StringBuilder:如何获取最终的String？

Question

有人告诉我,用StringBuilder连接字符串会更快.我已经更改了我的代码,但是我没有看到任何属性或方法来获取最终的构建字符串.

我怎样才能得到这个字符串？

Answer 1

您可以使用.ToString(),以获得String从StringBuilder.

Answer 2

当你说"将字符串与字符串构建器连接起来更快"时,只有当你重复(重复 - 重复)连接到同一个对象时才会这样.

如果您只是将2个字符串连接起来并立即对结果执行某些操作string,则无需使用StringBuilder.

我刚刚偶然发现Jon Skeet很好地写了这篇文章:http://www.yoda.arachsys.com/csharp/stringbuilder.html

如果你正在使用StringBuilder,那么为了得到结果string,这只是一个问题ToString()(不出所料).

Answer 3

使用StringBuilder完成处理后,使用ToString方法返回最终结果.

来自MSDN:

using System;
using System.Text;

public sealed class App 
{
    static void Main() 
    {
        // Create a StringBuilder that expects to hold 50 characters.
        // Initialize the StringBuilder with "ABC".
        StringBuilder sb = new StringBuilder("ABC", 50);

        // Append three characters (D, E, and F) to the end of the StringBuilder.
        sb.Append(new char[] { 'D', 'E', 'F' });

        // Append a format string to the end of the StringBuilder.
        sb.AppendFormat("GHI{0}{1}", 'J', 'k');

        // Display the number of characters in the StringBuilder and its string.
        Console.WriteLine("{0} chars: {1}", sb.Length, sb.ToString());

        // Insert a string at the beginning of the StringBuilder.
        sb.Insert(0, "Alphabet: ");

        // Replace all lowercase k's with uppercase K's.
        sb.Replace('k', 'K');

        // Display the number of characters in the StringBuilder and its string.
        Console.WriteLine("{0} chars: {1}", sb.Length, sb.ToString());
    }
}

// This code produces the following output.
//
// 11 chars: ABCDEFGHIJk
// 21 chars: Alphabet: ABCDEFGHIJK