog.Log(Level.Critical, "A critical level message");
}
private void button7_Click(object sender, EventArgs e)
{
listBoxLog.Paused = !listBoxLog.Paused;
}
}
public enum Level : int
{
Critical = 0,
Error = 1,
Warning = 2,
Info = 3,
Verbose = 4,
Debug = 5
};
public sealed class ListBoxLog : IDisposable
{
private const string DEFAULT_MESSAGE_FORMAT = "{0} [{5}] : {8}";
private const int DEFAULT_MAX_LINES_IN_LISTBOX = 2000;
private bool _disposed;
private ListBox _listBox;
private string _messageFormat;
private int _maxEntriesInListBox;
private bool _canAdd;
private bool _paused;
private void OnHandleCreated(object sender, EventArgs e)
{
_canAdd = true;
}
private void OnHandleDestroyed(object sender, EventArgs e)
{
_canAdd = false;
}
private void DrawItemHandler(object sender, DrawItemEventArgs e)
{
if (e.Index >= 0)
{
e.DrawBackground();
e.DrawFocusRectangle();
LogEvent logEvent = ((ListBox)sender).Items[e.Index] as LogEvent;
// SafeGuard against wrong configuration of list box
if (logEvent == null)
{
logEvent = new LogEvent(Level.Critical, ((ListBox)sender).Items[e.Index].ToString());
}
Color color;
switch (logEvent.Level)
{
case Level.Critical:
color = Color.White;
break;
case Level.Error:
color = Color.Red;
break;
case Level.Warning:
color = Color.Goldenrod;
break;
case Level.Info:
color = Color.Green;
break;
case Level.Verbose:
color = Color.Blue;
break;
default:
color = Color.Black;
break;
}
if (logEvent.Level == Level.Critical)
{
e.Graphics.FillRectangle(new SolidBrush(Color.Red), e.Bounds);
}
e.Graphics.DrawString(FormatALogEventMessage(logEvent, _messageFormat), new Font("Lucida Console", 8.25f, FontStyle.Regular), new SolidBrush(color), e.Bounds);
}
}
private void KeyDownHandler(object sender, KeyEventArgs e)
{
if ((e.Modifiers == Keys.Control) && (e.KeyCode == Keys.C))
{
CopyToClipboard();
}
}
private void CopyMenuOnClickHandler(object sender, EventArgs e)
{
CopyToClipboard();
}
private void CopyMenuPopupHandler(object sender, EventArgs e)
{
ContextMenu menu = sender as ContextMenu;
if (menu != null)
{
menu.MenuItems[0].Enabled = (_listBox.SelectedItems.Count > 0);
}
}
private class LogEvent
{
public LogEvent(Level level, string message)
{
EventTime = DateTime.Now;
Level = level;
Message = message;
}
public readonly DateTime EventTime;
public readonly Level Level;
public readonly string Message;
}
private void WriteEvent(LogEvent logEvent)
{
if ((logEvent != null) && (_canAdd))
{
_listBox.BeginInvoke(new AddALogEntryDelegate(AddALogEntry), logEvent);
}
}
private delegate void AddALogEntryDelegate(object item);
private void AddALogEntry(object item)
{
_listBox.Items.Add(item);
if (_listBox.Items.Count > _maxEntriesInListBox)
{
_listBox.Items.RemoveAt(0);
}
if (!_paused) _listBox.TopIndex = _listBox.Items.Count - 1;
}
private string LevelName(Level level)
{
switch (level)
{
case Level.Critical: return "Critical";
case Level.Error: return "Error";
case Level.Warning: return "Warning";
case Level.Info: return "Info";
case Level.Verbose: return "Verbose";
case Level.Debug: return "Debug";
default: return string.Format("<value={0}>", (int)level);
}
}
private string FormatALogEventMessage(LogEvent logEvent, string messageFormat)
{
string message = logEvent.Message;
if (message == null) { message = "<NULL>"; }
return string.Format(messageFormat,
/* {0} */ logEvent.EventTime.ToString("yyyy-MM-dd HH:mm:ss.fff"),
/* {1} */ logEvent.EventTime.ToString("yyyy-MM-dd HH:mm:ss"),
