Swift开发 - 获取文件的MIMEType类型（根据后缀名自

使用方法：
let url = URL(fileURLWithPath: path)
let mimeType = weakself.mimeType(pathExtension: url.pathExtension)
print(mimeType)

导入import MobileCoreServices

//根据后缀获取对应的Mime-Type
func mimeType(pathExtension: String) -> String {
    if let uti = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension,pathExtension as NSString,nil)?.takeRetainedValue() {
        if let mimetype = UTTypeCopyPreferredTagWithClass(uti, kUTTagClassMIMEType)?.takeRetainedValue() {
            return mimetype as String
        }
    }
    //文件资源类型如果不知道，传万能类型application/octet-stream，服务器会自动解析文件类
    return "application/octet-stream"
}