我有一段如下代码，定义一个接口iInterface，cBase实现iInterface，cChild继承cBase，UML为
预期是想要cBase.F()的执行逻辑，同时需要cChild的返回值，所以FF预期的输出
1: namespace ConsoleApplication1
2: {
3: class Program
4: {
5: static void Main(string[] args)
6: {
7: iInterface inf = new cChild();
8: FF(inf);
9:
10: Console.ReadLine();
11: }
12: static public void FF(iInterface inf)
13: {
14: Console.WriteLine(inf.F());
15: }
16: }
17:
18: public interface iInterface
19: {
20: string F();
21: }
22: public class cBase : iInterface
23: {
24: public string F()
25: {
26: Console.WriteLine("base.F1");
27: return "this is base";
28: }
29: }
30: public class cChild : cBase
31: {
32: public string F()
33: {
34: base.F();
35: return "this is child";
36: }
37: }
38: }
.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }
但是实际的结果是只能call到cBase的F函数，输出”this is base”
原因是我们定义的inf类型为iInterface，同时赋值的对象类型为cChild，但是cChild是没有实现iInterface的（继承至实现了接口的class也是不行的）。
实际运行时，inf向上找到了cBase有实现iInterface，所以调用了它的实现。
想达到预期的结果，可以将cChild也实现iInterface，如下：
1: public class cChild : cBase, iInterface
2: {
3: public string F()
4: {
5: base.F();
6: return "this is child";
7: }
8: }
修改后的UML为
输出结果为：
