我有一个扩展方法是工作确定投字符串值成各种类型，这看起来是这样的：

I have an extension method that is working ok to cast string values into various types, which looks something like this:

public static T ToType<T> (this string value, T property)
    {
        object parsedValue = default(T);
        Type type = property.GetType();

        try
        {
            parsedValue = Convert.ChangeType(value, type);
        }
        catch (ArgumentException e)
        {
            parsedValue = null;
        }

        return (T)parsedValue;
    }

我不满调用方法时，这看起来的样子，但是：

I'm unhappy about the way this looks when calling the method, however:

myObject.someProperty = stringData.ToType(myObject.someProperty);

指定酒店仅获得属性的类型似乎是多余的。我宁愿用一个签名是这样的：

Specifying the property just to obtain the property's type seems redundant. I would rather use a signature like this:

public static T ToType<T> (this string value, Type type) { ... }

和为T最终成为类型的类型。这将拨打电话更清洁的：

and have T end up to be the Type of type. This would make calls much cleaner:

myObject.someProperty = stringData.ToType(typeof(decimal));

当我尝试调用这种方式，但是，编辑抱怨说，扩展方法的返回类型不能从使用推导。我可以链接T可Type参数？

When I try to call this way, however, the editor complains that the return type of the extension method can't be infered from usage. Can I link T to the Type argument?

我在想什么？

感谢

推荐答案

这是你在找什么？我已经添加了一个额外的渔获量情况下的转换无效也

Is this what you are looking for? I've added an extra catch for cases where the cast isn't valid also

Decimal i = stringName.ToType<Decimal>();

public static T ToType<T>(this string value)
{
     object parsedValue = default(T);
     try
     {
         parsedValue = Convert.ChangeType(value, typeof(T));
     }
     catch (InvalidCastException)
     {
         parsedValue = null;
     }
     catch (ArgumentException)
     {
         parsedValue = null;
     }
     return (T)parsedValue;
} 

修改

快捷方式来解决安东的评论

a shortcut approach to fix Anton's comment

if (typeof(T).IsValueType)
   return default(T);