windows C#-显式实现接口成员

本示例声明一个接口IDimensions 和一个类 Box，显式实现了接口成员 GetLength 和 GetWidth。 通过接口实例 dimensions 访问这些成员。

interface IDimensions
{float GetLength();float GetWidth();
}class Box : IDimensions
{float lengthInches;float widthInches;Box(float length, float width){lengthInches = length;widthInches = width;}// Explicit interface member implementation:float IDimensions.GetLength(){return lengthInches;}// Explicit interface member implementation:float IDimensions.GetWidth(){return widthInches;}static void Main(){// Declare a class instance box1:Box box1 = new Box(30.0f, 20.0f);// Declare an interface instance dimensions:IDimensions dimensions = box1;// The following commented lines would produce compilation// errors because they try to access an explicitly implemented// interface member from a class instance://System.Console.WriteLine("Length: {0}", box1.GetLength());//System.Console.WriteLine("Width: {0}", box1.GetWidth());// Print out the dimensions of the box by calling the methods// from an instance of the interface:System.Console.WriteLine("Length: {0}", dimensions.GetLength());System.Console.WriteLine("Width: {0}", dimensions.GetWidth());}
}
/* Output:Length: 30Width: 20
*/

可靠编程

请注意，注释掉了 Main 方法中以下行，因为它们将产生编译错误。 显式实现的接口成员不能从类实例访问：

//System.Console.WriteLine("Length: {0}", box1.GetLength());
//System.Console.WriteLine("Width: {0}", box1.GetWidth());

另请注意 Main 方法中的以下行成功输出了框的尺寸，因为这些方法是从接口实例调用的：

System.Console.WriteLine("Length: {0}", dimensions.GetLength());
System.Console.WriteLine("Width: {0}", dimensions.GetWidth());