验证邮箱

namespace _12判断邮箱
{
class Program
{
static void Main(string[] args)
{
//Person per = new Person();
//https://www.wendangku.net/doc/c35193601.html, = "sk";
//WeakReference wrf = new WeakReference(per);//标记了弱引用
//per = null;
//// GC.Collect();
//object o = wrf.Target;
//if (o != null)
//{
// Person p = o as Person;
// Console.WriteLine(https://www.wendangku.net/doc/c35193601.html,);
//}
//else
//{
// Console.WriteLine("只能重新创建了");
//}
//Console.ReadKey();





//判断用户输入的是否是邮箱.
//Console.WriteLine("请您输入邮箱");
//string email = Console.ReadLine();
//bool result = email.Contains("@");//该字符串在变量中是否存在
//if (result)
//{
// Console.WriteLine("是邮箱");
//}
//else
//{
// Console.WriteLine("不是邮箱");
//}
//Console.ReadKey();
//. { "马龙", "迈克尔乔丹", "雷吉米勒", "蒂姆邓肯", "科比布莱恩特" },请输出最长的字符串。
//string[] names = {"卡卡西","种哥","研究僧","风斯托罗斯基" };
//string longName = GetMaxLengNameByStringArray(names);
//Console.WriteLine(longName);
//Console.ReadKey();

//string[] names = { "中国", "美国", "巴西", "澳大利亚", "加拿大" };
//for (int i = 0; i < names.Length/2; i++)
//{
// string str = names[i];
// names[i] = names[names.Length - 1 - i];
// names[names.Length - 1 - i] = str;
//}
//for (int i = 0; i < names.Length; i++)
//{
// Console.Write(names[i]+"\t");
//}
//Console.ReadKey();


string str = "传说在传智播客.net部门有个讲师叫小杨,小杨很帅,很纯洁,小杨是智慧和勇敢的化身.第一次听人这么说我不相信,于是我怀着试试看的心情来到了传智播客,见到了传说中的小杨。哇塞,小杨岂止是帅,简直就是帅的无法用言语来形容.";

string keyWord = "小杨";
int index = 0;
int count = 0;
while ((index=str.IndexOf(keyWord,index))!=-1)
{
count++;
Console.WriteLine("{0}出现了{1}次,索引位置为{2}",keyWord,count,index);
index += keyWord.Length;
}

Console.ReadKey(true);
}

private static string GetMaxLengNameByStringArray(string[] names)
{
string name = names[0];
for (int i = 0; i < names.Length; i++)
{

if (name.Length{
name = names[i];
}
}
return name;
}