string str = "把,分,给,我";
Lista = new List ();
a.AddRange(str.Split(','));
MessageBox.Show((a.Count - 1).ToString());
// 普通版
string s1 = "123,345,567";
int num = 0;
foreach(char c in s1) {
if(c == ',') num++;
}
Console.WriteLine(num);
// Linq版
string s2 = "123,345,567";
Console.WriteLine(s2.Count(o => o == ','));