c#常用的文本操作

1.从index截取到字符串结束:

string.Substring(index)

2.从index截取length长度的字符串:

string.Substring(index,length)

3.查找字符串最先出现的index:

//如果没找到,会返回-1

int index =string.IndexOf(s)

4.用字符串截取字符串:

int index =string.IndexOf(s);

string.Substring(index,index) // 左边

string temp = str.Substring(index, string.Length-string.Substring(0, str.IndexOf(s)).Length); // 右边

5.从中间取

int i = str.IndexOf(leftstr) + leftstr.Length;

string temp = str.Substring(i, str.IndexOf(rightstr, i) - i);

6.取文本中间到List集合

public static string Between(string str, string leftstr, string rightstr)

　　List<string> list = new List<string>();

　　int leftIndex = str.IndexOf(leftstr);//左文本起始位置

　　int leftlength = leftstr.Length;//左文本长度

　　int rightIndex = 0;

　　string temp = "";

　　while (leftIndex != -1)
          {
                rightIndex = str.IndexOf(rightstr, leftIndex + leftlength);
                if (rightIndex == -1)
                {
                    break;
                }
                temp = str.Substring(leftIndex + leftlength, rightIndex - leftIndex - leftlength);
                list.Add(temp);
                leftIndex = str.IndexOf(leftstr, rightIndex + 1);
            }
            return list;

}

7.倒序

public static string StrReverse(string str)
{
　　char[] chars = str.ToCharArray();
　　StringBuilder sb = new StringBuilder();
　　for (int i = 0; i < chars.Length; i++)
　　{
　　sb.Append(chars[chars.Length - 1 - i]);
　　}
　　return sb.ToString();
}