C#中的匿名对象”;使用“;声明可靠
本文关键字:使用 声明 对象 | 更新日期: 2023-09-27 18:26:24
想象一下这个片段:
using System;
public class Report {
static int Level=0;
public static void WriteLine(string Message) {
Console.WriteLine("{0}{1}",new String(' ',4*Level),Message);
}
public class Indent:IDisposable {
public Indent() { Report.WriteLine("{"); ++Level; }
void IDisposable.Dispose() { --Level; Report.WriteLine("}"); }
}
}
class Program {
static void Main() {
Report.WriteLine("Started");
Report.WriteLine("Calling submethod");
using(new Report.Indent()) {
Report.WriteLine("Submethod started");
using(new Report.Indent()) Report.WriteLine("Subsub, maybe?");
Report.WriteLine("Submethod reporting everything is fine");
Report.WriteLine("Submethod finished");
}
Report.WriteLine("Finished");
}
}
产生结果:
Started
Calling submethod
{
Submethod started
{
Subsub, maybe?
}
Submethod reporting everything is fine
Submethod finished
}
Finished
在内部,我使用using(new Report.Indent())
,而不是坚持使用我发现的唯一文档版本,即using(Report.Indent r=new Report.Indent())
。
然而,在我的简短版本中,我能确定每次都会对那些未命名的缩进对象调用Dispose()
吗?
P.S
// btw, I used word "anonymous" in the title, but I'm not sure that's what new objects that aren't assigned to any named variable should be called
是的,using
枚举即使是"匿名对象"也总是被处理掉。
在内部,using
存储在局部变量中输入块时使用的任何值。此存储的值在退出块时被释放。