Yii2文件上传图片、txt文件成功，但是上传excel的xls、xlsx、rar等MIME类型失败 [ 技术分享 ]

一、当遇到上传图片、txt文件成功，但是上传excel的xls、xlsx、rar等失败时，在rules()里添加 'checkExtensionByMimeType' => false 代码可解决此类问题

public function rules(){
		return [
			[['imageFile'],'file','skipOnEmpty'=>false,'checkExtensionByMimeType' => false,'extensions'=>'png,jpg,txt,xls,xlsx'],
		]; 
	 }

二、input:file属性详解 来源：http://www.haorooms.com/post/input_file_leixing

属性值有以下几个比较常用：

accept：表示可以选择的文件MIME类型，多个MIME类型用英文逗号分开，常用的MIME类型见下表。

multiple：是否可以选择多个文件，多个文件时其value值为第一个文件的虚拟路径。

1、accept 只能选择png和gif图片

2、multiple 多文件上传

3、常用MIME类型 后缀名 MIME名称 .3gpp audio/3gpp, video/3gpp .ac3 audio/ac3 .asf allpication/vnd.ms-asf .au audio/basic .css text/css .csv text/csv .doc application/msword
.dot application/msword
.dtd application/xml-dtd
.dwg image/vnd.dwg
.dxf image/vnd.dxf .gif image/gif
.htm text/html
.html text/html
.jp2 image/jp2
.jpe image/jpeg .jpeg image/jpeg .jpg image/jpeg
.js text/javascript, application/javascript
.json application/json
.mp2 audio/mpeg, video/mpeg
.mp3 audio/mpeg
.mp4 audio/mp4, video/mp4
.mpeg video/mpeg
.mpg video/mpeg
.mpp application/vnd.ms-project
.ogg application/ogg, audio/ogg
.pdf application/pdf
.png image/png
.pot application/vnd.ms-powerpoint
.pps application/vnd.ms-powerpoint
.ppt application/vnd.ms-powerpoint
.rtf application/rtf, text/rtf
.svf image/vnd.svf
.tif image/tiff
.tiff image/tiff
.txt text/plain
.wdb application/vnd.ms-works
.wps application/vnd.ms-works
.xhtml application/xhtml+xml
.xlc application/vnd.ms-excel
.xlm application/vnd.ms-excel
.xls application/vnd.ms-excel
.xlt application/vnd.ms-excel
.xlw application/vnd.ms-excel
.xml text/xml, application/xml
.zip aplication/zip
.xlsx application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

三、上传样式美化 css input[type=file] 样式美化，input上传按钮美化，见此链接博文 http://www.haorooms.com/post/css_input_uploadmh