UIWebView加载html5-Video EXC_BAD_ACCESS崩溃 [英] UIWebView loading html5-Video EXC_BAD_ACCESS crash
问题描述
在我们的iPad-App中，我们使用UIWebView从一个域加载不同的站点，其中一些使用hml5-Video加载。
没有视频的网站可以完美加载。但是当我加载一个包含htmlt5-video的网站时，有时我的app
会在使用EXC_BAD_ACCESS的UIWebView加载过程中崩溃，有时却不会。每当发生这样的崩溃时，似乎发生在将视频播放器添加到站点中的位置。
in our iPad-App we are using an UIWebView to load different sites from one domain some of them with a hml5-Video. Sites without a Video do load perfectly. But when I'm loading a site containing htmlt5-video sometimes my app crashes during the loading-process of the UIWebView with EXC_BAD_ACCESS and sometimes it does not. Whenever such a crash occurs it seems to happen at the point where the Video-Player is added into the site.
我确实从Apple下载了UICatalog-Example，并且确实将WebViewController-Class中的Default-URL更改为包含html5-video的站点的URL。相同的结果...有时崩溃有时不会崩溃。
I did download the UICatalog-Example from Apple and just did change the Default-URL in the WebViewController-Class to a URL of a site containg html5-video. Same results ... sometimes crash sometimes no crash.
我还在Xcode上创建了一个新项目（基于视图的应用程序 - 用于iPad）并且只添加了一个UIWebView到新的Projects ViewController。再次......加载包含html5-video的网站有时会导致崩溃，有时也不会。
I also did create a New Project on Xcode (View-based Application - for iPad) and only did add a UIWebView to the new Projects ViewController. Again ... loading a site containing html5-video sometimes leads to a crash and sometimes not.
来自新项目的代码视图控制器（实施）：
CODE FROM "NEW PROJECTS" VIEWCONTROLLER (IMPLEMENTATION):
- (void)viewDidLoad {
[super viewDidLoad];
self.myWebView = [[[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 768, 1004)] autorelease];
self.myWebView.backgroundColor = [UIColor whiteColor];
self.myWebView.scalesPageToFit = YES;
self.myWebView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
self.myWebView.delegate = self;
[self.view addSubview: self.myWebView];
[self.myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.gelbeseiten.de/129103114849"]]];
//More Sites with HTML5-Videos ...
//[self.myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.gelbeseiten.de/129103746403"]]];
//[self.myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.gelbeseiten.de/129105233646"]]];
}
- (void)viewDidUnload {
[super viewDidUnload];
self.myWebView = nil;
}
- (void)viewWillDisappear:(BOOL)animated {
[self.myWebView stopLoading];
}
- (void)dealloc {
myWebView.delegate = nil;
[myWebView release];
[super dealloc];
}
代码来自新项目VIEWCONTROLLER（HEADER）：
CODE FROM "NEW PROJECTS" VIEWCONTROLLER (HEADER):
@interface WebViewTestViewController : UIViewController <UIWebViewDelegate> {
UIWebView *myWebView;
}
@property (nonatomic, retain) UIWebView *myWebView;
设备日志：
Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00000098
Crashed Thread: 0
Thread 0 Crashed:
0 WebCore 0x34c7d09e WebCore::RenderLayer::clippingRoot() const + 110
1 WebCore 0x34c7cf2a WebCore::RenderLayer::childrenClipRect() const + 26
2 WebCore 0x34c7ce0c WebCore::RenderWidget::setWidgetGeometry(WebCore::IntRect const&) + 40
3 WebCore 0x34c5e0f8 WebCore::RenderWidget::updateWidgetPosition() + 320
4 WebCore 0x34ba0170 WebCore::RenderView::updateWidgetPositions() + 144
5 WebCore 0x34b97d16 WebCore::FrameView::performPostLayoutTasks() + 202
