参考
http://blog.csdn.net/daigualu/article/details/54315564
示例:
List<int> test = new List<int>();
[0] [1] [2] [3] [4] [5] [6]
test.Add(9);test.Add(1);test.Add(9);test.Add(2);test.Add(9);test.Add(3);test.Add(9);
int t1 = test.Find(test1 => test1 == 9); //结果 t1 = 9
List<int> t2 = test.FindAll(test1 => test1 == 9); //结果 t2 = {9, 9, 9, 9}
int t3 = test.FindIndex(test1 => test1 == 9); //结果 t3 = 0
int t4 = test.FindIndex(1, test1 => test1 == 9); //结果 t4 = 2; 从[1]开始的第一个=9的元素下标
int t5 = test.FindIndex(1, 2, test1 => test1 == 9); //结果 t5 = 2 从[1]开始的2个元素内(即[1],[2]),查找第一个=9的元素的下标,如果第二个参数=1则无法找到,t5=-1;
int t6 = test.FindLast(test1 => test1 == 9); //结果 t6 = 9
int t7 = test.FindLastIndex(test1 => test1 == 9); //结果 t7 = 6
int t8 = test.FindLastIndex(5, test1 => test1 == 9); //结果 t8 = 4 从[0]-[5]元素中,返回最后一个=9的元素的下标
int t9 = test.FindLastIndex(3, 2, test1 => test1 == 9); //结果 t9 = 2 从[3]元素向前的2个元素内即([3],[2]),查找第一个=9的元素的下标,如果第二个参数=1,则无法找到,t9 = -1;