tableview dequeue reusable cell overlaps

Question

I have a custom table view cell class. I dynamically create uiviews and uilabels and uiimageview to cell and alloc and init them with frame.contentView. But on scroll because of reuse they get overlapped and label's text and other properties get overlapped.

Answer 1

If you reuse cells, you almost entirely responsible for resetting their content before reuse. This is a problem that is still not sufficiently explained in the SDK documentation, in my opinion.

That means, after calling [dequeueReusableCellWithIdentifier], you should do things like:

1) Set/Reset color, font, and text on textLabel and detailTextLabel, if you ever touch these.

2) Adjust accessoryType.

3) Adjust frame and backgroundColors.

4) Remove all non-standard subviews. I usually code like this:

for (UIView *subView in cell.contentView.subviews) {
    if (subView == cell.textLabel) continue;
    if (subView == cell.imageView) continue;
    if (subView == cell.detailTextLabel) continue;
    [subView removeFromSuperview];
}

And so on. Anything that can get touched for a particular reuse identifier should be reset to a zero-state.

Answer 2

Check rowsize of table and row size of custom cell should be same to get proper view.

Check and alloc cell like this after reuse of tabeview cell.

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

   UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellIdentifier];
    NSLog(@"cai no init da cell");
// change style according to yours..
}

return cell

}

Answer 3

It sounds like you are adding child views to the cell inside the tableview:cellForRowAtIndexPath: method. As the cells are being reused, the views from a previous use already exist in the cell, and you are ignoring those new views and just adding more.

The correct way is to add the views during the initialisation of the cell, then just set the values of the views in the tableview:cellForRowAtIndexPath: method.

You should use a custom class inheriting from UITableViewCell and create properties for the views you want to add (so they can be accessed in tableview:cellForRowAtIndexPath:). You can then either add the views in the init call for the custom class, or use an XIB or prototype cell to add the views and hook them up to the properties as IBOutlets.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    MyModelObject* myObject = myObjects[indexPath.row];

    if (myObject.images.count == 1) {
        MyCustomTableViewCellOne *cell = (MyCustomTableViewCellOne*) [self.tableView dequeueReusableCellWithIdentifier:@"MyCustomTableViewCellOneIdentifer" forIndexPath:indexPath]; 

        cell.title = @"Some item";
        cell.imageView.image = [UIImage imageNamed:@"image.png"];
        return cell;
    } else {
        MyCustomTableViewCellTwo *cell = (MyCustomTableViewCellTwo) [self.tableView dequeueReusableCellWithIdentifier:@"MyCustomTableViewCellTwoIdentifer" forIndexPath:indexPath]; 

        cell.title = @"Some item";
        cell.imageView.image = [UIImage imageNamed:@"image.png"];
        cell.imageView2.image = [UIImage imageNamed:@"image2.png"];
        return cell;
    }
}

MyCustomTableViewCellOne.h:

@interface MyCustomTableViewCellOne : UITableViewCell

@property (strong, nonatomic) IBOutlet UILabel *title;
@property (strong, nonatomic) IBOutlet UIImageView *imageView;

@end

MyCustomTableViewCellTwo.h:

@interface MyCustomTableViewCellTwo : UITableViewCell

@property (strong, nonatomic) IBOutlet UILabel *title;
@property (strong, nonatomic) IBOutlet UIImageView *imageView;
@property (strong, nonatomic) IBOutlet UIImageView *imageView2;

@end

Answer 4

Finally solved the problem by using tag for each subview. After getting the view by tag from it's parent view, if view is not present only then I reallocate and addSubView. This solved the issue.