示例代码：
public enum Foods
{
Burger,Pizza,Cake
}
private void button1_Click(object sender,EventArgs e)
{
Eat(0); // A
Eat((Foods)0); // B
//Eat(1); // C : won't compile : cannot convert from 'int' to 'Foods'
Eat((Foods)1); // D
}
private void Eat(Foods food)
{
MessageBox.Show("eating : " + food);
}
C行的代码不会编译,但是A行编译很好.
有没有什么特别的枚举与0值得到特殊待遇在这样的情况？
解决方法
是的,文字0可隐式转换为任何枚举类型,并表示该类型的默认值.根据C#语言规范,特别是关于枚举的1.10节：
The default value of any enum type is the integral value zero converted to the enum type. In cases where variables are automatically initialized to a default value,this is the value given to variables of enum types. In order for the default value of an enum type to be easily available,the literal 0 implicitly converts to any enum type. For the default value of an enum type to be easily available,the literal 0 implicitly converts to any enum type.
