C#创建模态与非模态窗口，程序没有其它的功能，主要是演示如何使用C#创建模态窗口和非模态窗口，运行效果如截图所示。-C# create modal and non-modal windows, no other program functions, mainly demonstrates how to create a modal window and non-modal window using C#, operating results as shown in the screenshot.