font-preview/FontPreview/Worker.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Text;
using System.IO;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows.Forms;

namespace FontPreview;

public class Worker
{
	public class CardData
	{
		public Bitmap Bitmap;

		public int Width;

		public string Name;

		public string DisplayName;

		public string Path;

		public bool Failed;
	}

	public delegate void CompletedHandler(bool cancelled, int done, int failed, int remain, List<CardData> cards);

	private MainForm form;

	private List<FontItem> items;

	private int target;

	private string text;

	private int size;

	private Color fg;

	private Color bg;

	private Dictionary<string, Bitmap> cache;

	private Thread thread;

	private volatile bool stop;

	private List<CardData> results = new List<CardData>();

	public event CompletedHandler Completed;

	public Worker(MainForm f, List<FontItem> items, int target, string text, int size, Color fg, Color bg, Dictionary<string, Bitmap> cache)
	{
		form = f;
		this.items = items;
		this.target = target;
		this.text = text;
		this.size = size;
		this.fg = fg;
		this.bg = bg;
		this.cache = cache;
	}

	public bool IsRunning()
	{
		return thread != null && thread.IsAlive;
	}

	public void Stop()
	{
		stop = true;
	}

	public void Start()
	{
		stop = false;
		thread = new Thread(Run);
		thread.IsBackground = true;
		thread.SetApartmentState(ApartmentState.STA);
		thread.Start();
	}

	private void Run()
	{
		int total = target;
		int next = 0;
		int done = 0;
		int failed = 0;
		// 并行渲染：拉满 CPU 线程，批量并行
		int workers = Math.Max(2, Environment.ProcessorCount);
		object renderLock = new object();

		ParameterizedThreadStart work = delegate (object _)
		{
			while (true)
			{
				if (stop) break;
				int i = Interlocked.Increment(ref next) - 1;
				if (i >= total) break;
				FontItem fontItem = items[i];
				Bitmap value = null;
				bool failed2 = false;
				string key = fontItem.Cat + "|" + fontItem.Path;
				lock (renderLock) { cache.TryGetValue(key, out value); }
				if (value == null)
				{
					value = RenderFont(fontItem.Path, fontItem.Name, text, size, fg, bg, out failed2);
					if (value != null)
					{
						lock (renderLock) { cache[key] = value; }
					}
				}
				CardData cardData = new CardData();
				cardData.Bitmap = value;
				cardData.Width = 340;
				cardData.Name = fontItem.Name;
				cardData.DisplayName = fontItem.DisplayName;
				cardData.Path = fontItem.Path;
				cardData.Failed = failed2;
				lock (results) { results.Add(cardData); }
				int d = Interlocked.Increment(ref done);
				if (value == null) Interlocked.Increment(ref failed);
				// 进度更新节流：每 10 个或最后一个才唤醒 UI，避免频繁打断
				if (d % 10 == 0 || d >= total)
				{
					int pct = (int)((double)d / (double)total * 100.0);
					((Control)form).BeginInvoke((Delegate)(Action)delegate
					{
						form.SetProgress(pct, d, total);
					});
				}
			}
		};

		Thread[] ts = new Thread[workers];
		for (int w = 0; w < workers; w++)
		{
			ts[w] = new Thread(work);
			ts[w].IsBackground = true;
			ts[w].Start();
		}
		foreach (Thread wt in ts) wt.Join();

		int remain = total - done;
		List<CardData> snapshot;
		lock (results) { snapshot = new List<CardData>(results); }
		((Control)form).Invoke((Delegate)(Action)delegate
		{
			if (this.Completed != null)
			{
				this.Completed(stop, done, failed, remain, snapshot);
			}
		});
	}

	internal static Bitmap RenderFont(string path, string name, string text, int size, Color fg, Color bg, out bool failed)
	{
		//IL_0026: Unknown result type (might be due to invalid IL or missing references)
		//IL_002c: Expected O, but got Unknown
		//IL_006e: Unknown result type (might be due to invalid IL or missing references)
		//IL_0074: Expected O, but got Unknown
		//IL_0089: Unknown result type (might be due to invalid IL or missing references)
		//IL_0090: Expected O, but got Unknown
		//IL_00e8: Unknown result type (might be due to invalid IL or missing references)
		//IL_00ee: Expected O, but got Unknown
		//IL_0115: Unknown result type (might be due to invalid IL or missing references)
		//IL_011c: Expected O, but got Unknown
		failed = false;
		Bitmap val = null;
		PrivateFontCollection val2 = null;
		Font val3 = null;
		try
		{
			// 直接按文件路径加载，避免 AddMemoryFont 在快速连续渲染多字体时按内存地址缓存导致串字体
			val2 = new PrivateFontCollection();
			val2.AddFontFile(path);
			if (((FontCollection)val2).Families.Length == 0)
			{
				failed = true;
				return null;
			}
			FontFamily val4 = ((FontCollection)val2).Families[0];
			val3 = new Font(val4, (float)size, (FontStyle)0, (GraphicsUnit)2);
			int num = 14;
			Graphics val5 = Graphics.FromHwnd(IntPtr.Zero);
			try
			{
				StringFormat val6 = new StringFormat((StringFormatFlags)4096);
				try
				{
					val6.Alignment = (StringAlignment)0;
					val6.LineAlignment = (StringAlignment)1;
					SizeF sizeF = val5.MeasureString(text, val3, 20000, val6);
					int num2 = (int)Math.Ceiling(sizeF.Width) + num * 2;
					int num3 = (int)Math.Ceiling(sizeF.Height) + 14;
					val = new Bitmap(num2, Math.Max(num3, 30));
					Graphics val7 = Graphics.FromImage((Image)(object)val);
					try
					{
						val7.SmoothingMode = (SmoothingMode)4;
						val7.TextRenderingHint = (TextRenderingHint)4;
						val7.Clear(bg);
						Brush val8 = (Brush)new SolidBrush(fg);
						try
						{
							val7.DrawString(text, val3, val8, new RectangleF(num, 7f, sizeF.Width, num3 - 14), val6);
						}
						finally
						{
							((IDisposable)val8)?.Dispose();
						}
					}
					finally
					{
						((IDisposable)val7)?.Dispose();
					}
				}
				finally
				{
					((IDisposable)val6)?.Dispose();
				}
			}
			finally
			{
				((IDisposable)val5)?.Dispose();
			}
			return val;
		}
		catch (Exception)
		{
			failed = true;
			if (val != null)
			{
				((Image)val).Dispose();
			}
			return null;
		}
		finally
		{
			if (val3 != null)
			{
				val3.Dispose();
			}
			if (val2 != null)
			{
				((FontCollection)val2).Dispose();
			}
		}
	}
}