Revert "重命名"

This reverts commit 17229f2056e4767fc51dd61ca543b4228c935fa5.

ChainofResponsibility/ChainofResponsibility.csproj

@@ -41,8 +41,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="BillHandler.cs" />
-    <Compile Include="Bill.cs" />
+    <Compile Include="IBillOperation.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>