C#做的计算器，利用类的封装继承多态。。

C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\obj\Debug\ResolveAssemblyReference.cache C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\obj\Debug\WindowsApplication7.Form1.resources C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\obj\Debug\WindowsApplication9.Properties.Resources.resources C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\obj\Debug\WindowsApplication9.csproj.GenerateResource.Cache C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\bin\Debug\WindowsApplication9.exe C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\bin\Debug\WindowsApplication9.pdb C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\obj\Debug\WindowsApplication9.exe C:\Documents and Settings\yzq\My Documents\Visual Studio 2005\Projects\WindowsApplication9\WindowsApplication9\obj\Debug\WindowsApplication9.pdb