WinForms C#中的优雅日志窗口

Question

我正在寻找一种有效的方法来实现Windows窗体应用程序的日志窗口.在过去,我已经使用TextBox和RichTextBox实现了几个,但我仍然不完全满意这个功能.

此日志旨在向用户提供各种事件的近期历史记录,主要用于数据收集应用程序,其中可能会对特定事务的完成方式感到好奇.在这种情况下,日志不必是永久性的,也不必保存到文件中.

首先,一些提出的要求:

• 高效快速; 如果快速连续地将数百行写入日志,则需要消耗最少的资源和时间.
• 能够提供最多2000行左右的可变回滚.更长的时间是不必要的.
• 突出和颜色是首选.不需要字体效果.
• 达到回滚限制时自动修剪线条.
• 添加新数据时自动滚动.
• 奖励但不是必需的:在手动交互期间暂停自动滚动,例如用户正在浏览历史记录.

到目前为止我一直用来编写和修剪日志:

我使用以下代码(我从其他线程调用):

// rtbLog is a RichTextBox
// _MaxLines is an int
public void AppendLog(string s, Color c, bool bNewLine)
{
    if (rtbLog.InvokeRequired)
    {
        object[] args = { s, c, bNewLine };
        rtbLog.Invoke(new AppendLogDel(AppendLog), args);
        return;
    }
    try
    {
        rtbLog.SelectionColor = c;
        rtbLog.AppendText(s);
        if (bNewLine) rtbLog.AppendText(Environment.NewLine);
        TrimLog();
        rtbLog.SelectionStart = rtbLog.TextLength;
        rtbLog.ScrollToCaret();
        rtbLog.Update();
    }
    catch (Exception exc)
    {
        // exception handling
    }
}

private void TrimLog()
{
    try
    {
        // Extra lines as buffer to save time
        if (rtbLog.Lines.Length < _MaxLines + 10)
        {
            return;
        }
        else
        {
            string[] sTemp = rtxtLog.Lines;
            string[] sNew= new string[_MaxLines];
            int iLineOffset = sTemp.Length - _MaxLines;
            for (int n = 0; n < _MaxLines; n++)
            {
                sNew[n] = sTemp[iLineOffset];
                iLineOffset++;
            }
            rtbLog.Lines = sNew;
        }
    }
    catch (Exception exc)
    {
        // exception handling
    }
}

这种方法的问题是每当调用TrimLog时,我都会丢失颜色格式.使用常规TextBox,这很好用(当然有一点修改).

寻找解决方案从未真正令人满意.有人建议在RichTextBox中按字符数而不是行计数来修剪多余的部分.我也看过使用ListBoxes,但还没有成功尝试过.

Answer 1

我建议您根本不使用控件作为日志.而是编写一个具有所需属性的日志集合类(不包括显示属性).

然后编写将该集合转储到各种用户界面元素所需的一些代码.就个人而言,我会将SendToEditControl和SendToListBox方法放入我的日志对象中.我可能会为这些方法添加过滤功能.

您可以只在有意义的情况下更新UI日志,为您提供最佳性能,更重要的是,让您在日志快速变化时减少UI开销.

重要的是不要将您的日志记录绑定到UI,这是一个错误.总有一天,你可能想要无头跑.

从长远来看,记录器的良好UI可能是一个自定义控件.但从短期来看,您只想将日志记录与任何特定的UI 断开连接.

Answer 2

基于我前一段时间写的更复杂的记录器,我把这些东西扔在了一起.

这将支持基于日志级别的列表框中的颜色,支持Ctrl + V和右键单击以作为RTF进行复制,并处理从其他线程到ListBox的日志记录.

您可以使用其中一个构造函数重载覆盖ListBox中保留的行数(默认为2000)以及消息格式.

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 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;
            }
        }
    }
}

Answer 3

当我想使用RichTextBox再次记录彩色线条时,我会将此存储为Future Me的帮助.以下代码删除RichTextBox中的第一行:

if ( logTextBox.Lines.Length > MAX_LINES )
{
  logTextBox.Select(0, logTextBox.Text.IndexOf('\n')+1);
  logTextBox.SelectedRtf = "{\\rtf1\\ansi\\ansicpg1252\\deff0\\deflang1053\\uc1 }";
}

我花了太长时间才弄清楚将SelectedRtf设置为""不起作用,但将其设置为"正确"的RTF没有文本内容是可以的.

