测试一个属性没有返回前空 [英] Test if a Property is not Null before Returning

问题描述

我有以下属性。

public MyType MyProperty {get;set;}

我要改变这个属性，这样，如果该值为null，它会首先填充值，然后返回...但的没有的使用私有成员变量

I want to change this property so that if the value is null, it'll populate the value first, and then return it... but without using a private member variable.

举例来说，如果我是这样做的：

For instance, if I was doing this:

public MyType MyProperty 
{
    get
    {
        if (_myProperty != null)
            return _myProperty
        else
           _myProperty = XYZ;
            return _myProperty;
    }
    set
    {
        _myProperty = value;
    }
}

这可能吗？或者我需要的成员变量来完成它？

is this possible? Or do I need the member variable to get it done?

推荐答案

您需要一个成员变量和一个完整的财产申报。自动实现属性的只有的适用，如果他们围绕一个领域琐碎的包装，没有涉及到逻辑。你可以稍微简化的getter代码，顺便说一句：

You need a member variable and a full property declaration. Automatically implemented properties are only applicable if they're trivial wrappers around a field, with no logic involved. You can simplify your getter code slightly, btw:

get
{
    if (_myProperty == null)
    {
       _myProperty = XYZ;
    }
    return _myProperty;
}

（注意，这一切都不是线程安全的，无需额外的锁定，但我。假设没关系）

(Note that none of this is thread-safe without extra locking, but I assume that's okay.)

顺便说一句，你已经有无的私有成员变量，如果您使用自动实现的属性 - 它只是编译器生成它。

By the way, you already have a private member variable if you're using automatically implemented properties - it's just that the compiler's generating it for you.

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