如何在C＃中将值类型转换为byte []？

I want to do the equivalent of this:

我想做相当于这个：

byte[] byteArray;
enum commands : byte {one, two};
commands content = one;
byteArray = (byte*)&content;

yes, it's a byte now, but consider I want to change it in the future? how do I make byteArray contain content? (I don't care to copy it).

是的，它现在是一个字节，但考虑我将来要改变它？如何让byteArray包含内容？（我不在乎复制它）。

5 个解决方案

#1

The BitConverter class might be what you are looking for. Example:

BitConverter类可能正是您要找的。例：

int input = 123;
byte[] output = BitConverter.GetBytes(input);

If your enum was known to be an Int32 derived type, you could simply cast its values first:

如果您的枚举被称为Int32派生类型，您可以先简单地转换它的值：

BitConverter.GetBytes((int)commands.one);

#2

To convert any value types (not just primitive types) to byte arrays and vice versa:

要将任何值类型（不仅仅是基本类型）转换为字节数组，反之亦然：

    public T FromByteArray<T>(byte[] rawValue)
    {
        GCHandle handle = GCHandle.Alloc(rawValue, GCHandleType.Pinned);
        T structure = (T)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(T));
        handle.Free();
        return structure;
    }

    public byte[] ToByteArray(object value, int maxLength)
    {
        int rawsize = Marshal.SizeOf(value);
        byte[] rawdata = new byte[rawsize];
        GCHandle handle =
            GCHandle.Alloc(rawdata,
            GCHandleType.Pinned);
        Marshal.StructureToPtr(value,
            handle.AddrOfPinnedObject(),
            false);
        handle.Free();
        if (maxLength < rawdata.Length) {
            byte[] temp = new byte[maxLength];
            Array.Copy(rawdata, temp, maxLength);
            return temp;
        } else {
            return rawdata;
        }
    }

#3

You can use the BitConverter.GetBytes method to do this.

您可以使用BitConverter.GetBytes方法执行此操作。

#4

For anyone who's interested in how it works without using BitConverter you can do it like this:

对于那些不使用BitConverter而对它如何工作感兴趣的人，你可以这样做：

// Convert double to byte[]
public unsafe byte[] pack(double d) {
    byte[] packed = new byte[8]; // There are 8 bytes in a double
    void* ptr = &d; // Get a reference to the memory containing the double
    for (int i = 0; i < 8; i++) { // Each one of the 8 bytes needs to be added to the byte array
        packed[i] = (byte)(*(UInt64 *)ptr >> (8 * i)); // Bit shift so that each chunk of 8 bits (1 byte) is cast as a byte and added to array 
    }
    return packed;
}

// Convert byte[] to double
public unsafe double unpackDouble(byte[] data) {
    double unpacked = 0.0; // Prepare a chunk of memory ready for the double
    void* ptr = &unpacked; // Reference the double memory
    for (int i = 0; i < data.Length; i++) {
        *(UInt64 *)ptr |= ((UInt64)data[i] << (8 * i)); // Get the bits into the right place and OR into the double
    }
    return unpacked;
}

In reality it's much easier and safer to use BitConverter but it's fun to know!

实际上，使用BitConverter更容易，更安全，但知道它很有趣！

#5

You can also just do a simple cast and pass it into the array constructor. It also similar in length to the BitConverter method.

您也可以只进行一次简单的转换并将其传递给数组构造函数。它的长度也与BitConverter方法类似。

new[] { (byte)mode }

#1