LINQ为了通过布尔 [英] Linq order by boolean

问题描述

我已经得到了我想要f.bar，这是一个字符串命令LINQ查询，但我也想通过f.foo来订购吧，这是一个布尔字段，第一。像下面的查询。

I've got a linq query that I want to order by f.bar, which is a string, but I also want to order it by f.foo, which is a boolean field, first. Like the query below.

(from f in foo
orderby f.foo, f.bar
select f)

虽然编译如下预期这是行不通的。它只是由f.bar忽略布尔领域的订单。

Although this compiles it doesn't work as expected. It just orders by f.bar ignoring the boolean field.

我是愚蠢，我知道，但我需要什么做的就是这种行为？

I'm being daft I know, but what do I need to do to get this behaviour?

感谢

推荐答案

这应该做工精细 - 它应当责令有实体假 foo的值，然后再那些具有真正 foo的值。

That should work fine - it should order the entities with a false foo value first, then those with a true foo value.

这在LINQ肯定工程的对象 - 这LINQ提供你实际使用

That certainly works in LINQ to Objects - which LINQ provider are you actually using?

下面是一个LINQ到对象例子确实的工作方式：

Here's a LINQ to Objects example which does work:

using System;
using System.Linq;

public static class Test
{
    public static void Main()
    {
        var data = new[]
        {
            new { x = false, y = "hello" },
            new { x = true, y = "abc" },
            new { x = false, y = "def" },
            new { x = true, y = "world" }
        };

        var query = from d in data
                    orderby d.x, d.y
                    select d;

        foreach (var result in query)
        {
            Console.WriteLine(result);
        }
    }

}

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