c# - 验证属性中的值

Question

所以我听说验证属性中的值是这样的:

//dummy example, let's assume that I want my value without dots
public string MyProp
{
    set
    {
        if(value.Contains('.'))
            throw new ArgumentException("Must not contain '.'", "value");
    }
}

是错误的，我应该避免它。

但在早些时候我被告知这是好方法。我们可以使用封装，只有一个地方可以检查、DRY 等。

我的小例子有什么问题吗？

Answer 1

在属性 setter 中抛出异常并没有错。但是您应该抛出一个 ArgumentException，并且还实际设置该属性的值!

private string _myprop;
public string MyProp{
    set{
       if(value.Contains('.')) throw new ArgumentException("Must not contain .");
       this._myprop=value;
    }
    get { return this._myprop; }
}

来自 article on best practices in MSDN :

Property getters should be simple operations without any preconditions. If a getter might throw an exception, consider redesigning the property to be a method. This recommendation does not apply to indexers. Indexers can throw exceptions because of invalid arguments.

It is valid and acceptable to throw exceptions from a property setter.