下载文件所对应的的 Content-type类型

图片：

Content.Headers.ContentType = new MediaTypeHeaderValue("image/png");

视频：

Content.Headers.ContentType = new MediaTypeHeaderValue("video/mp4")

.docx

Content.Headers.ContentType = new MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.wordprocessingml.document");

 

 

文件后缀	MIME TYPE
.doc	application/msword
.dot	application/msword
.docx	application/vnd.openxmlformats-officedocument.wordprocessingml.document
.dotx	application/vnd.openxmlformats-officedocument.wordprocessingml.template
.docm	application/vnd.ms-word.document.macroEnabled.12
.dotm	application/vnd.ms-word.template.macroEnabled.12
.xls	application/vnd.ms-excel
.xlt	application/vnd.ms-excel
.xla	application/vnd.ms-excel
.xlsx	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet 如果还是用application/vnd.ms-excel 谷歌和ie都不改名，识别未xlsx 但是火狐会自动改名未 xls 文件 xlsx请使用这个新版的
.xltx	application/vnd.openxmlformats-officedocument.spreadsheetml.template
.xlsm	application/vnd.ms-excel.sheet.macroEnabled.12
.xltm	application/vnd.ms-excel.template.macroEnabled.12
.xlam	application/vnd.ms-excel.addin.macroEnabled.12
.xlsb	application/vnd.ms-excel.sheet.binary.macroEnabled.12
.ppt	application/vnd.ms-powerpoint
.pot	application/vnd.ms-powerpoint
.pps	application/vnd.ms-powerpoint
.ppa	application/vnd.ms-powerpoint
.pptx	application/vnd.openxmlformats-officedocument.presentationml.presentation
.potx	application/vnd.openxmlformats-officedocument.presentationml.template
.ppsx	application/vnd.openxmlformats-officedocument.presentationml.slideshow
.ppam	application/vnd.ms-powerpoint.addin.macroEnabled.12
.pptm	application/vnd.ms-powerpoint.presentation.macroEnabled.12
.potm	application/vnd.ms-powerpoint.presentation.macroEnabled.12
.ppsm	application/vnd.ms-powerpoint.slideshow.macroEnabled.12
.zip	application/zip
.tar	application/x-tar