file extensions volume changes for V1.0 features : batch change file extensions...

代码说明：

文件扩展名批量修改器V1.0 功能：批量修改文件扩展名 使用方法：用户可以选择某个目录，然后对该目录下（包括子目录）的某类文件的扩展名，进行批量修改，可修改成用户设定的扩展名类型。-file extensions volume changes for V1.0 features : batch change file extensions Use : Users can select a directory, then the directory (including subdirectories) in the expansion of certain documents, and changes in volume can be transformed into a user-defined extension types.