3

我在一个类中有这个结构：

[System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential, Pack = 1)]
public struct MyStruct
{
    public byte StartOfText;
    public byte DisableChecksum;
    public byte ProtocolVersion;
    public byte Code;
    public Int16 Size;
    public byte[] Data;
    public byte EndOfText;

    public MyStruct(CommandCode commandCode, string commandData)
    {
        this.StartOfText = 0x02;
        this.DisableChecksum = 0x00;
        this.ProtocolVersion = 0x35;
        this.Code = (byte)commandCode;
        this.Size = (Int16)commandData.Length;
        this.Data = new byte[commandData.Length];
        this.Data = Encoding.ASCII.GetBytes(commandData);
        this.EndOfText = 0x03;
    }

    public byte[] ToByteArray()
    {
        byte[] arr = null;
        IntPtr ptr = IntPtr.Zero;
        try
        {
            Int16 size = (Int16)Marshal.SizeOf(this);
            arr = new byte[size];
            ptr = Marshal.AllocHGlobal(size);
            Marshal.StructureToPtr(this, ptr, true);
            Marshal.Copy(ptr, arr, 0, size);
        }
        catch (Exception e)
        {
            MessageBox.Show(e.Message);
        }
        finally
        {
            Marshal.FreeHGlobal(ptr);
        }

        return arr;
    }
}

现在，假设我在程序中初始化该结构的一个新实例，执行以下操作：

Protocol.MyStruct Cmd = new Protocol.MyStruct(CommandCode.LOAD_FILE, "TEST");
byte[] StructData = Cmd.ToByteArray();

初始化时，我可以看到 MyStruct.Data 正在使用字符串常量（0x54、0x45、0x53、0x54）的内容正确初始化。每个字符

但是当调用 MyStruct.TiByteArray() 并跟踪数组中的值时，数据部分现在是（0xa0、0xa6、0x91 和 0x03）。

数组的其余部分没问题，数据被正确复制。

代码有什么问题，我错过了什么？

4

1 回答 1

2

这可能在某些情况下有效。但是，Data 的长度是固定的。如果将 Data 定义为字符串，它可能会更有用。

[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct MyStruct
{
    const int ARRAY_SIZE = 100;

    public byte StartOfText;
    public byte DisableChecksum;
    public byte ProtocolVersion;
    public byte Code;
    public Int16 Size;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = ARRAY_SIZE)]
    public byte[] Data;
    public byte EndOfText;

    public MyStruct(CommandCode commandCode, string commandData)
    {
        this.StartOfText = 0x02;
        this.DisableChecksum = 0x00;
        this.ProtocolVersion = 0x35;
        this.Code = (byte)commandCode;
        this.Size = (Int16)commandData.Length;
        this.Data = new byte[ARRAY_SIZE];
        byte[] bytes = Encoding.ASCII.GetBytes(commandData);
        Array.Copy(bytes, Data, bytes.Length);
        //this.Data = Encoding.ASCII.GetBytes(commandData);
        this.EndOfText = 0x03;
    }

    public byte[] ToByteArray()
    {
        byte[] arr = null;
        IntPtr ptr = IntPtr.Zero;
        try
        {
            int size = Marshal.SizeOf(this);
            arr = new byte[size];
            ptr = Marshal.AllocHGlobal(size);
            Marshal.StructureToPtr(this, ptr, true);
            Marshal.Copy(ptr, arr, 0, size);
        }
        catch (Exception e)
        {
            MessageBox.Show(e.Message);
        }
        finally
        {
            Marshal.FreeHGlobal(ptr);
        }

        return arr;
    }
}
于 2014-01-14T14:04:43.330 回答