DownloadImage download image with a specific scale, depend on ffmpeg.

Mail send mail in HTML format.

OptimizeImage make image limited in a specific scaling.

SaveImage save image with a specific scale, depend on ffmpeg.

WxDecrypt 第三方平台消息解密.

WxEncrypt 第三方平台消息加密.

WxSign 第三方平台签名.

Graphql struct.

WxAPI struct.

File interface.