说明：  C#文件内容高级搜索器，有一些高级的搜索选项，比如可遍历子目录进行查找，可指定要搜索文件的扩展名，可指定要搜索的文件内容中是否包含指定文字，在显示结果中，可以勾选只显示包含指定内容的文件，觉得这个搜索代码对学习C#还是有一定帮助的。
(C# file content Advanced search engine, there are some advanced search options, such as can traverse subdirectories to find, you can specify the file extension you want to search, you can specify the contents of the file to be searched whether to include the specified text, display the results, you can Check the display only files that contain the specified content, that this search code to learn C# or have some help. )