自做的c#控件，适用于winform的文件选择按钮，类似于web的文件上传控件,在windows状态下有的时候需要用户指定一个文件，比如单机版的winform程序初始化的时候需要用户指定Access数据库文件等，很实用的。-Since to do the c# Control, applied to WinForm document select button, similar to web file upload control, a state in the windows sometimes requires a user to specify a file, such as stand-alone version of the WinForm initialization procedure when the need user-specified Access database files and so on, very practical.