Windows ICO 格式编码器

src/BD.WTTS.Client/Helpers/IcoEncoder.cs

+using SkiaSharp;
+
+// ReSharper disable once CheckNamespace
+namespace BD.WTTS;
+
+/// <summary>
+/// Windows ICO 格式编码器
+/// </summary>
+public static class IcoEncoder
+{
+    public static void Encode(Stream stream, IReadOnlyList<SKBitmap> bitmaps)
+    {
+        // 写入文件头
+        stream.WriteByte(0);
+        stream.WriteByte(0);
+        stream.WriteByte(1); // 1 为图标，2 为光标
+        stream.WriteByte(0);
+
+        // 写入长度，2 位
+        stream.Write(BitConverter.GetBytes(Convert.ToInt16(bitmaps.Count)));
+
+        Class253 class253_1;
+        List<Class253> class253List = new();
+        List<MemoryStream> memoryStreamList = new();
+        for (int index = 0; index < bitmaps.Count; ++index)
+        {
+            var image = bitmaps[index];
+            MemoryStream memoryStream1 = new();
+            image.Encode(memoryStream1, SKEncodedImageFormat.Png, 100);
+            int num1 = (int)memoryStream1.Length;
+            memoryStreamList.Add(memoryStream1);
+            class253_1 = new(image.Width, image.Height, 0, image.BytesPerPixel);
+            class253_1.method_14(num1);
+            Class253 class253_2 = class253_1;
+            class253List.Add(class253_2);
+        }
+        Dictionary<Class253, MemoryStream> dictionary_0 = new();
+        for (int index = 0; index < memoryStreamList.Count; ++index)
+            dictionary_0.Add(class253List[index], memoryStreamList[index]);
+
+        smethod_6(dictionary_0);
+
+        smethod_21(stream, dictionary_0);
+    }
+
+    // it's just works
+
+#pragma warning disable IDE1006 // 命名样式
+
+    static void smethod_6(Dictionary<Class253, MemoryStream> dictionary_0)
+    {
+        var class253List = dictionary_0.Keys.ToArray();
+        Class253 class253_1 = class253List[0];
+        class253_1.method_16(6 + (16 * dictionary_0.Count));
+        int int_0 = class253_1.method_15() + class253_1.method_13();
+        for (int index = 1; index < class253List.Length; ++index)
+        {
+            Class253 class253_2 = class253List[index];
+            class253_2.method_16(int_0);
+            int_0 += class253_2.method_13();
+        }
+    }
+
+    sealed class Class253
+    {
+        byte[] byte_0 = null!;
+
+        public Class253(int int_0, int int_1, int int_2, int int_3, int int_4, int int_5)
+        {
+            List<byte> byteList = new List<byte>()
+            {
+                (byte)int_0,
+                (byte)int_1,
+                int_3 <= 8 ? (byte)int_2 : (byte)0,
+                0,
+            };
+            byteList.AddRange(BitConverter.GetBytes((short)0));
+            byteList.AddRange(BitConverter.GetBytes((short)int_3));
+            byteList.AddRange(BitConverter.GetBytes(int_4));
+            byteList.AddRange(BitConverter.GetBytes(int_5));
+            method_1(byteList.ToArray());
+        }
+
+        public Class253(int int_0, int int_1, int int_2, int int_3)
+          : this(int_0, int_1, int_2, int_3, 0, 0)
+        {
+        }
+
+        public byte[] method_0() => byte_0;
+
+        private void method_1(byte[] byte_1) => byte_0 = byte_1;
+
+        public int method_13() => BitConverter.ToInt32(method_0(), 8);
+
+        public void method_14(int int_0) => BitConverter.GetBytes(int_0).CopyTo(method_0(), 8);
+
+        public int method_15() => BitConverter.ToInt32(method_0(), 12);
+
+        public void method_16(int int_0) => BitConverter.GetBytes(int_0).CopyTo(method_0(), 12);
+    }
+
+    static void smethod_21(Stream stream_0, Dictionary<Class253, MemoryStream> dictionary_0)
+    {
+        smethod_6(dictionary_0);
+        foreach (Class253 key in dictionary_0.Keys)
+            stream_0.Write(key.method_0(), 0, 16);
+        foreach (MemoryStream memoryStream in dictionary_0.Values)
+        {
+            using (memoryStream)
+                memoryStream.WriteTo(stream_0);
+        }
+    }
+}

src/BD.WTTS.UnitTest/IcoTest.cs

+using SkiaSharp;
+
+namespace BD.WTTS.UnitTest;
+
+/// <summary>
+/// Windows ICO 格式测试
+/// </summary>
+public sealed class IcoTest
+{
+    /// <summary>
+    /// Windows ICO 格式编码测试
+    /// </summary>
+    [Test]
+    public void EncodeTest()
+    {
+        var logo512Path = Path.Combine(ProjectUtils.ProjPath, "res", "icons", "app", "v3", "Logo_512.png");
+        SKBitmap[]? logoBitmaps = null;
+        try
+        {
+            using var logo512Bitmap = SKBitmap.Decode(logo512Path);
+
+            logoBitmaps = new[] { logo512Bitmap }.Concat(new[] { 256, 128, 96, 64, 48, 32, 24, 16 }
+                .Select(x => logo512Bitmap.Resize(new SKSizeI { Height = x, Width = x }, SKFilterQuality.High)))
+                .ToArray(); // 根据 512 大小生成所有挡位的位图数组
+
+            var savePath = $"{logo512Path}.ico";
+            try
+            {
+                // 创建 ico 文件内存流
+                using var fs = new FileStream(
+                    savePath,
+                    FileMode.Create,
+                    FileAccess.ReadWrite,
+                    FileShare.ReadWrite | FileShare.Delete);
+                IcoEncoder.Encode(fs, logoBitmaps);
+                TestContext.WriteLine(savePath);
+            }
+            finally
+            {
+                // 删除生成的文件，清理
+                IOPath.FileTryDelete(savePath);
+            }
+        }
+        finally
+        {
+            if (logoBitmaps != null)
+            {
+                foreach (var logoBitmap in logoBitmaps)
+                {
+                    logoBitmap.Dispose();
+                }
+            }
+        }
+    }
+
+}