UITableViewAutomaticDimension not working until scroll

问题

When the Table View is first loaded, all of the visible cells are the estimatedRowHeight. As I scroll down, the cells are being automatically sized properly, and when I scroll back up the cells that were initially estimatedRowHeight are being automatically sized properly.

Once the cells are being automatically sized, they don't ever seem to go back to being the estimatedRowHeight.

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)
    self.tableView.estimatedRowHeight = 80.0
    self.tableView.rowHeight = UITableViewAutomaticDimension

    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem()
}

and

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cellIdentifier = "Cell"
    let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as CustomTableViewCell

    // Configure the cell...
    let restaurant = restaurants[indexPath.row]
    cell.namelabel.text = restaurant.name
    cell.locationlabel.text = restaurant.location
    cell.typelabel.text = restaurant.type
    cell.thumbnailImageView.image = UIImage(named: restaurant.image)
    cell.thumbnailImageView.layer.cornerRadius = cell.thumbnailImageView.frame.size.width / 2
    cell.thumbnailImageView.clipsToBounds = true
    cell.accessoryType = restaurant.isVisited ? .Checkmark : .None

    return cell
}

Thoughts on how to have the cells autoresize initially?

UPDATE: As of Xcode 7 beta 6 this is no longer an issue

回答1:

I ran into the same issue and found out that the accessory cell.accessoryType messes with this automatic resizing when it is not None, so it seems like a bug in Xcode at the moment.

But as @Blankarsch mentioned, calling reloadSections(..) helps to fix this issue if you need to have an accessory.

回答2:

Just call "reloadSections" after your Table is loaded:

self.tableView.reloadSections(NSIndexSet(indexesInRange: NSMakeRange(0, self.tableView.numberOfSections())), withRowAnimation: .None)

Or in Swift 3:

let range = Range(uncheckedBounds: (lower: 0, upper: self.tableView.numberOfSections))
self.tableView.reloadSections(IndexSet(integersIn: range), with: .none)

回答3:

I think the answers over here have fewer side effects. Specifically adding cell.layoutIfNeeded() in tableView:cellForRowAtIndexPath:

I'm also doing what @nosov suggests as is good practice, but haven't tested if they need to be done in tandem.

回答4:

just override estimatedHeightForRowAtIndexPath like this

(CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return UITableViewAutomaticDimension;
}

and check your autoLayout constraints in CustomTableViewCell view.

回答5:

Just make sure that your labels don't have an explicit content size set at Interface Builder. They must be Automatic like the screenshot below for the Automatic Row height to work properly without the need to reload any sections up front.

回答6:

If you set your constraints based on the cell itself (instead of cell content view), the table is not able to get the proper size. So, to fix this issue, your constraints must be set to the content view.

However, this is problem when your cells supports both configuration with/without accessory view. In that case, the content view gets resized according to the accessory view, and the result may not the the expected by the user. So, in this case, a solution is setting 2 constraints, one to the cell and a second one with lower priority to the cell content view.

回答7:

func tableView(_ tableView: UITableView, 
  cellForRowAt indexPath: IndexPath) -> UITableViewCell


- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath;

In the function set the cell with the preferred content, in order for UITableViewAutomaticDimension to work flawlessly.

The problem is caused because the cell content is loaded in some other delegate function, so you can see that cells automatically resize to the required size.

回答8:

Make sure to init your cell in tableView:cellForRowAt:. I've run into this issue even with Xcode 8 when I was setting cell content in tableView:willDisplay:forRowAt:

回答9:

For me I only have this problem when using willDisplay cell to set the text of my labels

If I set the text of my labels in cellForRowAt index path, everything is fine

回答10:

For me what solved it was the combination of @[David Hernandez] answer.

Removed the selection from above, and in Cell's layoutSubviews I set the preferredMaxLayoutWidth as this (change 30 to your desired left right spacing)

-(void) layoutSubviews {
    [super layoutSubviews];
    self.textDescriptionLabel.preferredMaxLayoutWidth = self.frame.size.width - 30;
}

回答11:

Xcode 9.3, Swift 4.1 adding

 func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

in addition to

func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

worked for me.

来源：https://stackoverflow.com/questions/27842764/uitableviewautomaticdimension-not-working-until-scroll

标签

ios

uitableview

swift

uikit