6 WebCore 0x34b8a6c0 WebCore::FrameView::layout(bool) + 2116
7 WebCore 0x34bc5244 WebCore::FrameView::forceLayout(bool) + 4
8 WebKit 0x302c0c24 -[WebHTMLView layoutToMinimumPageWidth:height:maximumPageWidth:adjustingViewSize:] + 136
9 WebKit 0x302c0b8e -[WebHTMLView layout] + 18
10 WebKit 0x302c26f2 -[WebHTMLView(WebInternal) _layoutIfNeeded] + 50
11 WebKit 0x302c2622 -[WebHTMLView(WebInternal) _web_layoutIfNeededRecursive] + 14
12 WebKit 0x302c251e -[WebHTMLView(WebPrivate) viewWillDraw] + 50
13 CoreFoundation 0x3581dfc0 -[NSObject(NSObject) performSelector:] + 12
14 CoreFoundation 0x35826d4a -[NSArray makeObjectsPerformSelector:] + 382
15 WebCore 0x34bb000c -[WAKView viewWillDraw] + 24
16 CoreFoundation 0x3581dfc0 -[NSObject(NSObject) performSelector:] + 12
17 CoreFoundation 0x35826d4a -[NSArray makeObjectsPerformSelector:] + 382
18 WebCore 0x34bb000c -[WAKView viewWillDraw] + 24
19 CoreFoundation 0x3581dfc0 -[NSObject(NSObject) performSelector:] + 12
20 CoreFoundation 0x35826d4a -[NSArray makeObjectsPerformSelector:] + 382
21 WebCore 0x34bb000c -[WAKView viewWillDraw] + 24
22 CoreFoundation 0x3581dfc0 -[NSObject(NSObject) performSelector:] + 12
23 CoreFoundation 0x35826d4a -[NSArray makeObjectsPerformSelector:] + 382
24 WebCore 0x34bb000c -[WAKView viewWillDraw] + 24
25 WebKit 0x302c24cc -[WebView(WebPrivate) viewWillDraw] + 56
26 WebCore 0x34bafec0 WebCore::TileCache::prepareToDraw() + 36
27 WebCore 0x34bafe6e -[TileLayer display] + 26
28 QuartzCore 0x31079fb0 CALayerDisplayIfNeeded + 176
29 QuartzCore 0x3106f56e CA::Context::commit_transaction(CA::Transaction*) + 214
30 QuartzCore 0x3106f37c CA::Transaction::commit() + 184
31 QuartzCore 0x31092f96 CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 46
32 CoreFoundation 0x3580ac52 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 10
33 CoreFoundation 0x3580aac6 __CFRunLoopDoObservers + 406
34 CoreFoundation 0x358020c4 __CFRunLoopRun + 848
35 CoreFoundation 0x35801c80 CFRunLoopRunSpecific + 224
36 CoreFoundation 0x35801b88 CFRunLoopRunInMode + 52
37 GraphicsServices 0x320c84a4 GSEventRunModal + 108
38 GraphicsServices 0x320c8550 GSEventRun + 56
39 UIKit 0x341dc322 -[UIApplication _run] + 406
40 UIKit 0x341d9e8c UIApplicationMain + 664
41 WebViewTest 0x00002c24 0x1000 + 7204
42 WebViewTest 0x00002bd8 0x1000 + 7128
有人可以给我一个想法吗？
Can anybody give me an idea?
提前致谢，Florian
Thanks in advance, Florian
推荐答案
有一个小技巧可以覆盖这次崩溃。如果您在加载视频内容之前稍微滚动webview，则可以避免崩溃。在从代码中尝试之前，尝试用手指在设备上滚动webView。它现在不会崩溃。
There is a little trick to override this crash. If you slightly scroll the webview just before the video content is loaded, the crash can be avoided. Before trying it out from code, try scrolling the webView a bit on device with your finger. It won't crash now.
在代码中，执行以下操作：
In code, do something like this:
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
[webView stringByEvaluatingJavaScriptFromString:@"window.scrollTo(0, 10);"];
}
通过javascript模拟webview上的滚动。滚动值可以低至1，因此用户根本不会注意到滚动。
to simulate a scroll on the webview through javascript. The scroll value can be as low as 1, so the user won't notice the scroll at all.
这篇关于UIWebView加载html5-Video EXC_BAD_ACCESS崩溃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！
