1、操作符重载
a、构造器转换——将一个类型值显示或隐式赋给另一个类型
将Nullable类型转换为ValueTypepublic static explicit operator T(T? value)
{
return value.Value;
}
将ValueType类型转换为Nullablepublic static implicit operator T?(T value)
{
return new T?(value);
}
b、操作符重载
函数将被编译器翻译为特定名称函数，必须为static、public
操作符重载示例public static int operator +(Truck t1, Truck t2)
{
return t1.capacity + t2.capacity;
}
public static Truck operator ++ (Truck t)
{
t.Capacity++;
return t;
}
public static bool operator ==(Truck t1, Truck t2)
{
if (t1.Capacity == t2.Capacity)
return true;
return false;
}
public static bool operator !=(Truck t1, Truck t2)
{
if (t1.Capacity == t2.Capacity)
return false;
return true;
}
//负号
public static Truck operator -(Truck t)
{
return new Truck(-t.Capacity);
}
//减号
public static Truck operator -(Truck t1, Truck t2)
{
return new Truck(t1.Capacity-t2.Capacity);
}
2、Nullable值的操作
Nullable类型是继承于ValueType的类型，内含两个字段，一个是hasValue，一个是value
Nullable值的使用int? a = 5;
double? b = null ;
Console.WriteLine("a={0}, b={1}", a, b);
空接合符 ??
空接合符int? a = null;
int? b = 5;
Console.WriteLine(a??10);
Console.WriteLine(b ?? 100);
上例输出：
3、泛型委托
泛型委托示例public delegate T Callback<T>(T t) where T : Truck;
static void Main()
{
Callback<Truck> c = null;
c += delegate(Truck t) { Console.WriteLine(t); return t; };
c(new Truck(100));
}
