加载/卸载HTML5时iOS Safari内存泄漏< video> [英] iOS Safari memory leak when loading/unloading HTML5 <video>

问题描述

我开发了一个带有几个UIWebViews的iPad应用程序，它采用以下HTML和JavaScript。由于iPad一次只能播放一个视频，因此我不会加载视频，直到关注特定的网络视图。

这是通过调用 UIWebView上的stringByEvaluatingJavaScriptFromString 方法，向JS方法 getFocus（）发送调用。同样，当Web视图不再需要时，我会调用lostFocus（）来卸载视频。这使得另一个UIWebView可以播放另一个视频。

到目前为止，这么好。一切都很完美。除了一件事：这会导致内存泄漏。每次查看时，我都试着重新加载UIWebView（而不是使用JS卸载视频），那没用。

 < div id =videoDiv>>我也尝试了数十种不同的JavaScript变体，标签变体等等。 ;< / DIV> 
 
< script type =text / javascript> 
 var movieDiv = document.getElementById（'videoDiv'），
 movieHtml ='< video id =videosrc =../ Documents /<％= VideoFileName％> width =768height =911>< / video>'; 
 
 var gotFocus = function（）{
 movieDiv.innerHTML = movieHtml; 
 var movie = document.getElementById（'video'）; 
 movie.play（）; 
 movie.addEventListener（'pause'，function（）{
 movie.currentTime = 0; 
 movie.play（）; 
}，false）; 
}; 
 var lostFocus = function（）{
 movieDiv.innerHTML =''; 
}; 
< / script> 
  

解决方案

我终于解决了这个问题！解决方案是清空src并加载一个不存在的视频。这不会导致内存泄漏。看看：

 < div id =videoDiv>< / div> 
 
< script type =text / javascript> 
 var movieDiv = document.getElementById（'videoDiv'），
 movieHtml ='< video id =videosrc =width =768height =911><视频>'; 
 
 movieDiv.innerHTML = movieHtml; 
 var movie = document.getElementById（'video'）; 
 
 var gotFocus = function（）{
 movie.src ='../Documents/<%= VideoFileName％>'; 
 movie.load（）; 
 movie.play（）; 
 movie.addEventListener（'pause'，function（）{
 movie.currentTime = 0; 
 movie.play（）; 
}，false）; 
}; 
 var lostFocus = function（）{
 movie.src =''; 
 movie.load（）; //此行可能被删除，请参阅评论
}; 
< / script> 
  

I've developed an iPad app with several UIWebViews that takes the following HTML and JavaScript. Since the iPad can only play one video at a time, I don't load the video until the particular web view is focused.

This is done by calling the stringByEvaluatingJavaScriptFromString method on the UIWebView, sending in a call to the JS method getFocus(). Similarly, when the web view is no longer needed I call lostFocus() to unload the video. This enables another UIWebView to play another video.

So far, so good. Everything works perfectly. Except for one thing: This causes a memory leak. Whenever viewing

I've tried reloading the UIWebView (instead of unloading the video with JS), that didn't work. I've also tried a zillion of different JavaScript variations, tag variations et cetera.

<div id="videoDiv"></div>

<script type="text/javascript">
    var movieDiv = document.getElementById('videoDiv'),
        movieHtml = '<video id="video" src="../Documents/<%= VideoFileName %>" width="768" height="911"></video>';

    var gotFocus = function () {
        movieDiv.innerHTML = movieHtml;
        var movie = document.getElementById('video');
        movie.play();
        movie.addEventListener('pause', function () {
            movie.currentTime = 0;
            movie.play();
        }, false);
    };
    var lostFocus = function () {
        movieDiv.innerHTML = '';
    };
</script>

解决方案

I finally solved this! The solution was to empty the src and "load" a non-existing video. This causes no memory leak. Have a look:

<div id="videoDiv"></div>

<script type="text/javascript">
    var movieDiv = document.getElementById('videoDiv'),
        movieHtml = '<video id="video" src="" width="768" height="911"></video>';

    movieDiv.innerHTML = movieHtml;
    var movie = document.getElementById('video');

    var gotFocus = function () {
        movie.src = '../Documents/<%= VideoFileName %>';
        movie.load();
        movie.play();
        movie.addEventListener('pause', function () {
            movie.currentTime = 0;
            movie.play();
        }, false);
    };
    var lostFocus = function () {
        movie.src = '';
        movie.load(); // This line may be removed, see comments
    };
</script>

这篇关于加载/卸载HTML5时iOS Safari内存泄漏< video>的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！