MemoryStream来自bytes数组,具有不同类型的数据

Question

我想创建一个包含int32,int16,单值的内存流.使用二进制文件是没用的,所以我试图创建字节数组.因为值是不同的类型,我不知道如何正确地做到这一点.所以我尝试这样做:

byte[] tab = new byte[]{2,0,0,0,3,0,3,0} - 2是int32(四个字节),另外两个是int16(两个字节)

工作正常,但是当我想添加一些单个值时,它会产生错误.我不能这样做:

byte[] tab = new byte[]{2,0,0,0,3,0,3,0,4.4f,5.6f}

我必须有正确格式的流,因为这个流将在这个方法中读取:

short[] rawData;
 float[] modulusData;
   public void rawData(Stream s)
        {

            BinaryReader br = new BinaryReader(s);

            int dataCount = br.ReadInt32();

            if (dataCount > 0)
            {
                rawData = new short[dataCount];
                for (int i = 0; i < dataCount; i++)
                    rawData[i] = br.ReadInt16();
            }
            else
                rawData = new short[0];

            dataCount = br.ReadInt32();

            if (dataCount > 0)
            {
                modulusData = new float[dataCount];
                for (int i = 0; i < dataCount; i++)
                    modulusData[i] = br.ReadSingle();
            }
            else
                modulusData = new float[0];
        }

任何人都知道如何做到这一点？

Answer 1

相反,你原来的说法,BinaryWriter是正是你想要的.这就是它的设计目标.特别是,如果你BinaryReader以后再使用它是完全合适的.

你没有说明为什么你不想使用它,但它确实是你应该使用的:

using (MemoryStream stream = new MemoryStream())
{
    using (BinaryWriter writer = new BinaryWriter(stream))
    {
        writer.Write(2);
        writer.Write((short) 3);
        writer.Write((short) 3);
        writer.Write(4.4f);
        writer.Write(5.6f);
    }
    byte[] bytes = stream.ToArray();
}

这将生成一个包含以下数据的字节数组:

[Int32    ] [Int16] [Int16] [Single   ] [Single   ]
02 00 00 00 03 00   03 00   CD CC 8C 40 33 33 B3 40

需要注意的一点 - 您的写作描述会写下这些值:

- Int32
- Int16
- Int16
- Single
- Single

...但您的阅读代码将为:

- Int32 (value 2)
- Int16
- Int16
- Int32 (this wasn't written - so you're reading data from the first Single!)
- ???

换句话说,如果您以前的尝试BinaryWriter失败,因为它们看起来像我的初始代码,那是因为您忘记了

writer.Write(2);

在写入Int16值之后,说出存在多少单个值.

请注意,如果您不需要将值作为字节数组,则无需调用ToArray- 只需返回流(不会丢弃它).但是,在阅读之前,您需要"回放"它.例如:

public Stream GetData()
{
    MemoryStream stream = new MemoryStream();
    BinaryWriter writer = new BinaryWriter(stream); // Don't close at the end!
    writer.Write(2);
    writer.Write((short) 3);
    writer.Write((short) 3);
    writer.Write(2); // Extra count for the Single values
    writer.Write(4.4f);
    writer.Write(5.6f);
    writer.Flush(); // May not be required...

    stream.Position = 0; // Rewind so stream can be read again
    return stream;
}