C#类型转换 C#类型转换

string str1 = Console.ReadLine(); string str2 = Console.ReadLine(); int x = Convert.ToInt32(str1); int y = Convert.ToInt32(str2); int result = x + y; Console.WriteLine(result); Console.ReadKey();

隐式类型转换（implicit）

不丢失精度的转换

int x = int.MaxValue; long y = x;

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不丢失精度的隐式类型转换

子类向父类的转换

using System; namespace Test { class User { public void Login() { Console.Write("user login\n"); } } class Member : User { public void Profile() { Console.WriteLine("member profile\n"); } } class GuildMember : Member { public void JoinGuild() { Console.WriteLine("guild member join\n"); } } class Program { static void Main(string[] args) {GuildMember gm = new GuildMember(); Member m = gm; User u = m; u.Login(); m.Login(); m.Profile(); gm.Login(); gm.Profile(); gm.JoinGuild(); Console.ReadKey(); } } }

装箱（boxing）

显示类型转换（explicit）

可能丢失精度，甚至发生错误，即cast。

ushort maxval = ushort.MaxValue; uint x = 65536; ushort y = (ushort)x; //0

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显示类型转换

拆箱（unboxing）
建议使用Convert工具类
ToString()与数据类型的Parse/TryParse方法
Parse只能解析格式正确的数据

自定义类型转换操作符

using System; namespace Test { class User { public int age; public static explicit operator Member(User user) { Member member = new Member(); member.age = user.age; return member; } } class Member { public int age = 1000; } class Program { static void Main(string[] args) { User u = new User(); Member m = (Member)u; Console.WriteLine(m.age); Console.ReadKey(); } } }