/* {2} */ logEvent.EventTime.ToString("yyyy-MM-dd"),
/* {3} */ logEvent.EventTime.ToString("HH:mm:ss.fff"),
/* {4} */ logEvent.EventTime.ToString("HH:mm:ss"),
/* {5} */ LevelName(logEvent.Level)[0],
/* {6} */ LevelName(logEvent.Level),
/* {7} */ (int)logEvent.Level,
/* {8} */ message);
}
private void CopyToClipboard()
{
if (_listBox.SelectedItems.Count > 0)
{
StringBuilder selectedItemsAsRTFText = new StringBuilder();
selectedItemsAsRTFText.AppendLine(@"{\rtf1\ansi\deff0{\fonttbl{\f0\fcharset0 Courier;}}");
selectedItemsAsRTFText.AppendLine(@"{\colortbl;\red255\green255\blue255;\red255\green0\blue0;\red218\green165\blue32;\red0\green128\blue0;\red0\green0\blue255;\red0\green0\blue0}");
foreach (LogEvent logEvent in _listBox.SelectedItems)
{
selectedItemsAsRTFText.AppendFormat(@"{{\f0\fs16\chshdng0\chcbpat{0}\cb{0}\cf{1} ", (logEvent.Level == Level.Critical) ? 2 : 1, (logEvent.Level == Level.Critical) ? 1 : ((int)logEvent.Level > 5) ? 6 : ((int)logEvent.Level) + 1);
selectedItemsAsRTFText.Append(FormatALogEventMessage(logEvent, _messageFormat));
selectedItemsAsRTFText.AppendLine(@"\par}");
}
selectedItemsAsRTFText.AppendLine(@"}");
System.Diagnostics.Debug.WriteLine(selectedItemsAsRTFText.ToString());
Clipboard.SetData(DataFormats.Rtf, selectedItemsAsRTFText.ToString());
}
}
public ListBoxLog(ListBox listBox) : this(listBox, DEFAULT_MESSAGE_FORMAT, DEFAULT_MAX_LINES_IN_LISTBOX) { }
public ListBoxLog(ListBox listBox, string messageFormat) : this(listBox, messageFormat, DEFAULT_MAX_LINES_IN_LISTBOX) { }
public ListBoxLog(ListBox listBox, string messageFormat, int maxLinesInListbox)
{
_disposed = false;
_listBox = listBox;
_messageFormat = messageFormat;
_maxEntriesInListBox = maxLinesInListbox;
_paused = false;
_canAdd = listBox.IsHandleCreated;
_listBox.SelectionMode = SelectionMode.MultiExtended;
_listBox.HandleCreated += OnHandleCreated;
_listBox.HandleDestroyed += OnHandleDestroyed;
_listBox.DrawItem += DrawItemHandler;
_listBox.KeyDown += KeyDownHandler;
MenuItem[] menuItems = new MenuItem[] { new MenuItem("Copy", new EventHandler(CopyMenuOnClickHandler)) };
_listBox.ContextMenu = new ContextMenu(menuItems);
_listBox.ContextMenu.Popup += new EventHandler(CopyMenuPopupHandler);
_listBox.DrawMode = DrawMode.OwnerDrawFixed;
}
public void Log(string message) { Log(Level.Debug, message); }
public void Log(string format, params object[] args) { Log(Level.Debug, (format == null) ? null : string.Format(format, args)); }
public void Log(Level level, string format, params object[] args) { Log(level, (format == null) ? null : string.Format(format, args)); }
public void Log(Level level, string message)
{
WriteEvent(new LogEvent(level, message));
}
public bool Paused
{
get { return _paused; }
set { _paused = value; }
}
~ListBoxLog()
{
if (!_disposed)
{
Dispose(false);
_disposed = true;
}
}
public void Dispose()
{
if (!_disposed)
{
Dispose(true);
GC.SuppressFinalize(this);
_disposed = true;
}
}
private void Dispose(bool disposing)
{
if (_listBox != null)
{
_canAdd = false;
_listBox.HandleCreated -= OnHandleCreated;
_listBox.HandleCreated -= OnHandleDestroyed;
_listBox.DrawItem -= DrawItemHandler;
_listBox.KeyDown -= KeyDownHandler;
_listBox.ContextMenu.MenuItems.Clear();
_listBox.ContextMenu.Popup -= CopyMenuPopupHandler;
_listBox.ContextMenu = null;
_listBox.Items.Clear();
_listBox.DrawMode = DrawMode.Normal;
_listBox = null;
}
}
}
}