是否有比嵌套"使用"更好的确定性处置模式？

Question

在C#中,如果我想确定性地清理非托管资源,我可以使用"using"关键字.但是对于多个依赖对象,这最终会进一步嵌套:

using (FileStream fs = new FileStream("c:\file.txt", FileMode.Open))
{
    using (BufferedStream bs = new BufferedStream(fs))
    {
        using (StreamReader sr = new StreamReader(bs))
        {
            // use sr, and have everything cleaned up when done.
        }
    }
}

在C++中,我习惯于使用析构函数来执行此操作:

{    
    FileStream fs("c:\file.txt", FileMode.Open);
    BufferedStream bs(fs);
    StreamReader sr(bs);
    // use sr, and have everything cleaned up when done.
}

在C#中有更好的方法吗？还是我坚持多层次的嵌套？

Answer 1

您不必嵌套多个使用:

using (FileStream fs = new FileStream("c:\file.txt", FileMode.Open))
using (BufferedStream bs = new BufferedStream(fs))
using (StreamReader sr = new StreamReader(bs))
{
    // all three get disposed when you're done
}

Answer 2

您可以在开头大括号之前将using语句放在一起,如下所示:

  using (StreamWriter w1 = File.CreateText("W1"))
  using (StreamWriter w2 = File.CreateText("W2"))
  {
      // code here
  }

http://blogs.msdn.com/ericgu/archive/2004/08/05/209267.aspx