Answer 4

我创建基本日志窗口的解决方案与John Knoeller在他的回答中建议的完全一样。避免将日志信息直接存储在 TextBox 或 RichTextBox 控件中，而是创建一个可用于填充控件或写入文件等的日志记录类。

这个示例解决方案有几个部分：

1. 日志类本身，Logger.
2. 修改 RichTextBox 控件以在更新后添加滚动到底部功能；ScrollingRichTextBox.
3. 演示其使用的主要形式，LoggerExample.

首先，日志类：

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;

namespace Logger
{
    /// <summary>
    /// A circular buffer style logging class which stores N items for display in a Rich Text Box.
    /// </summary>
    public class Logger
    {
        private readonly Queue<LogEntry> _log;
        private uint _entryNumber;
        private readonly uint _maxEntries;
        private readonly object _logLock = new object();
        private readonly Color _defaultColor = Color.White;

        private class LogEntry
        {
            public uint EntryId;
            public DateTime EntryTimeStamp;
            public string EntryText;
            public Color EntryColor;
        }

        private struct ColorTableItem
        {
            public uint Index;
            public string RichColor;
        }

        /// <summary>
        /// Create an instance of the Logger class which stores <paramref name="maximumEntries"/> log entries.
        /// </summary>
        public Logger(uint maximumEntries)
        {
            _log = new Queue<LogEntry>();
            _maxEntries = maximumEntries;
        }

        /// <summary>
        /// Retrieve the contents of the log as rich text, suitable for populating a <see cref="System.Windows.Forms.RichTextBox.Rtf"/> property.
        /// </summary>
        /// <param name="includeEntryNumbers">Option to prepend line numbers to each entry.</param>
        public string GetLogAsRichText(bool includeEntryNumbers)
        {
            lock (_logLock)
            {
                var sb = new StringBuilder();

                var uniqueColors = BuildRichTextColorTable();
                sb.AppendLine($@"{{\rtf1{{\colortbl;{ string.Join("", uniqueColors.Select(d => d.Value.RichColor)) }}}");

                foreach (var entry in _log)
                {
                    if (includeEntryNumbers)
                        sb.Append($"\\cf1 { entry.EntryId }. ");

                    sb.Append($"\\cf1 { entry.EntryTimeStamp.ToShortDateString() } { entry.EntryTimeStamp.ToShortTimeString() }: ");

                    var richColor = $"\\cf{ uniqueColors[entry.EntryColor].Index + 1 }";
                    sb.Append($"{ richColor } { entry.EntryText }\\par").AppendLine();
                }
                return sb.ToString();
            }
        }

        /// <summary>
        /// Adds <paramref name="text"/> as a log entry.
        /// </summary>
        public void AddToLog(string text)
        {
            AddToLog(text, _defaultColor);
        }

        /// <summary>
        /// Adds <paramref name="text"/> as a log entry, and specifies a color to display it in.
        /// </summary>
        public void AddToLog(string text, Color entryColor)
        {
            lock (_logLock)
            {
                if (_entryNumber >= uint.MaxValue)
                    _entryNumber = 0;
                _entryNumber++;
                var logEntry = new LogEntry { EntryId = _entryNumber, EntryTimeStamp = DateTime.Now, EntryText = text, EntryColor = entryColor };
                _log.Enqueue(logEntry);

                while (_log.Count > _maxEntries)
                    _log.Dequeue();
            }
        }

