c# - 我可以在这个片段中以某种方式用 using 块替换 Initialize() 和 Close() 方法调用吗？

Question

您是否可以建议帮助摆脱调用 Initialize() 和 Close() 方法并将其替换为 using 块？

还是这种方法完全可以？

（想法是确保当 FooWriter 的消费者写入一些字符串并以此结束时，Writer 将被释放。）

class Program
    {
        static void Main(string[] args)
        {
            var writer  = new FooWriter();

            writer.Initialize();

            foreach (var s in args)
                writer.Write(s);

            writer.Cose();
    }


public class FooWriter
{

    public StreamWriter Writer;

    public void Initialize()
    {
        Writer = new StreamWriter("MyFile.txt", false);
    }

    public void Write(string line)
    {
        if(Writer==null)
            throw new NullReferenceException(Writer, "Writer"); // Guard Writer

        Writer.WriteLine(line);
    }

    public void Close()
    {
        Writer.Dispose();
    }

}

Answer 1

您可以通过制作FooWriter一个IDisposable. 并将初始化移动到其构造函数中：

public class FooWriter : IDisposable {

    public StreamWriter Writer;

    public FooWriter()
    {
        Writer = new StreamWriter("MyFile.txt", false);
    }

    public void Write(string line)
    {
        // You do not need to guard the writer, because constructor sets it
        if(Writer==null)
            throw new NullReferenceException(Writer, "Writer"); // Guard Writer

        Writer.WriteLine(line);
    }

    public void Dispose()
    {
        Writer.Dispose();
    }

}

Answer 2

你可以让 FooWriter 实现 IDisposable 并在构造函数中调用 Initialize() ，然后你可以使用 at 如下：

class FooWriter : IDisposable
{
   private StreamWriter Writer;
   public FooWriter()
   {
      Writer = new StreamWriter("MyFile.txt", false);
   }
   public void Write(string line)
   {
     Writer.WriteLine(line);
   }
   public void Dispose()
   {
        Writer.Dispose();
   }
}


// use it

using (var writer = new FooWriter())
{
  foreach (var s in args)
                writer.Write(s);
}

Answer 3

我会像这样改变你的实现：

• 使类实现 IDisposable
• 在构造函数中初始化编写器

• 删除异常

  公共类 FooWriter : IDisposable { public StreamWriter Writer { get; 私人套装；}

  public FooWriter(string fileName)
  {
      Writer = new StreamWriter(fileName, false);
  }
  
  public void Write(string line)
  {                        
      Writer.WriteLine(line);
  }      
  
  public void Dispose()
  {
      Dispose(true);
      GC.SuppressFinalize(this);
  }
  
  protected virtual void Dispose(bool disposeManaged)
  {
      if (disposeManaged)
          Writer.Dispose();
  }
  

  }