Question

现在我正在使用uitableview，其中包含在uibutton上设置的用户图像，在mpmovieplayercontroller上录制的视频播放就像藤蔓应用程序一样。

这里我的问题是当从一行到另一行时，uitableview不能平滑滚动。

我不知道为什么会这样。任何人都知道原因为如何解决这类问题提供了一些指导。

我在这里从网络服务获取数据。

    -(void)feedwebservice
{

    NSString *myurl1=[NSString stringWithFormat:@"http://demo.xyz.com/client/vine-clone/feed/home_feed?user_id=%@&start=%d",AppDelegate.check,navigate];
    NSString  *theurl1=[myurl1 stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSMutableURLRequest *theRequest1=[NSMutableURLRequest requestWithURL:[NSURL URLWithString:theurl1]cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
    NSHTTPURLResponse *response; 
    NSError* error12;
    NSData *data1=[NSURLConnection sendSynchronousRequest:theRequest1 returningResponse:&response error:&error12];
    NSString *strResponse1=[[NSString alloc]initWithData:data1 encoding:NSUTF8StringEncoding];
    NSMutableString* responseString = [NSMutableString stringWithString:strResponse1];
    SBJSON *parser = [[SBJSON alloc] init];
    NSDictionary *dic1 = [parser objectWithString:responseString error:nil];
    for(NSDictionary *subDic in dic1)
    {
        obj=[[DataSet alloc]init];
        obj.data1=[subDic objectForKey:@"channel"];
        obj.data2=[subDic objectForKey:@"followers"];
        obj.data3=[subDic objectForKey:@"following"];
        obj.data4=[subDic objectForKey:@"fullname"];
        obj.data5=[subDic objectForKey:@"post_private"];
        obj.data6=[subDic objectForKey:@"post_sensitive"];
        obj.data7=[subDic objectForKey:@"profile_image"];
        obj.data8=[subDic objectForKey:@"status"];
        obj.data9=[subDic objectForKey:@"title"];
        obj.data10=[subDic objectForKey:@"total_like"];
        obj.data11=[subDic objectForKey:@"total_vine"];
        obj.data12=[subDic objectForKey:@"user_id"];
        obj.data13=[subDic objectForKey:@"user_like"];
        obj.data14=[subDic objectForKey:@"user_vine"];
        obj.data15=[subDic objectForKey:@"video_created_date"];
        obj.data16=[subDic objectForKey:@"video_id"];
        obj.data17=[subDic objectForKey:@"video_name"];
        [feedarr addObject:obj];

}
    //NSLog(@"feedpage count = %u",[feedarr count]);
    [videotable reloadData];
    [pullToRefreshManager_ tableViewReloadFinished];

}

uitableview单元格用于索引路径行的数据

    -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    /*if(cell == nil)
     {
     }*/

    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                  reuseIdentifier:CellIdentifier];

    obj=[feedarr objectAtIndex:indexPath.row];

    profileimgbtn = [UIButton buttonWithType:UIButtonTypeCustom];
    [profileimgbtn setFrame:CGRectMake(10, 280, 50, 40)];
    [profileimgbtn setBackgroundColor:[UIColor clearColor]];


    [profileimgbtn setBackgroundImage:[UIImage imageNamed:@"Placeholder.png"] forState:UIControlStateNormal];
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
    dispatch_async(queue, ^{
        obj.data7 = [obj.data7 stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
        NSURL *imageURL = [NSURL URLWithString:obj.data7];
        NSURLRequest *request = [NSURLRequest requestWithURL:imageURL];
        NSError *error;
        NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:&error];
        UIImage *image = [[UIImage alloc] initWithData:data];
        dispatch_async(dispatch_get_main_queue(), ^{
            [profileimgbtn setBackgroundImage:image forState:UIControlStateNormal];
        });
    });

