问题
We know that in iOS 6 mobile safari supports HTML input file tag to upload images. I just created an HTML file like this and it worked fine in mobile safari. But when I loaded it in a UIWebView, I found I could still tap the "Choose file" button to choose an image file, but after I tapped "done" and returned to the UIWebView, the web page in the UIWebView reloaded and no file was attached to the HTML form. Is that a restriction to UIWebView?
回答1:
I have sorted it out. This is due to I put the UIWebview loading web page function in "-viewWillAppear:(BOOL)animated". So each time when the "take photo" modal view hides, the UIWebview reloads the url. I have fixed it and I can confirm now that the HTML input file tag upload function works well in UIWebview, too.
来源：https://stackoverflow.com/questions/17302848/ios-6-html-input-file-tag-doesnt-work-if-load-the-web-page-in-uiwebview