web.config配置如下

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<staticContent>
<mimeMap fileExtension="." mimeType="text/plain" />
</staticContent>
</system.webServer>
</configuration>

fileExtension="."表示无后缀文件,mimeType="text/plain"这里根据实际情况配置,我这里因为是要访问一个无后缀的json文件,就设置为text/plain
如果想让文件被下载,则mimeType设置为application/octet-stream
还有个强制下载类型:application/force-download