在HTML5文档中加载视频时,WebView的自定义NSURLProtocol类不起作用

我正在使用WebView,它从沙盒等特定位置加载其内容.所以我添加了NSURLProtocol的简单子类来处理这些文件.协议处理程序将管理URL方案,如"dummy:".当我尝试像dummy:///index.html这样的自定义URL时,这应该从本地目录加载index.html.Htmls和嵌入式图像等工作正常.

但是当我尝试使用包含HTML5视频播放器的html文件时,它不起作用.WebView甚至没有尝试过canInitWithRequest方法:在我的自定义类中请求视频文件.

@interface DummyURLProtocol : NSURLProtocol {
}

+ (BOOL)canInitWithRequest:(NSURLRequest *)request;
+ (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request;
+ (BOOL)requestIsCacheEquivalent:(NSURLRequest *)a toRequest:(NSURLRequest *)b;
- (void)startLoading;
- (void)stopLoading;

@end

@implementation DummyURLProtocol

+(BOOL)canInitWithRequest:(NSURLRequest *)request {
    return [[[request URL] scheme] isEqualToString:@"dummy"];
}

+(NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request {
    return request;
}

+(BOOL)requestIsCacheEquivalent:(NSURLRequest *)a toRequest:(NSURLRequest *)b {
    return [[[a URL] resourceSpecifier] isEqualToString:[[b URL] resourceSpecifier]];
}

-(void)startLoading {
    NSURL *url = [[self request] URL];
    NSString *pathString = [url resourceSpecifier];
    NSString *path = [NSString stringWithFormat:@"/Users/cronos/tmp/video_demo/%@", pathString];
    NSString *fullFilename = [pathString lastPathComponent];
    NSString *extention = [fullFilename pathExtension];
    NSString *mimeType = [[SSGHTMLUtil sharedUtil] mimeTypeForExtension:extention];
    NSLog(@"DummyURLProtocol:FILEPATH: %@ EXTENSION: %@ MIME-TYPE: %@", path, extention, mimeType);


    NSURLResponse *response = [[NSURLResponse alloc] initWithURL:url MIMEType:mimeType expectedContentLength:-1 textEncodingName:nil];
    FILE *fp = fopen([path UTF8String], "r");
    if (fp) {
        char buf[32768];
        size_t len;
        [[self client] URLProtocol:self
                didReceiveResponse:response
                cacheStoragePolicy:NSURLCacheStorageNotAllowed];
        while ((len = fread(buf,1,sizeof(buf),fp))) {
            [[self client] URLProtocol:self didLoadData:[NSData dataWithBytes:buf length:len]];
        }
        fclose(fp);
    }
    [[self client] URLProtocolDidFinishLoading:self];
}

-(void)stopLoading {
}

@end

我在AppDlegate.m中的applicationDidFinishLaunching中注册了协议处理程序

if ([NSURLProtocol registerClass:[DummyURLProtocol class]]) {
    NSLog(@"URLProtocol registration successful.");
} else {
    NSLog(@"URLProtocol registration failed.");
}

然后我用网址"dummy:///HTML5_Video.html"尝试了我的WebView.其他资源如javascript文件,css文件,图像都已成功加载,但mp4文件未传递给DummyURLProtocol.HTML5_Video.html包含以下内容.

有什么想法或好的出发点来解决这个问题？

谢谢.

对.它不会起作用.

我在一年多前就向苹果公司提出了漏洞.

视频和其他多媒体类型(包括SVG)不通过NSURLProtocol机制

见http://openradar.appspot.com/8446587

和http://openradar.appspot.com/8692954