heightForRowAtIndexPath with custom cell and label [duplicate]

Question

This question already has answers here:

Calling heightForRowAtIndexPath from within cellForRowAtIndexPath? (3 answers)

Closed 9 years ago.

If I'm making a custom UITableViewCell and I need it to have a variable height depending on the length of the input (for instance, for a Twitter reader or something), how can I make this work?

I've found lots of other examples here that can set it for a the standard, non-custom cell, but my cell's main text label is smaller, etc., so when I try to use any of those methods on my cell, they give a variety of weird results (text overlapping the bottom of the cell, etc.)

Is there a standardized way of designing the cell (for example, how tall should I make it in Interface Builder?), and let's say my label was half the width of that cell.. how would I go about calculating the height the cell would need to be to display the string loaded into that label? Here's a method that I found here which works fine on the normal cell, but screws up custom ones with weird heights, overlapping text, etc: (I have absolutely NO idea what the 300 / 200000 do here, if anyone could explain that I'd be grateful, too!)

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    CGSize  textSize = {300.f, 200000.0f};
    CGSize  size = [[_quoteStringsFromPlist objectAtIndex: indexPath.row] sizeWithFont: [UIFont systemFontOfSize:12.0f] constrainedToSize: textSize lineBreakMode: NSLineBreakByWordWrapping];
    size.height += 5.0f;
    float result = MAX(size.height, 32.0f);
    return result;
}

Answer 1

Something like this should work.

CGRect labelFrame = // enter default frame of the label here
UIFont *labelFont = // enter label font here
CGFloat labelBottomMargin = // enter the space between the bottom of the label and the bottom of the cell here

CGSize  size = [labelString sizeWithFont:labelFont constrainedToSize:CGSizeMake(labelFrame.size.width, MAX_FLOAT)];
size.height += labeFrame.origin.y;
size.height += labelBottomMargin;
size.height = MAX(size.height, 32.0f);
return size.height;

Answer 2

First, head over to your xib file and see how large are the top/bottom margins of your text area, and how wide it is.

After that, you need to calculate the height needed for it with the width you have available, and then add that value to the top/bottom margins your text area already has.

The result should look correctly regardless of the size of each cell in IB or the text you are trying to put in them.

EDIT

Imagine your cell size is {700, 300} in your IB, and your text area is located on {{100, 100}, {300,100}}, your text area has a 100px margin top and 100px margin bot, and it's width is 300.

When you calculate the height you require for your text, you calculate it with an available 300 width. It will return a size, something like {300, 250}. That 250 is the height required by your text, but your cell has other stuff in it and you need to add those top and bot margins to that, so the result is 450.

Remember to set an autoresizing mask or autolayout so that your text area stretches vertically and the margins are fixed (UIViewAutoresizingFlexibleHeight)