2

在 C# 中将固定字节或 char[100] 转换为托管 char[] 的最佳方法是什么？我最终不得不使用指针算法，我想知道是否有更简单的方法——比如 memcpy 或其他方法？

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;

namespace StructTest
{

    [StructLayout(LayoutKind.Explicit)]
    unsafe struct OuterType
    {
        private const int BUFFER_SIZE = 100;

        [FieldOffset(0)]
        private int transactionType;

        [FieldOffset(0)]
        private fixed byte writeBuffer[BUFFER_SIZE];

        public int TransactionType
        {
            get { return transactionType; }
            set { transactionType = value; }
        }

        public char[] WriteBuffer
        {
            set
            {
                char[] newBuffer = value;

                fixed (byte* b = writeBuffer)
                {
                    byte* bptr = b;
                    for (int i = 0; i < newBuffer.Length; i++)
                    {
                         *bptr++ = (byte) newBuffer[i];
                    }
                }
            }

            get
            {
                char[] newBuffer = new char[BUFFER_SIZE];

                fixed (byte* b = writeBuffer)
                {
                    byte* bptr = b;
                    for (int i = 0; i < newBuffer.Length; i++)
                    {
                        newBuffer[i] = (char) *bptr++;
                    }
                }

                return newBuffer;
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            OuterType t = new OuterType();
            t.WriteBuffer = "hello there".ToCharArray();
            System.Console.WriteLine(t.WriteBuffer);
        }
    }
}
4

2 回答 2

3

您可以为此使用Marshal.Copy。请注意，它还为 byte[] 重载，这可能是更合适的数据类型。

于 2009-07-26T19:03:24.687 回答
0

我不知道对固定变量进行转换的更好方法。然而，使这更简单的一种方法是完全避免使用固定变量。而是使用普通的 C# 数组并将其标记为 UnmanagedType.ByValArray

[FieldOffset(0), MarshalAs(UnmanagedType.ByValArray, SizeConst = BUFFER_SIZE)]
private byte[] writeBuffer;

然后，您可以使用简单的 LINQ 查询来转换数据。完整解决方案如下

[StructLayout(LayoutKind.Explicit)]
unsafe struct OuterType
{
    private const int BUFFER_SIZE = 100;

    [FieldOffset(0)]
    private int transactionType;

    [FieldOffset(0), MarshalAs(UnmanagedType.ByValArray, SizeConst = BUFFER_SIZE)]
    private byte[] writeBuffer;

    public int TransactionType
    {
        get { return transactionType; }
        set { transactionType = value; }
    }

    public char[] WriteBuffer
    {
        set { writeBuffer = value.Cast<byte>().ToArray(); }
        get { return writeBuffer.Cast<char>().ToArray(); }
    }
}
于 2009-07-26T19:04:34.497 回答