如何：显式实现接口成员（C# 编程指南）
本示例声明一个 接口IDimensions 和一个类 Box，该类显式实现接口成员 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 = (IDimensions)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: 30
Width: 20
*/
可靠编程
请注意 Main 方法中下列代码行被注释掉，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());还请注意，Main 方法中的下列代码行成功输出框的尺寸，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());