UITableView重用导致破碎的细胞

Question

When scrolling my UITableView (tends to be when I scroll it fast) the data for my cells gets mixed up, so labels might be repeated etc.

I understand that reusing the cells probably causes this, but what if the user scrolls down the list really quickly and all the cells get mixed up, how am I supposed to avoid this?

Thanks.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"VideoListCell";
    VideoListCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

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

    // Configure the cell...
    if (isPlaylistView)
    {
        //Fill cell with data
    }
    else if (isPlaylistDetailView || isSearchResultsView)
    {
        //Fill cell with data
    }
    else
    {
        //Playlist button and uploads
        if (indexPath.section == 0)
        {
            //Fill cell with data
        }
        else
        {
            //Fill cell with data
        }
    }

    return cell;
}

Answer 1

You generally use this kind of code:

cell = dequeReusableCell;
if (cell == nil) { 
    create cell;
    initialize cell;
}

fill cell with actual data from current row
return cell;

If you will move code "fill cell with actual data from current row" into "if" — you will get the kind of behavior you get right now.

So the answer will be "fill cell with data after you initialize it, outside of "if (cell == nil)" block.

Answer 2

UITableView will ever only dequeue a cell for reuse if the position that the cell was in is currently off-screen. So you don't have to worry about "mix-ups".

Answer 3

static NSString *cellIdentifier=@"cell";
    UITableViewCell *cell=[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if(cell==nil)
    {
        cell=[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:nil];
    }

I think it will be helpful to you.

Answer 4

set dequeueReusableCellWithIdentifier to nil for example..

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:nil];

UPDATE:

See this Example... i load many data in the cell with also my custom Gridview...

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

    UITableViewCell *gridCell = [tableView dequeueReusableCellWithIdentifier:nil];

    if(gridCell == nil)        
    {
        gridCell =  [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];


    }
    return gridCell;
}

hope this help you....

Answer 5

In your custom cell class override prepareForReuse method. In this method set text of your labels to nil and set imageview's image to nil also. This function is called everytime when a cell is reused so your problem will be solved by this. May be like this

- (void)prepareForReuse{
    [super prepareForReuse];
    self.titleLabel.text = nil;
    self.unitImageView.image = nil;
}