字符串处理

记录在使用过程中字符串处理方法

一、字符串列表合并并以相应符合分割

　　使用string.Join(string separator, string[] value)比使用循环的方式更加简便

List<string> test = new List<string>();
test.Add("1");
test.Add("2");
test.Add("3");
test.Add("4");
var str = string.Join(",", test.ToArray());

 二、String.Split 方法有6个重载函数

　　

1) public string[] Split(params char[] separator)
2) public string[] Split(char[] separator, int count)
3) public string[] Split(char[] separator, StringSplitOptions options)
4) public string[] Split(string[] separator, StringSplitOptions options)
5) public string[] Split(char[] separator, int count, StringSplitOptions options)
6) public string[] Split(string[] separator, int count, StringSplitOptions options)

下边我们通过一些实例来说明下怎么使用(以下string words = "1,2.3,,4";)：

1. public string[] Split(params char[] separator)

string[] split = words.Split(new Char[] { ',' });//返回:{"1","2.3","","4"}
string[] split = words.Split(new Char[] { ',', '.' });//返回:{"1","2","3","","4"}

2. public string[] Split(char[] separator, int count)

string[] split = words.Split(new Char[] { ',', '.' }, 2);//返回:{"1","2.3,,4"}
string[] split = words.Split(new Char[] { ',', '.' }, 6);//返回:{"1","2","3","","4"}

3. public string[] Split(char[] separator, StringSplitOptions options)

string[] split = words.Split(new Char[] { ',', '.' }, StringSplitOptions.RemoveEmptyEntries);//返回:{"1","2","3","4"} 不保留空元素
string[] split = words.Split(new Char[] { ',', '.' }, StringSplitOptions.None);//返回:{"1","2","3","","4"} 保留空元素

4. public string[] Split(string[] separator, StringSplitOptions options)

string[] split = words.Split(new string[] { ",", "." }, StringSplitOptions.RemoveEmptyEntries);//返回:{"1","2","3","4"} 不保留空元素
string[] split = words.Split(new string[] { ",", "." }, StringSplitOptions.None);//返回:{"1","2","3","","4"} 保留空元素

5. public string[] Split(char[] separator, int count, StringSplitOptions options)

string[] split = words.Split(new Char[] { ',', '.' }, 2, StringSplitOptions.RemoveEmptyEntries);//返回:{"1","2.3,,4"} 不保留空元素
string[] split = words.Split(new Char[] { ',', '.' }, 6, StringSplitOptions.None);//返回:{"1","2","3","","4"} 保留空元素

6. public string[] Split(string[] separator, int count, StringSplitOptions options)

string[] split = words.Split(new string[] { ",", "." }, 2, StringSplitOptions.RemoveEmptyEntries);//返回:{"1","2.3,,4"} 不保留空元素
string[] split = words.Split(new string[] { ",", "." }, 6, StringSplitOptions.None);//返回:{"1","2","3","","4"} 保留空元素

需要注意的是没有重载函数public string[] Split(string[] separator)，所以我们不能像VB.NET那样使用words.Split(",")，而只能使用words.Split(',')！很多人都很奇怪为什么把双引号改为单引号就可以了？看了上边的重载函数该知道答案了吧^_^

split总结来自博客：http://www.cnblogs.com/luluping/archive/2009/04/30/1446654.html