Why do I always prompt notice:undefined index when uploading files according to the steps in the tutorial video?

Recently self-taught php in learning to upload files in a class encounter problems, the code is so:

Upload.html:

                 
  
           上传文件                    

upload.php:

    
  
       The Image
  
   

When run-time general prompt:

Notice: Undefined index: myFile in D:\xampp\htdocs\form\upload.php on line 15

is not defined? I am a small Bai Tiu advice, grateful!!!

Reply content:

Recently self-taught php in learning to upload files in a class encounter problems, the code is so:

Upload.html:

                 
  
           上传文件                    

upload.php:

    
  
       The Image
  
   

When run-time general prompt:

Notice: Undefined index: myFile in D:\xampp\htdocs\form\upload.php on line 15

is not defined? I am a small Bai Tiu advice, grateful!!!

PHP did not write much problem, but prompted undefined index description of the upload file error, enctype= "Multipart/form-data" is data is not date. This setting is wrong.

I am also looking for this problem, I upload pictures or anything can be, but the video will not be able to set any restrictions, I do not know you solved it

