上传文件时后端先判是否符合条件，不符合的拒绝上传

// 文件为大小文件的依据是ParseMultipartForm的maxMemory参数的大小
// 获取文件大小的接口&＃xff0c;上传小文件时&＃xff0c;文件类型为&＃xff1a;multipart.sectionReadCloser
type Size interface {Size() int64
}// 获取文件信息的接口&＃xff0c;上传大文件时&＃xff0c;文件类型为&＃xff1a; *os.File
type Stat interface {Stat() (os.FileInfo, error)
}icon, _, err :&＃61; req.FormFile("icon")if statInterface, ok :&＃61; icon.(Stat); ok {fileInfo, err :&＃61; statInterface.Stat()if err &＃61;&＃61; nil {if fileInfo.Size() > (maxIconSize) {code &＃61; errParseFileFailedmsg &＃61; fmt.Sprint("上传文件不要超过", maxIconSize>>20, "M")return}} else if sizeInterface, ok :&＃61; icon.(Size); ok {if sizeInterface.Size() > (maxIconSize) {code &＃61; errParseFileFailedmsg &＃61; fmt.Sprint("上传文件不要超过", maxIconSize>>20, "M")return}}}if err !&＃61; nil {code &＃61; errParseFileFailedmsg &＃61; err.Error()return}defer icon.Close()