        /// <summary>
        /// Clears the entire log.
        /// </summary>
        public void Clear()
        {
            lock (_logLock)
            {
                _log.Clear();
            }
        }

        private Dictionary<Color, ColorTableItem> BuildRichTextColorTable()
        {
            var uniqueColors = new Dictionary<Color, ColorTableItem>();
            var index = 0u;

            uniqueColors.Add(_defaultColor, new ColorTableItem() { Index = index++, RichColor = ColorToRichColorString(_defaultColor) });

            foreach (var c in _log.Select(l => l.EntryColor).Distinct().Where(c => c != _defaultColor))
                uniqueColors.Add(c, new ColorTableItem() { Index = index++, RichColor = ColorToRichColorString(c) });

            return uniqueColors;
        }

        private string ColorToRichColorString(Color c)
        {
            return $"\\red{c.R}\\green{c.G}\\blue{c.B};";
        }
    }
}

Logger 类包含另一个类LogEntry，它跟踪行号、时间戳和所需的颜色。结构体用于构建富文本颜色表。

接下来，这里是修改后的 RichTextBox：

using System;
using System.Runtime.InteropServices;

namespace Logger
{
    public class ScrollingRichTextBox : System.Windows.Forms.RichTextBox
    {
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr SendMessage(
            IntPtr hWnd,
            uint Msg,
            IntPtr wParam,
            IntPtr LParam);

        private const int _WM_VSCROLL = 277;
        private const int _SB_BOTTOM = 7;

        /// <summary>
        /// Scrolls to the bottom of the RichTextBox.
        /// </summary>
        public void ScrollToBottom()
        {
            SendMessage(Handle, _WM_VSCROLL, new IntPtr(_SB_BOTTOM), new IntPtr(0));
        }
    }
}

我在这里所做的只是继承一个 RichTextBox 并添加一个“滚动到底部”的方法。关于如何在 StackOverflow 上执行此操作还有各种其他问题，我从中得出了这种方法。

最后，从表单中使用此类的示例：

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace Logger
{
    public partial class LoggerExample : Form
    {
        private Logger _log = new Logger(100u);
        private List<Color> _randomColors = new List<Color> { Color.Red, Color.SkyBlue, Color.Green };
        private Random _r = new Random((int)DateTime.Now.Ticks);

        public LoggerExample()
        {
            InitializeComponent();
        }

        private void timerGenerateText_Tick(object sender, EventArgs e)
        {
            if (_r.Next(10) > 5)
                _log.AddToLog("Some event to log.", _randomColors[_r.Next(3)]);
        }

        private void timeUpdateLogWindow_Tick(object sender, EventArgs e)
        {
            richTextBox1.Rtf = _log.GetLogAsRichText(true);
            richTextBox1.ScrollToBottom();
        }
    }
}

此表单由两个计时器创建，一个用于伪随机生成日志条目，另一个用于填充 RichTextBox 本身。在此示例中，日志类使用 100 行回滚进行实例化。RichTextBox 控件颜色设置为黑色背景，白色和各种颜色的前景。生成文本的计时器间隔为 100 毫秒，而更新日志窗口的计时器间隔为 1000 毫秒。

示例输出：

它远非完美或完成，但这里有一些注意事项和可以添加或改进的东西（其中一些我在以后的项目中做过）：

1. 的值较大时maximumEntries，性能较差。这个日志类只是为几百行回滚而设计的。
2. 替换 RichTextBox 的文本会导致闪烁。我总是将刷新计时器保持在相对较慢的间隔。（本例中为一秒。）
3. 添加到上面的#2，我的一些项目在重绘 RichTextBox 内容之前检查日志是否有任何新条目，以避免不必要地刷新它。
4. 每个日志条目上的时间戳可以是可选的，并允许使用不同的格式。
5. 在这个例子中没有办法暂停日志，但我的许多项目确实提供了一种暂停滚动行为的机制，允许用户从日志窗口手动滚动、选择和复制文本。

随意修改和改进这个例子。欢迎反馈。

Answer 5

我会说ListView非常适合此操作（在“详细信息”查看模式下），而这正是我在一些内部应用程序中使用的功能。

有用的提示：如果您知道一次要添加/删除很多项目，请使用BeginUpdate（）和EndUpdate（）。

Answer 6

我最近实现了类似的东西.我们的方法是保留回滚记录的环形缓冲区,并手动绘制日志文本(使用Graphics.DrawString).然后,如果用户想要向后滚动,复制文本等,我们有一个"暂停"按钮,可以翻转回普通的TextBox控件.