2020-12-20

使用 FileStream 类的构造方法创建 FileStream 类的实例

string path = "D:\\test.txt";
FileStream fileStream1 = new FileStream(path, FileMode.Open);
FileStream fileStream2 = new FileStream(path, FileMode.Open, FileAccess.Read);
FileStream fileStream3 = new FileStream(path, FileMode.Open, FileAccess.ReadWrite, FileShare.Read);
FileStream fileStream4 = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read, 10, FileOptions.None);

读取文件并显示到控制台上`

class Program
{
    
    
    static void Main(string[] args)
    {
    
    
        //定义文件路径
        string path = @"D:\\code\\student.txt";
        //判断是否含有指定文件
        if (File.Exists(path))
        {
    
    
            FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);
            //定义存放文件信息的字节数组
            byte[] bytes = new byte[fileStream.Length];
            //读取文件信息
            fileStream.Read(bytes, 0, bytes.Length);
            //将得到的字节型数组重写编码为字符型数组
            char[] c = Encoding.UTF8.GetChars(bytes);
            Console.WriteLine("学生的学号为：");
            //输出学生的学号
            Console.WriteLine(c);
            //关闭流
            fileStream.Close();
        }
        else
        {
    
    
            Console.WriteLine("您查看的文件不存在！");
        }
    }
}

向文件中写入文件
如果是中文的，bytes 数组的长度将不够用，改成使用byte[] bytes= Encoding.UTF8.GetBytes(message);的方式将数据从字符串类型转换为字节类型。

class Program
{
    
    
    static void Main(string[] args)
    {
    
    
        //定义文件路径
        string path = @"D:\\code\\student.txt";
        //创建 FileStream 类的实例
        FileStream fileStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
        //定义学号
        string msg = "1710026";
        //将字符串转换为字节数组
        byte[] bytes = Encoding.UTF8.GetBytes(msg);
        //向文件中写入字节数组
        fileStream.Write(bytes, 0, bytes.Length);
        //刷新缓冲区
        fileStream.Flush();
        //关闭流
        fileStream.Close();
    }
}