LINQ从String []追加到StringBuilder [英] LINQ to append to a StringBuilder from a String[]

问题描述

我有一个String数组，我想通过LINQ添加到字符串生成器中.

I've got a String array that I'm wanting to add to a string builder by way of LINQ.

我基本上要说的是对于此数组中的每个项目，在此StringBuilder后面添加一行".

What I'm basically trying to say is "For each item in this array, append a line to this StringBuilder".

我可以使用foreach循环很容易地做到这一点，但是下面的代码似乎什么也没做.我想念什么?

I can do this quite easily using a foreach loop however the following code doesn't seem to do anything. What am I missing?

stringArray.Select(x => stringBuilder.AppendLine(x));

在什么地方起作用:

foreach(String item in stringArray)
{
  stringBuilder.AppendLine(item);
}

推荐答案

如果您坚持以LINQy方式这样做:

If you insist on doing it in a LINQy way:

StringBuilder builder = StringArray.Aggregate(
                            new StringBuilder(),
                            (sb, s) => sb.AppendLine(s)
                        );

或者，如 Luke 在另一篇文章的评论中指出的，你可以说

Alternatively, as Luke pointed out in a comment on another post, you could say

Array.ForEach(StringArray, s => stringBuilder.AppendLine(s));

Select不起作用的原因是，Select用于投影并创建投影的IEnumerable.所以这行代码

The reason that Select does not work is because Select is for projecting and creating an IEnumerable of the projection. So the line of code

StringArray.Select(s => stringBuilder.AppendLine(s))

不会在每次迭代中遍历StringArray调用stringBuilder.AppendLine(s)的情况.而是创建一个可以枚举的IEnumerable<StringBuilder>.

does not iterate over the StringArray calling stringBuilder.AppendLine(s) on each iteration. Rather, it creates an IEnumerable<StringBuilder> that can be enumerated over.

我想你可以说

var e = stringArray.Select(x => stringBuilder.AppendLine(x));
StringBuilder sb = e.Last();
Console.WriteLine(sb.ToString());

但这真的很可怕.

这篇关于LINQ从String []追加到StringBuilder的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！