解决。

我的代码运行正常，并且播放视频。问题是在下载视频的URL中，它获取一个字符串与url，而不是视频（因此下载和打开文件方法不会抛出错误）

My code works good and play videos. The problem was in the URL to download the video, it gets a string with the url and not the video (therefore download and open file method didin't throw error)

总结一下，toUrl（）的工作原理。

Summarizing, toUrl() works.

感谢@Gandhi的回复。

Thanks @Gandhi for your replies.