在点击识别器上识别表格单元格

Question

I have a tableview in my View. The cells are created using custom Cells. I need to display a large string in the table view cells So I had added the text Label in a Scrollview. Also I need to execute some code when the user taps on table view cell. Please see the below code:

 [cell.textLabelLine2 setFrame:CGRectMake(cell.textLabelLine2.frame.origin.x, cell.textLabelLine2.frame.origin.y, 500, cell.textLabelLine2.frame.size.height)];
   cell.scrollView.contentSize = CGSizeMake(cell.textLabelLine2.text.length*10 , 10);
   cell.scrollView.pagingEnabled = NO;

The problem is when the user touches above the Scroll View, the Tableview did select method will not be called. The solution I found for this problem is to add a gesture recogniser to the scroll view. But in this solution, we have no ways to check which cell(or which gesture recogniser) was selected. Could anyone help me to find a solution for this problem?

Answer 1

You can get to know the cell by the following code

if(gestureRecognizer.state == UIGestureRecognizerStateBegan) {
    CGPoint p = [gestureRecognizer locationInView:[self tableView]];

    NSIndexPath *indexPath = [[self tableView] indexPathForRowAtPoint:p];

    if(indexPath != nil) {

        UITableViewCell *cell = [[self tableView] cellForRowAtIndexPath:indexPath];

                    ...
    }
}

Answer 2

It's generally a bad idea putting scroll views inside scroll views. UITableView is also just a UIScrollView. That only kind of works if they are scrolling on different axis, ie the outer scroll view scrolling vertically and the inner scrolling horizontally.

For your specific scenario you would have to trigger the selection yourself. Once you have a reference to the cell you can ask the table view for the indexPath of it. Then you would call the delegate method for didSelectRow... yourself.

Answer 3

In the solution with the scrollview you are not able to scroll in the scrollview because the gestureRecognizer 'gets' the touch. Therefor I would not use the scrollview at all.

Make the label resize to its content like:

    CGSize customTextLabelSize = [cell.customTextLabel.text sizeWithFont:cell.customTextLabel.font constrainedToSize:CGSizeMake(cell.customTextLabel.frame.size.width, 999999)];
    cell.customTextLabel.frame = CGRectMake(cell.customTextLabel.frame.origin.x, cell.customTextLabel.frame.origin.y, cell.customTextLabel.frame.size.width, customTextLabelSize.height);

You also need to implement this in the heightForRowAtIndexPath

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
    CGSize cellSize = [bigTextString sizeWithFont:customTextLabel.font constrainedToSize:CGSizeMake(generalCellWidth, 999999)];
    return cellSize.height;
}

This way you can just use the didSelectRowAtIndex method.

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If you really want to use the scrollview, add a button to your cell in the cellForRowAtIndexPath: method. Make the button just as big as the cell and add a button tag like this:

    UIButton *cellButton = [UIButton buttonWithType:UIButtonTypeCustom];
    cellButton.frame = CGRectMake(0, 0, cell.frame.size.width, cell.frame.size.height);
    cellButton.tag = indexPath.row;
    [cellButton addTarget:self action:@selector(cellButtonAction:) forControlEvents:UIControlEventTouchUpInside];
    [cell.contentView addSubview:cellButton];

Then add:

-(void)cellButtonAction:(UIButton*)sender
{
    //do something with sender.tag
}