将字节数组转换为对象

C# 有没有办法将纯字节数组转换为对象？

例如给定这个类：

class Data
{
    public int _int1;
    public int _int2;
    public short _short1;
    public long _long1;
}

我希望基本上能够做这样的事情：

var bytes = new byte[] { 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 4, 0, 0, 0, 0, 0, 0, 0 };
var obj = (Data)bytes;

您可以尝试编组：

将类的布局声明为顺序（并注意，您将需要使用Pack = 1):

[StructLayout(LayoutKind.Sequential, Pack = 1)]
class Data
{
    public int _int1;
    public int _int2;
    public short _short1;
    public long _long1;
}

将字节编组到 Data 类的新实例中：

var bytes = new byte[] { 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 4, 0, 0, 0, 0, 0, 0, 0 };
GCHandle gcHandle = GCHandle.Alloc(bytes, GCHandleType.Pinned);
var data = (Data)Marshal.PtrToStructure(gcHandle.AddrOfPinnedObject(), typeof(Data));
gcHandle.Free();

// Now data should contain the correct values.

Console.WriteLine(data._int1);    // Prints 1
Console.WriteLine(data._int2);    // Prints 2
Console.WriteLine(data._short1);  // Prints 3
Console.WriteLine(data._long1);   // Prints 4

为了方便起见，您可以在 Data 上编写一个静态方法来进行转换：

[StructLayout(LayoutKind.Sequential, Pack = 1)]
class Data
{
    public int _int1;
    public int _int2;
    public short _short1;
    public long _long1;

    public static Data FromBytes(byte[] bytes)
    {
        GCHandle gcHandle = GCHandle.Alloc(bytes, GCHandleType.Pinned);
        var data = (Data)Marshal.PtrToStructure(gcHandle.AddrOfPinnedObject(), typeof(Data));
        gcHandle.Free();
        return data;
    }
}

...

var data = Data.FromBytes(new byte[] {1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 4, 0, 0, 0, 0, 0, 0, 0});

如果您确实愿意，可以编写一个显式运算符来从字节数组进行转换，以获取 OP 中的语法。我建议只使用Data.FromBytes()在我看来，这会更加清晰。

不过，为了完整性：

[StructLayout(LayoutKind.Sequential, Pack = 1)]
class Data
{
    public int _int1;
    public int _int2;
    public short _short1;
    public long _long1;

    public static explicit operator Data(byte[] bytes)
    { 
        GCHandle gcHandle = GCHandle.Alloc(bytes, GCHandleType.Pinned);
        var data = (Data)Marshal.PtrToStructure(gcHandle.AddrOfPinnedObject(), typeof(Data));
        gcHandle.Free();
        return data;
    }
}

...

var data = (Data)new byte[] {1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 4, 0, 0, 0, 0, 0, 0, 0};