ios – NSURLProtocol canInitWithRequest：仅适用于某些请求

我有@L_616_1@WebView,我想@L_675_2@和修改来自不同站点的某些请求.我对每个截获的请求进行完全相同的修改,无论它来自哪个站点.由于看似没有理由,它适用于除了@L_616_1@以外的每个站点.这是我的代码：

在我的resourceLoadDelegate中

- (NSURLrequest *)webView:(WebView *)sender resource:(id)identifier willSendrequest:(NSURLrequest *)request redirectResponse:(NSURLResponse *)redirectResponse fromDatasource:(WebDatasource *)datasource
{
    //preDicates
    const NSPreDicate *site1PreDicate = [NSPreDicate preDicateWithFormat:@"SELF like \"/*preDicate1*/""];
    const NSPreDicate *site2PreDicate = [NSPreDicate preDicateWithFormat:@"SELF like \"/*preDicate2*/""];
    const NSPreDicate *site3PreDicate = [NSPreDicate preDicateWithFormat:@"SELF like \"/*preDicate3*/""];
    const NSPreDicate *site4PreDicate = [NSPreDicate preDicateWithFormat:@"SELF like \"/*preDicate4*/""];
    const NSPreDicate *site5PreDicate = [NSPreDicate preDicateWithFormat:@"SELF like \"/*preDicate5*/""];

    //preDicate arrays
    const NSArray *songPreDicates = [NSArray arrayWithObjects:site1PreDicate,site2PreDicate,site3PreDicate,site4PreDicate,site5PreDicate,nil];

    //site is an int with its defined in an enum
    if ([[songPreDicates objectATindex:site-1] evaluateWithObject:request.URl.host])
    {
        NSMutableURLrequest* newrequest = [request mutableCopy];
        [InterceptionProtocol setProperty:self forKey:@"MyApp" inrequest:newrequest];
        dispatch_async( dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0),^{
            /* Do stuff */
        });
        return newrequest;
    }
    return request;
}

在InterceptionProtocol.m中

+ (BOOL) canInitWithrequest:(NSURLrequest*)request
{
    id delegate = [NSURLProtocol propertyForKey:@"MyApp" inrequest:request];
    if (delegatE) NSLog(@"Can init: %@",request);
    return (delegate != nil);
}

出于某种原因,除了站点4之外,这对于除了站点4之外的所有内容都非常有效.我已经完成了代码并且我知道谓词正确匹配.我不知道这对其他网站有什么用,但不是这个.有任何想法吗？

编辑

完整的源代码可以在这里找到：
http://github.com/garrett-davidson/iLikeMusic