C# 中的Stream流

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更好的阅读体验请查看原文:https://www.cnblogs.com/littleperilla/p/15948241.html

流就是一个类的对象,很多文件的输入输出操作都以类的成员函数的方式来提供;

流其实是一种信息的转换,是有序的,有输入和输出流(IO);

1.FileStream

文件流,读取和保存文件操作使用;

//写入
FileStream fs = new FileStream("data.txt", FileMode.OpenOrCreate);
string msg = "littlePerilla";
byte[] bytes = System.Text.Encoding.UTF8.GetBytes(msg);
fs.Write(bytes, 0, bytes.Length);
fs.Flush();
fs.Close();

//读取
FileStream fs = new FileStream("data.txt", FileMode.Open, FileAccess.Read);
byte[] bytes = new byte[fs.Length];
fs.Read(bytes, 0, bytes.Length);
char[] c = Encoding.UTF8.GetChars(bytes);
fs.Flush();
fs.Close();

2.StreamReader 和 StreamWriter

粒度为字符的流;

void StreamWrite()
{
	string path = "test.txt";
	//创建StreamWriter 类的实例
	StreamWriter streamWriter = new StreamWriter(path);
	streamWriter.WriteLine("Perilla");
	streamWriter.WriteLine("13112345678");
	//刷新缓存
	streamWriter.Flush();
	//关闭流
	streamWriter.Close();
}

void StreamReader()
{
	//定义文件路径
	string path = "test.txt";
	//创建 StreamReader 类的实例
	StreamReader streamReader = new StreamReader(path);
	//判断文件中是否有字符
	while (streamReader.Peek() != -1)
	{
		//读取文件中的一行字符
		string str = streamReader.ReadLine();
		Debug.Log(str);
	}
	streamReader.Close();
}

3.BinaryWriter 和 BinaryReader

粒度为字节的读写流;

// 读取文件
void ReadFile()          
{
	FileStream fs = new FileStream("data.txt", FileMode.Open, FileAccess.Read);
	BinaryReader r = new BinaryReader(fs);

	//以二进制方式读取文件中的内容
	int i = r.ReadInt32();
	float f = r.ReadSingle();
	double d = r.ReadDouble();
	bool b = r.ReadBoolean();
	string s = r.ReadString();
	Debug.Log(i);
	Debug.Log(f);
	Debug.Log(d);
	Debug.Log(b);
	Debug.Log(s);

	r.Close();
	fs.Close();
}

// 写入文件
void WriteFile()    
{
	FileStream fs = new FileStream("data.txt", FileMode.OpenOrCreate);
	BinaryWriter w = new BinaryWriter(fs);

	//以二进制方式向创建的文件中写入内容 
	w.Write(1123);                
	w.Write(0.3135f);             
	w.Write(0.3188946);           
	w.Write(true);                
	w.Write("LittlePerilla");     

	w.Close();
	fs.Close();
}

4.MemoryStream

内存的读写流,字节粒度,支持Position和Seek操作,自由度更高;

支持异步读写,不需要手动释放和开辟内存;

支持在任意位置修改操作;

class Program
{
    static void Main(string[] args)
    {
        string strValue = "LittlePerillaIsSuperHero";
        MemoryStream ms = new MemoryStream();
        ms.Write(Encoding.UTF8.GetBytes(strValue), 0, strValue.Length);

        Console.WriteLine(ms.Position);
        //打印测试
        byte[] byte1 = ms.GetBuffer();          
        string str1 = Encoding.UTF8.GetString(byte1);
        Console.WriteLine(str1);


        ms.Seek(2, SeekOrigin.Current);
        ms.ReadByte();
        ms.ReadByte();
        ms.ReadByte();
        ms.ReadByte();                    
        byte[] bytes3 = ms.ToArray();
        foreach (byte b in bytes3)
        {
            Console.Write(b + "-");
        }
        str1 = Encoding.UTF8.GetString(bytes3);
        Console.WriteLine("\n"+str1);
        //这里说明ms.ReadByte不会截断读完的数据

        MemoryStream ms2 = new MemoryStream();
        byte[] bytes6 = Encoding.UTF8.GetBytes("abcde");
        ms2.Write(bytes6, 0, bytes6.Length);
        Console.WriteLine(ms2.Position);
		
        //等价
        ms2.Position = 0;//ms2.Seek(0, SeekOrigin.Begin);  

        byte[] byteArray = new byte[5] { 110, 110, 110, 110, 110 };
        ms2.Read(byteArray, 2, 1);
        Console.WriteLine(Encoding.UTF8.GetString(byteArray));
        //结果为nnann,说明讲ms2中的数据读进byteArray中偏移2的位置,且只读取1个字节;

        //指定位置写入
        MemoryStream ms3 = new MemoryStream();
        byte[] bytesArr = Encoding.ASCII.GetBytes("abcdefg");
        ms3.Write(bytesArr, 0, bytesArr.Length);
        ms3.Position = 2;
        ms3.WriteByte(97);  //97代表的是a   这段代码的意思是,将原先第二个的c替换为a
        string str = Encoding.ASCII.GetString(ms3.ToArray());
        Console.WriteLine(str); //输出 abacdefg

        Console.ReadKey();
    }

}

5.NetworkStream

为网络访问提供数据的基础流;用于 Stream 在阻止模式下通过套接字发送和接收数据的方法;

可以将类用于 NetworkStream 同步和异步数据传输;

创建NetworkStream必须提供Socket

详细不适合在这里讨论;待完善吧;