Adding a UIButton to a UICollectionView cell programmatically

问题

I have a UIViewController with a UICollectionView created inside it programmatically. I want to add a button to the cell:

viewDidLoad:

UICollectionViewLayout *layout = [[UICollectionViewFlowLayout alloc]init];
_collectionView = [[UICollectionView alloc]initWithFrame:self.view.bounds collectionViewLayout:layout];

    [_collectionView setDataSource:self];
    [_collectionView setDelegate:self];

    [_collectionView registerClass:[EMCell class] forCellWithReuseIdentifier:@"Cell"];

    [self.view addSubview:_collectionView];

And then:

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    EMCell *cell = (EMCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];

    cell.backgroundColor = [UIColor greenColor];

    UIButton *button = (UIButton *)[cell viewWithTag:200];
    [button setFrame:CGRectMake(10, 10, 50, 60)];
    [button setTitle:@"Button" forState:UIControlStateNormal];

    [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];

    [cell addSubview:button];
    return cell;
}

What am I doing wrong?

回答1:

Add your button as a subview of cell.contentView. Also, don't create the button every time collectionView:cellForItemAtIndexPath: is called. You might be reusing an existing cell that already has a button. Better to add the button in your custom cell's init method instead. Then just hide the button when you don't need it.

来源：https://stackoverflow.com/questions/17843533/adding-a-uibutton-to-a-uicollectionview-cell-programmatically