通用TryParse扩展方法 [英] Generic TryParse Extension method

问题描述

从此处获取的代码

我想听听有关这种扩展方法的专家意见。我打算使用它，但是想听听我可能遇到的任何已知问题。

I would like to hear some expert opinions on this extension method. I do plan to use it, but would like to hear about any known problems i may face.

我更好地使用基本类型TryParse方法？

Am i better of using on primative types TryParse methods?

public static T? TryParse<T>(this object obj) where T : struct
        {
            if (obj == null) return null;

            T? result = null;
            TypeConverter converter = TypeDescriptor.GetConverter(typeof(T));
            if (converter != null)
            {
                try
                {
                    string str = obj.ToString();
                    result = (T)converter.ConvertFromString(str);
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }

            return result;
        }

推荐答案

TryParse pattern最好遵循标准模式，它允许与非结构体一起使用：

The TryParse pattern is best following the standard pattern, which allows use with non-structs, too:

public static bool TryParse<T>(string s, out T value) {
    TypeConverter converter = TypeDescriptor.GetConverter(typeof(T));
    try {
        value = (T) converter.ConvertFromString(s);
        return true;
    } catch {
        value = default(T);
        return false;
    }
}

注意我已经接受了一个 string 这里，因为这是我最常见的意思是 TryParse ;否则， Convert.ChangeType 可能更合适。

Note I've accepted a string here, because that is what me most commonly mean by TryParse; otherwise, Convert.ChangeType might be more appropriate.

我认为没有理由成为扩展方法根据问题示例中的这个），并且肯定不适合污染对象扩展方法太多。

I see no reason for this to be an extension method (as per this in the question's example), and certainly it is inadvisable to pollute object with too many extension methods.

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