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预示方法作为参数
原标题:Method with Predicate as Parameter

这是一个一般性问题,但这里是一例,寻求解决:

我有<条码>理论与设计;int, List<string>>。 我想对我提出各种看法。 我想要一种能够照顾到多种准则问题的方法,例如:

from x in Dictionary
where x.Value.Contains("Test")
select x.Key

from x in Dictionary
where x.Value.Contains("Test2")
select x.Key

• 寻找类似方法:

public int GetResult(**WhatGoesHere** filter)
{
    return from x in Dictionary.Where(filter)
           select x.Key;
}

用于:

int result;

result = GetResult(x => x.Value.Contains("Test"));
result = GetResult(x => x.Value.Contains("Test2"));

<>?

最佳回答

页: 1 Func<KeyValuePair<int, List<string>> bool>:

public int GetResult(Func<KeyValuePair<int, List<string>>, bool> filter)
{
    return (from x in Dictionary
            where filter(x)
            select x.Key).FirstOrDefault();
}

或者,Predicate<KeyValuePair<int, List<string>>>。 见http://stackoverflow.com/questions/665494/c-why-funct-bool-inffer-of-predicatet>。 这些天。

你正在使用<条码>x,意思是你最后例子中的两个不同内容,这将造成汇编错误。 更改<代码>x之一至:

x = GetResult(y => y.Value.Contains("Test1"));
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