iOS无法更改cellforrowatindexpath中图像的角半径

Question

I am trying to round the corners of an image in cellforrowatindexpath like so:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"MyCell";
    MyTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    NSString *identifiers = _identifiers[indexPath.row];

    if([identifier isEqualToString:@"bronze"]){
        cell.imageView.image = [UIImage imageNamed:@"bronze.png"];
        cell.imageView.layer.cornerRadius = cell.imageView.frame.size.width / 2;
        cell.imageView.clipsToBounds = YES;
    }



    return cell;
}

However, this doesn't work. What am I doing wrong?

Answer 1

Try, right after you set your image, calling:

[cell layoutSubviews];

I don't think that this is the best way to do it, but it is a hack that will work. This has been tested.

EDIT (for clarity):

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"MyCell";
    MyTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    NSString *identifiers = _identifiers[indexPath.row];

    if([identifier isEqualToString:@"bronze"]){
        cell.imageView.image = [UIImage imageNamed:@"bronze.png"];
        [cell layoutSubviews];
        cell.imageView.layer.cornerRadius = CGRectGetWidth(cell.imageView.frame) / 2;
        cell.imageView.clipsToBounds = YES;
    } else {
        cell.imageView.image = nil;
        cell.imageView.layer.cornerRadius = 0;
    }

    return cell;
}

Answer 2

The imageView has a frame of (0,0,0,0) at this point. So cell.imageView.frame.size.width is 0. Therefore, your code sets the cornerRadius to 0 again, which is a no-op.

you could hardcode the value for cornerRadius or you could sublass the table view cell and override -layoutSubviews