在iOS SDK9中废弃了之前用来播放视频的MPMoviePlayerController，改成了AVPlayer。
使用AVPlayer需要导入AVKit.framework这个框架，并且在需要使用的ViewController中添加 <AVKit/AVKit.h>和<AVFoundation/AVFoundation.h>两个头文件。
通过网络请求下载网络视频到iOS的沙盒中，之后获取到该视频在沙盒中的url，就可以通过AVPlayer播放该视频了。代码如下。
先获取沙盒中Documents的路径。
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">YES</span>);
<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *documentsDirectory = [paths objectAtIndex:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>];</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>
假设存储在Documents中的文件名为test.mp4，得到视频文件的绝对路径。
<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *fullPath = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> stringWithFormat:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@/%@"</span>, documentsDirectory, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"test.mp4"</span>];</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>
使用AVPlayer来播放该视频。
<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">NSURL *videoURL = [NSURL fileURLWithPath:fullPath]<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
AVPlayer *player = [AVPlayer playerWithURL:videoURL]<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player]<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
playerLayer<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.frame</span> = self<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.view</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.bounds</span><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
[self<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.view</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.layer</span> addSublayer:playerLayer]<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
[player play]<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>
fileURLWithPath，而不是URLWithString，前者用来访问本地视频，后者用来访问网络视频。
