string.Join-“无法从IEnumerable转换为string []"； [英] string.Join - "cannot convert from IEnumerable to string[]"

问题描述

非常简单的扩展方法无法编译:

Very simple extension method not compiling:

public static string Join(this string text, params string[] stringsToJoin)
{
    return String.Join(", ", stringsToJoin.Where(s => !string.IsNullOrEmpty(s)));
}

我得到无法从'System.Collections.Generic.IEnumerable'转换为'string []'"

I get "cannot convert from 'System.Collections.Generic.IEnumerable' to 'string[]'"

我想念什么?

推荐答案

的过载仅在.NET 4.0中添加了接受 IEnumerable< String> 的 String.Join .看来您正在针对早期版本进行编译.

The overload of String.Join which accepts an IEnumerable<String> was only added in .NET 4.0. It seems you're compiling against an earlier version.

解决此问题并使它与.NET 3.5兼容的最简单方法是简单地调用 .ToArray():

The easiest way to fix this and make it compatible with .NET 3.5 would be to simply call .ToArray():

public static string Join(this string text, params string[] stringsToJoin)
{
    return String.Join(", ", stringsToJoin.Where(s => !string.IsNullOrEmpty(s))
                                          .ToArray());
}

这篇关于string.Join-“无法从IEnumerable转换为string []"；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！