先將JSON串轉換成NSString，再轉化為NSData，後再轉為NSDictionary，再取出其中的NSArray，最後獲取所需NSDictionary元素值：

- (void)parseJSON: (void *)param1 {
    const char *p_json = NULL;

    if (param1) {
        p_json = param1;
        //NSLog(@"p_json: %s", p_json);
        
        NSString *pauseAdJson = [[NSString alloc] initWithUTF8String:p_json];
        //NSLog(@"pauseAdJson: %@", pauseAdJson);
        
        //json解析
        NSData *jsonData = [pauseAdJson dataUsingEncoding:NSUTF8StringEncoding];
        //NSLog(@"jsonData: %@", jsonData);
        
        NSError *err;
        
        NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:jsonData
                                                            options:NSJSONReadingMutableContainers
                                                              error:&err];
        
        if(err) {
            NSLog(@"json解析失敗：%@",err);
        }
        //NSLog(@"jsonDict: %@", jsonDict);
        
        NSArray *pauseAdArray = [jsonDict objectForKey:@"pause_ad"];
        //NSLog(@"pauseAdArray: %@", pauseAdArray);
        
        NSURL *pauseAdImageUrl = [NSURL URLWithString: [[pauseAdArray objectAtIndex:0] objectForKey:@"url"]];
        
        // UI的操作必須要到主執行緒做
        [self performSelectorOnMainThread:@selector(pauseAdDownloadandView:) withObject:pauseAdImageUrl waitUntilDone:NO];

    }
}

- (void)pauseAdDownloadandView: (NSURL *)imageUrl {
    //在playerview中心展現，佔playerview一半的大小
    CGRect pauseAdViewRect = CGRectMake([playerview bounds].size.width/4, 
                                        [playerview bounds].size.height/4, 
                                        [playerview bounds].size.width/2, 
                                        [playerview bounds].size.height/2);
    
    pauseAdView = [[UIImageView alloc] initWithFrame:pauseAdViewRect];
    pauseAdView.layer.masksToBounds = YES;
    pauseAdView.layer.cornerRadius = 5.0f;
    [pauseAdView setBackgroundColor:[UIColor blackColor]];
    
    UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:imageUrl]];
    pauseAdView.image = image;
    
    [playerview addSubview:pauseAdView];
}