如何将字符串解析为可以为空的 int [英] How to parse a string into a nullable int

问题描述

我想在 C# 中将字符串解析为可为空的 int.IE.如果无法解析，我想取回字符串的 int 值或 null.

I'm wanting to parse a string into a nullable int in C#. ie. I want to get back either the int value of the string or null if it can't be parsed.

我有点希望这会奏效

int? val = stringVal as int?;

但这行不通，所以我现在的做法是我写了这个扩展方法

But that won't work, so the way I'm doing it now is I've written this extension method

public static int? ParseNullableInt(this string value)
{
    if (value == null || value.Trim() == string.Empty)
    {
        return null;
    }
    else
    {
        try
        {
            return int.Parse(value);
        }
        catch
        {
            return null;
        }
    }
}   

有没有更好的方法来做到这一点?

Is there a better way of doing this?

感谢 TryParse 的建议，我确实知道这一点，但结果大致相同.我更想知道是否有内置的框架方法可以直接解析为可为空的 int?

Thanks for the TryParse suggestions, I did know about that, but it worked out about the same. I'm more interested in knowing if there is a built-in framework method that will parse directly into a nullable int?

推荐答案

int.TryParse 可能更容易一些:

public static int? ToNullableInt(this string s)
{
    int i;
    if (int.TryParse(s, out i)) return i;
    return null;
}

编辑 @Glenn int.TryParse 内置于框架中".它和 int.Parse 是将字符串解析为整数的方式.

Edit @Glenn int.TryParse is "built into the framework". It and int.Parse are the way to parse strings to ints.

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