小编Ans*_*hul的帖子

以下代码中的以下行不会产生任何影响:

string1.Replace(string1.Substring(firstchar, lastchar - firstchar), "##");

string1 保持不变,使用IndexOf时返回相同的索引.

while (firstchar != string1.LastIndexOf("test"))
{

    firstchar = string1.IndexOf("test");
    lastchar = string1.IndexOf(" ");
    using (StreamWriter writer = new StreamWriter("C:\\textfile1.txt"))
    {
        writer.WriteLine(string1.Substring(firstchar, lastchar - firstchar));
        writer.WriteLine();
        writer.Dispose();
    }
    string1.Replace(string1.Substring(firstchar, lastchar - firstchar), "##");

}