如何从WordPress默认允许上传的文件类型中，禁止上传某些特定类型的文件，如WordPress默认允许上传 .exe 后缀名的可运行文件，那么我们怎么禁止用户在WordPress后台发表文章时上传 .exe 后缀名的文件呢？这就是本文要解答的问题。
首先，我们要知道WordPress支持上传哪些类型的文件，我们可以在当前主题的functions.php中插入以下php代码，然后打开博客首页，查看网页源代码，即可看到一个完整的支持列表（看完后，记得删除）：
print_r(wp_get_mime_types());
下面是以上代码输出的结果，这里供大家参考，也免了大家去写代码看结果。下面是WordPress默认允许上传的文件类型列表：
// []中括号中的名称代表文件名后缀名/扩展名
// => 后面的名称代表的是后缀名所在应的文件MIME信息
Array
(
[jpg|jpeg|jpe] => image/jpeg
[gif] => image/gif
[png] => image/png
[bmp] => image/bmp
[tif|tiff] => image/tiff
[ico] => image/x-icon
[asf|asx|wax|wmv|wmx] => video/asf
[avi] => video/avi
[divx] => video/divx
[flv] => video/x-flv
[mov|qt] => video/quicktime
[mpeg|mpg|mpe] => video/mpeg
[mp4|m4v] => video/mp4
[ogv] => video/ogg
[mkv] => video/x-matroska
[txt|asc|c|cc|h] => text/plAIn
[csv] => text/csv
[tsv] => text/tab-separated-values
[ics] => text/calendar
[rtx] => text/richtext
[CSS] => text/css
[htm|html] => text/html
[mp3|m4a|m4b] => audio/mpeg
[ra|ram] => audio/x-realaudio
[wav] => audio/wav
[ogg|oga] => audio/ogg
[mid|midi] => audio/midi
[wma] => audio/wma
[mka] => audio/x-matroska
[rtf] => application/rtf
[js] => application/JavaScript
[pdf] => application/pdf
[swf] => application/x-shockwave-flash
[class] => application/java
[tar] => application/x-tar
[zip] => application/zip
[gz|gzip] => application/x-gzip
[rar] => application/rar
[7z] => application/x-7z-compressed
[exe] => application/x-msdownload
[doc] => application/msword
[pot|pps|ppt] => application/vnd.ms-powerpoint
[wri] => application/vnd.ms-write
[xla|xls|xlt|xlw] => application/vnd.ms-excel
[mdb] => application/vnd.ms-access
[mpp] => application/vnd.ms-project
[docx] => application/vnd.openxmlformats-officedocument.wordprocessingml.document
[docm] => application/vnd.ms-word.document.macroEnabled.12
[dotx] => application/vnd.openxmlformats-officedocument.wordprocessingml.template
[dotm] => application/vnd.ms-word.template.macroEnabled.12
[xlsx] => application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
[xlsm] => application/vnd.ms-excel.sheet.macroEnabled.12
[xlsb] => application/vnd.ms-excel.sheet.binary.macroEnabled.12
[xltx] => application/vnd.openxmlformats-officedocument.spreadsheetml.template
[xltm] => application/vnd.ms-excel.template.macroEnabled.12
[xlam] => application/vnd.ms-excel.addin.macroEnabled.12
[pptx] => application/vnd.openxmlformats-officedocument.presentationml.presentation
[pptm] => application/vnd.ms-powerpoint.presentation.macroEnabled.12
[ppsx] => application/vnd.openxmlformats-officedocument.presentationml.slideshow
[ppsm] => application/vnd.ms-powerpoint.slideshow.macroEnabled.12
[potx] => application/vnd.openxmlformats-officedocument.presentationml.template
[potm] => application/vnd.ms-powerpoint.template.macroEnabled.12
[ppam] => application/vnd.ms-powerpoint.addin.macroEnabled.12
[sldx] => application/vnd.openxmlformats-officedocument.presentationml.slide
[sldm] => application/vnd.ms-powerpoint.slide.macroEnabled.12
[onetoc|onetoc2|onetmp|onepkg] => application/onenote
[odt] => application/vnd.oasis.opendocument.text
[odp] => application/vnd.oasis.opendocument.presentation
[ods] => application/vnd.oasis.opendocument.spreadsheet
[odg] => application/vnd.oasis.opendocument.graphics
[odc] => application/vnd.oasis.opendocument.chart
[odb] => application/vnd.oasis.opendocument.database
[odf] => application/vnd.oasis.opendocument.formula
[wp|wpd] => application/wordperfect
)
上面的内容，大家看了可能眼花缭乱，其实只要记住，在每一行中，左边中括号中的名称是文件的后缀名（或者叫扩展名），右边 => 后面的名称代表的是后缀名所对应的文件MIME信息，这个我们不用管。
现在言归正传，如果想禁止用户在WordPress后台发表文章时上传特定后缀名的文件，我们可以在当前主题的functions.php中添加以下php代码：
add_filter('upload_mimes', 'custom_upload_mimes');
function custom_upload_mimes( $existing_mimes=array() ) {
// 注意中括号中的名称，必须取自上面支持列表中中括号内的名称
unset( $existing_mimes['exe'] ); //此处禁止了上传exe后缀名的文件
return $existing_mimes;
}
如果想禁止上传更多后缀名的文件，可以复制第5行的代码，粘贴到第5行代码以后，第7行代码之前，把其中的exe，改成要禁止上传的后缀名即可，如：
add_filter('upload_mimes', 'custom_upload_mimes');
function custom_upload_mimes( $existing_mimes=array() ) {
// 注意中括号中的名称，必须取自上面支持列表中中括号的名称
unset( $existing_mimes['exe'] ); //此处禁止了上传exe后缀名的可运行文件
unset( $existing_mimes['jpg|jpeg|jpe'] ); //此处禁止了上传jpg、jpeg和jpe后缀名的压缩文件
unset( $existing_mimes['gif'] ); //此处禁止了上传gif后缀名的图片文件
unset( $existing_mimes['png'] ); //此处禁止了上传png后缀名的图片文件
return $existing_mimes;
}
经过此项设置，用户如果在后台上传禁止的文件类型，那么会得到这样的提示：
