有没有办法使用"使用"但保持文件打开？

Question

通常,"使用"是正确访问和处理文件流的优选方法.

我经常需要打开文件(如下所示).在这种情况下可以采用"使用"结构吗？

public class logger
{
    private StreamWriter sw;
    public logger(string fileName)
    {
        sw = new StreamWriter(fileName, true);
    }

    public void LogString(string txt)
    {
        sw.WriteLine(txt);
        sw.Flush();
    }

    public void Close()
    {
        sw.Close();
    }
}

Answer 1

是的,你制作Logger一次性产品并在处理方法中处理掉这条流.

// I make it sealed so you can use the "easier" dispose pattern, if it is not sealed
// you should create a `protected virtual void Dispose(bool disposing)` method.
public sealed class logger : IDisposable
{
    private StreamWriter sw;
    public logger(string fileName)
    {
        sw = new StreamWriter(fileName, true);
    }

    public void LogString(string txt)
    {
        sw.WriteLine(txt);
        sw.Flush();
    }

    public void Close()
    {
        sw.Close();
    }

    public void Dispose()
    {
        if(sw != null)
            sw.Dispose();
    }
}