公共字段与自动属性 [英] Public Fields versus Automatic Properties

问题描述

我们经常被告知我们应该通过getter和setter方法​​（在C＃属性）类领域，而不是暴露领域向外界保护封装。

但也有很多时候一个字段是只是为了保持一个值，并且不需要任何计算以获取或设置。对于这些我们都做到这个数字：

 公共类图书
{
    私人字符串_title;    公共字符串标题
    {
          {返回_title; }
          集合{_title =价值; }
    }
}
 

好吧，我有一个秘密，我不忍写所有的（实际上，它是没有写出来，这是不必看它），所以我去流氓和使用的公共领域。

然后来了C＃3.0和我看到他们增加了自动属性：

 公共类图书
{
    公共字符串名称{搞定;组;}
}
 

这是整洁的，我很感激，但说真的，有什么比只是让公共领域？

如此不同

 公共类图书
{
    公共字符串称号;
}
 

解决方案

在一个相关问题我以前有一段时间，有一个帖子中的链接杰夫的博客，解释一些差异。

与公共变量属性

• 反射原理不同的变量与属性，因此，如果你靠反射，它更容易使用的所有属性。


• 您不能对数据绑定变量。



• 变量更改为一个属性是一个重大更改。例如：

    TryGetTitle（出book.Title）; //需要一个变量
   

We're often told we should protect encapsulation by making getter and setter methods (properties in C#) for class fields, instead of exposing the fields to the outside world.

But there are many times when a field is just there to hold a value and doesn't require any computation to get or set. For these we would all do this number:

public class Book
{
    private string _title;

    public string Title
    {
          get{ return _title;  }
          set{ _title = value; }
    }
}

Well, I have a confession, I couldn't bear writing all that (really, it wasn't having to write it, it was having to look at it), so I went rogue and used public fields.

Then along comes C# 3.0 and I see they added automatic properties:

public class Book
{
    public string Title {get; set;} 
}

which is tidier, and I'm thankful for it, but really, what's so different than just making a public field?

public class Book
{
    public string Title;
}

解决方案

In a related question I had some time ago, there was a link to a posting on Jeff's blog, explaining some differences.

Properties vs. Public Variables

• Reflection works differently on variables vs. properties, so if you rely on reflection, it's easier to use all properties.
• You can't databind against a variable.

• Changing a variable to a property is a breaking change. For example:

  TryGetTitle(out book.Title); // requires a variable
  

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