将通用列表转换为 CSV 字符串 [英] Converting a generic list to a CSV string

问题描述

我有一个整数值列表 (List)，想生成一串逗号分隔的值.即列表中的所有项目输出到单个逗号分隔列表.

I have a list of integer values (List) and would like to generate a string of comma delimited values. That is all items in the list output to a single comma delimted list.

我的想法...1. 将列表传递给一个方法.2.使用stringbuilder迭代列表并附加逗号3.测试最后一个字符，如果是逗号，则删除.

My thoughts... 1. pass the list to a method. 2. Use stringbuilder to iterate the list and append commas 3. Test the last character and if it's a comma, delete it.

你有什么想法?这是最好的方法吗?

What are your thoughts? Is this the best way?

如果将来我不仅要处理整数(我当前的计划)，还要处理字符串、长整数、双精度数、布尔值等，我的代码将如何更改?我想让它接受任何类型的列表.

How would my code change if I wanted to handle not only integers (my current plan) but strings, longs, doubles, bools, etc, etc. in the future? I guess make it accept a list of any type.

推荐答案

框架已经为我们做的事情真是太神奇了.

It's amazing what the Framework already does for us.

List<int> myValues;
string csv = String.Join(",", myValues.Select(x => x.ToString()).ToArray());

对于一般情况:

IEnumerable<T> myList;
string csv = String.Join(",", myList.Select(x => x.ToString()).ToArray());

如您所见，实际上并没有什么不同.请注意，您可能需要将 x.ToString() 实际用引号括起来(即，""" + x.ToString() + """) 以防 x.ToString() 包含逗号.

As you can see, it's effectively no different. Beware that you might need to actually wrap x.ToString() in quotes (i.e., """ + x.ToString() + """) in case x.ToString() contains commas.

有关此轻微变体的有趣阅读:请参阅埃里克·利珀特 (Eric Lippert) 博客上的逗号狡辩.

For an interesting read on a slight variant of this: see Comma Quibbling on Eric Lippert's blog.

注意:这是在 .NET 4.0 正式发布之前编写的.现在我们只能说

Note: This was written before .NET 4.0 was officially released. Now we can just say

IEnumerable<T> sequence;
string csv = String.Join(",", sequence);

使用重载 String.Join(string, IEnumerable<;T>).此方法会自动将每个元素 x 投影到 x.ToString().

using the overload String.Join<T>(string, IEnumerable<T>). This method will automatically project each element x to x.ToString().

这篇关于将通用列表转换为 CSV 字符串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！