一个演示objective-c下的协议与代理的示例程序，自己写的，希望能给大家启发或者帮助-A demonstration objective-c under the agreement with the agent of the sample program, write their own, and hope that they can inspire or help

这是一个swift开发的简单示例程序。目的是展示窗口的使用。(this is a ios app with swift , just to show how to use the window and bar.)