Question

可能重复：
UIImage in uitableViewcell slowdowns scrolling table

我用plist文件填充了我的表视图数据，该文件将从服务器下载。但是在用户滚动表格之后，滚动速度非常慢！这是我的代码：

    //this is my plist code that load from server 
         NSURL *url = [NSURL URLWithString:@"http://example.com/news.plist"];
         titles = [[NSArray arrayWithContentsOfURL:url] retain];


tableview :

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return titles.count;
    return subtitle.count;
}




    // Customize the appearance of table view cells.
    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {
        static NSString *CellIdentifier = @"Cell";

        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
        }


        tableView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"bg.gif"]];



        // Configure the cell.
        NSUInteger row = [indexPath row]; 
        cell.textLabel.text = [titles objectAtIndex:row];
        cell.textLabel.textColor = [UIColor darkGrayColor];
        cell.textLabel.backgroundColor = [UIColor clearColor];


        cell.detailTextLabel.text = [subtitle objectAtIndex:row]; 
        cell.detailTextLabel.numberOfLines = 6;
        cell.detailTextLabel.backgroundColor = [UIColor clearColor];


        //gradiant BG for cells 
        UIImage *image = [UIImage imageNamed:@"bg2.gif"];
        UIImageView *imageView = [[UIImageView alloc]initWithImage:image];
        imageView.contentMode = UIViewContentModeScaleToFill;
        cell.backgroundView = imageView;
        [imageView release];


        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
        tableView.separatorColor = [UIColor lightTextColor];


        return cell;

    }

感谢您告诉我我的问题是什么

Answer 1

问题很可能是您在bg2.gif内加载图片（例如bg.gif或tableView:cellForRowAtIndexPath:）。我首先尝试在构造函数或表视图控制器的单独方法中加载这些图像，将它们存储在实例变量中，然后在需要时重新使用它们。

Answer 2

放手一搏：

- (void) viewDidLoad {
   [super viewDidLoad];

   tableView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"bg.gif"]];
   tableView.separatorColor = [UIColor lightTextColor];
} 


// Customize the appearance of table view cells.
    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];

        // Do all your desgin settings here, not if the cell gets dequeued.
        cell.textLabel.textColor = [UIColor darkGrayColor];
        cell.textLabel.backgroundColor = [UIColor clearColor];

        //gradiant BG for cells 
        UIImage *image = [UIImage imageNamed:@"bg2.gif"];
        UIImageView *imageView = [[UIImageView alloc]initWithImage:image];
        imageView.contentMode = UIViewContentModeScaleToFill;
        cell.backgroundView = imageView;
        [imageView release];

        cell.detailTextLabel.numberOfLines = 6;
        cell.detailTextLabel.backgroundColor = [UIColor clearColor];
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    }

   // Configure the cell.
    NSUInteger row = [indexPath row]; 
    cell.textLabel.text = [titles objectAtIndex:row];
    cell.detailTextLabel.text = [subtitle objectAtIndex:row]; 

    return cell;

}

Answer 3

删除tableView中- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath的所有函数/方法调用，您应该在tableView或-viewDidLoad中配置-loadView。

为了提高滚动速度，建议您查看以下内容：http://blog.atebits.com/2008/12/fast-scrolling-in-tweetie-with-uitableview/。

慢速滚动UITableView

3 个答案: