c# lamda,var 匿名类

lambda 是实例化委托的一个参数，是一个方法
1.0 委托
2.0 匿名方法,delegate 关键字
3.0 lambda 表达式，参数列表 => goesto 方法体
4.0 省略参数类型，参数类型由委托推算出来，是语法糖
5.0 如何方法体只有一行，能够去掉大括号，分号
6.0 能够省掉 new 关键字

objec,var 匿名类3.0
4.0 dynamic 避开编译器检查
var 匿名类，是只读的,var是语法糖，由编译器自动推算

public delegate void NoReturnNoParameter();
public delegate void WithReturnWithPara(int x, int y);

public void Show()
{

}
public void Show3(int id ,int name)
{

}

{
//1.0 委托
NoReturnNoParameter method = new NoReturnNoParameter(this.Show);
}

{
//2.0 匿名方法,delegate 关键字；
int i = 10;
WithReturnWithPara method3 = new WithReturnWithPara(delegate (int id, int name)
{
Console.WriteLine("i="+i);
Console.WriteLine($"{id}{name} 高级班");
});
method3.Invoke(123,456);
}

{
//3.0 lambda 表达式，参数列表 => goesto 方法体
int i = 10;
WithReturnWithPara method3 = new WithReturnWithPara( (int id, int name)=>
{
Console.WriteLine("i=" + i);
Console.WriteLine($"{id}{name} 高级班");
});
method3.Invoke(123, 456);
}

{
//4.0 省略参数类型，参数类型由委托推算出来，是语法糖
int i = 10;
WithReturnWithPara method3 = new WithReturnWithPara((id,name) =>
{
Console.WriteLine("i=" + i);
Console.WriteLine($"{id}{name} 高级班");
});
method3.Invoke(123, 456);
}

{
//5.0 如何方法体只有一行，能够去掉大括号，分号
int i = 10;
WithReturnWithPara method3 = new WithReturnWithPara((id, name)
=>Console.WriteLine($"{id}{name} 高级班")
);

method3.Invoke(123, 456);
}
{
//6.0 能够省掉 new 关键字；
int i = 10;
WithReturnWithPara method3 = (id, name)=> Console.WriteLine($"{id}{name} 高级班");

method3.Invoke(123, 456);
}
{
WithReturnWithPara method = new WithReturnWithPara(Show3);
method += this.Show3;
method += (id, name) => Console.WriteLine();
}

{
//objec,var 匿名类3.0
object model = new
{
id = 2,
name = "csj",
age = 22
};
// model.id; 不能点出来字段，编译器不承认，只能传obj,运行时承认；

} { //4.0 dynamic 避开编译器检查 dynamic dmodel = new { Id=1, name="csj" }; Console.WriteLine(dmodel.Id); } { //var 匿名类，是只读的,var是语法糖，由编译器自动推算 var vmodel = new { id = 3, name = "csj" }; Console.WriteLine(vmodel.id); Console.WriteLine(vmodel.GetType()); //vmodel.id = 2; }