C#中的@和$ 占位符

c#中@的三种用法：

1.忽略转移字符

string str = "C:\\windows\\system32";

string str = @"C:\windows\system32";

2.字符串跨行

string str = "SELECT * FROM Employee AS e"

　　+ "INNER JOIN Contact AS c"

　　+ "ON e.ContactID = c.ContactID"

　　+ "ORDER BY c.LastName";

string str = @"SELECT * FROM Employee AS e

　　INNER JOIN Contact AS c"

　　ON e.ContactID = c.ContactID"

　　ORDER BY c.LastName";

3.将关键字作为标识符使用

int @int = 1;

c#中$的使用

简化string.Format()写法

string name = "上帝";

int age = 0;

string str = string.Format("my name is {0},I`m {1} years old",name,age);

可简写为

string str = $"my name is {name},I`m {age} years old";

需要输出"时使用\"

需要输出{}时使用{{ }}

string str = $"my \"name\" is {{{name}}},I`m {age} years old";