c# streamreader类用于从流中读取字符串。它继承自textreader类，它提供read()和readline()方法从流中读取数据。

c# streamreader示例：读取一行

下面来看看一个streamreader类的简单例子，它从文件中读取一行数据。

using system;
using system.io;
public class streamreaderexample
{
    public static void main(string[] args)
    {
        filestream f = new filestream("e:\\myoutput.txt", filemode.openorcreate);
        streamreader s = new streamreader(f);

        string line = s.readline();
        console.writeline(line);
        string line2 = s.readline();
        console.writeline(line2);
        s.close();
        f.close();
    }
}

假设e:\myoutput.txt文件的内容如下 -

this is line 1
this is line 2
this is line 3
this is line 4

执行上面示例代码，得到以下输出结果 -

this is line 1
this is line 2

c# streamreader示例：读取所有行

下面代码演示如何使用 streamreader 来读取文件：myoutput.txt中的所有行内容 -

using system;
using system.io;
public class streamreaderexample
{
    public static void main(string[] args)
    {
        filestream f = new filestream("e:\\myoutput.txt", filemode.openorcreate);
        streamreader s = new streamreader(f);

        string line = "";
        while ((line = s.readline()) != null)
        {
            console.writeline(line);
        }
        s.close();
        f.close();
    }
}

执行上面示例代码，得到以下输出结果 -

this is line 1
this is line 2
this is line 3
this is line 4