    [cell addSubview:profileimgbtn];

    playerview = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 300, 250)];
    [playerview setBackgroundColor:[UIColor orangeColor]];
    [cell addSubview:playerview];

    obj.data17 = [obj.data17 stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    NSURL *contentURL = [NSURL URLWithString:[NSString stringWithFormat:@"%@",obj.data17]];
    mc = [[MPMoviePlayerController alloc] initWithContentURL:contentURL];

    mc.shouldAutoplay = YES;
    mc.controlStyle = MPMovieControlStyleNone;
    mc.contentURL = contentURL;
    [mc prepareToPlay];
    mc.repeatMode=MPMovieRepeatModeOne;
    mc.view.frame = playerview.bounds;
    [mc setScalingMode:MPMovieScalingModeFill];
    [mc play];
    [playerview addSubview:mc.view];


    //Get the image from the currentPlaybackTime to set it above the player
    thumbnail = [mc thumbnailImageAtTime:[mc currentPlaybackTime] timeOption:MPMovieTimeOptionNearestKeyFrame];
    thumbnailView = [[UIImageView alloc] initWithFrame:mc.view.frame];
    [thumbnailView setImage:thumbnail];
    [thumbnailView setContentMode:UIViewContentModeScaleToFill];
    thumbnailView.clipsToBounds = YES;
    [playerview addSubview:thumbnailView];

    singleFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleRollTap:)];
    [singleFingerTap setDelegate:self];
    singleFingerTap.numberOfTouchesRequired=1;
    singleFingerTap.numberOfTapsRequired=1;
    [mc.view addGestureRecognizer:singleFingerTap];
    self.moviePlayerController = mc;

    playerActivityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    playerActivityIndicator.frame = CGRectMake(140, 110, 25, 25);
    [playerActivityIndicator startAnimating];
    [playerview addSubview:playerActivityIndicator];
    [self performSelector:@selector(spinnerhide) withObject:nil afterDelay:5.0];

    cell.selectionStyle=UITableViewCellSelectionStyleNone;

    return cell;
}

Answer 1

您似乎已经注释掉了单元格重用 - 这是一个惊人的性能保存功能，用于限制创建的单元格数量，从而限制系统征税的数量。

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if(cell == nil)
{
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                              reuseIdentifier:CellIdentifier];
}

obj=[feedarr objectAtIndex:indexPath.row];

...

Answer 2

您可以从互联网添加EgoImagebuton文件：https://github.com/enormego/EGOImageLoading

然后，使用egoimagebuton代替UIImageView。

Answer 3

这真的很糟糕，你不应该每次都创建单元格：

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

/*if(cell == nil)
 {
 }*/

cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                              reuseIdentifier:CellIdentifier];

应该是：

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if(cell == nil)
{
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                  reuseIdentifier:CellIdentifier];
}

Answer 4

除了按照其他答案中的建议重新使用单元格之外，还需要确保在完成处理程序中，通过向表视图发送返回单元格的相应消息，将再次显式获取分配图像的单元格。基于 indexPath 。

您需要这样做的原因是，一旦您重复使用单元格，并且一旦执行完成处理程序，该单元格就不再像以前那样与indexPath相关联。

因此，在您的完成处理程序中，根据indexPath重新获取单元格：

dispatch_async(dispatch_get_main_queue(), ^{
    MyTableViewCell* cell = (MyTableViewCell*)[tableView cellForRowAtIndexPath:indexPath];
    [cell.addProfileImagegButton setBackgroundImage:image forState:UIControlStateNormal];
});

在这里，假设您已将UITableViewCell子类化为属性profileImagegButton。

此外，如果发生该单元格不再可见，cellForRowAtIndexPath:将返回nil。

但是，完整的解决方案要求您实现图像缓存，并且当当前存在具有相同URL挂起的请求时，还要阻止加载URL。在设置占位符图像之前，您需要检查缓存是否有图像。

UITableview在每一行出现之前都不能顺畅滚动？

4 个答案: