sketch里我已经把图片从速写本里添加进去了，但是它说我图片丢失或者不能读取The file "dog2.JPG" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.
https://stackoverflow.com/questions/31763657/the-file-starting-gif0000-gif-is-missing-or-inaccessible-make-sure-the-url-is