UITableView 单元的动态高度问题(Swift)

可变长度的文本数据被注入到表格视图单元格标签中。为了使每个单元格的高度大小适当，我在 viewDidLoad()中实现了:

self.tableView.estimatedRowHeight = 88.0
self.tableView.rowHeight = UITableViewAutomaticDimension

这将估计高度为88.0像素，如果高度较大，则应自动调整高度的大小。对于滚动到 还没有的单元格(当滚动到单元格 到时调用 UITableViewAutomaticDimention) ，它工作得非常完美，但对于最初在加载数据表时在屏幕上呈现的单元格则不然。

我尝试过重新加载数据(正如许多其他资源所建议的那样) :

self.tableView.reloadData()

in both viewDidAppear() and viewWillAppear() and it did not help. I am lost.. does anyone know how to render the dynamic height for the cells loaded initially on screen?

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Try This:

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}

EDIT

func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}

Swift 4

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

Swift 4.2

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

Define above Both Methods.
It solves the problem.

PS: Top and bottom constraints is required for this to work.

Here is example

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I had also got this issue initially, I had resolved my issue from this code try avoiding the use of self.tableView.reloadData() instead of this code for dynamic height

[self.tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationFade];
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This strange bug was solved through Interface Builder parameters as the other answers did not resolve the issue.

All I did was make the default label size larger than the content potentially could be and have it reflected in the estimatedRowHeight height too. Previously, I set the default row height in Interface Builder to 88px and reflected it like so in my controller viewDidLoad():

self.tableView.rowHeight = UITableViewAutomaticDimension
self.tableView.estimatedRowHeight = 88.0

But that didn't work. So I realized that content wouldn't ever become larger than maybe 100px, so I set the default cell height to 108px (larger than the potential content) and reflected it like so in the controller viewDidLoad():

self.tableView.rowHeight = UITableViewAutomaticDimension
self.tableView.estimatedRowHeight = 108.0

This actually allowed the code to shrink down the initial labels to the correct size. In other words, it never expanded out to a larger size, but could always shrink down... Also, no additional self.tableView.reloadData() was needed in viewWillAppear().

I know this does not cover highly variable content sizes, but this worked in my situation where the content had a maximum possible character count.

Not sure if this is a bug in Swift or Interface Builder but it works like a charm. Give it a try!

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I was just inspired by your solution and tried another way.

Please try to add tableView.reloadData() to viewDidAppear().

This works for me.

I think the things behind scrolling is "the same" as reloadData. When you scroll the screen, it's like calling reloadData() when viewDidAppear .

If this works, plz reply this answer so I could be sure of this solution.

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Try

override func viewWillAppear(animated: Bool) {
self.tableView.layoutSubviews()
}

I had the same problem and it works for me.

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Use this:

tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 300

and don't use: heightForRowAtIndexPath delegate function

Also, in the storyboard don't set the height of the label that contains a large amount of data. Give it top, bottom, leading, trailing constraints.

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SWIFT 3

tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 160

AND!!! In storyBoard: You HAVE TO set TOP & BOTTOM constraints for your Label. Nothing else.

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For Swift 3 you can use the following:

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


func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
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Set proper constraint and update delegate methods as:

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

This will resolve dynamic cell height issue. IF not you need to check constraints.

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Dynamic sizing cell of UITableView required 2 things

  1. Setting the the right constraint of your view inside the table view cell (mostly it includes giving your view proper top , bottom and traling constraints)

  2. Calling these properties of TableView in viewDidLoad()

     tableView.rowHeight = UITableViewAutomaticDimension


tableView.estimatedRowHeight = 140

This is a wonderfull tutorial on self-sizing (dynamic table view cells) written in swift 3 .

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To make autoresizing of UITableViewCell to work make sure you are doing these changes :

  • In Storyboard your UITableView should only contain Dynamic Prototype Cells (It shouldn't use static cells) otherwise autoresizing won't work.
  • In Storyboard your UITableViewCell's UILabel has configured for all 4 constraints that is top, bottom, leading and trailing constraints.
  • In Storyboard your UITableViewCell's UILabel's number of lines should be 0

  • In your UIViewController's viewDidLoad function set below UITableView Properties :

    self.tableView.estimatedRowHeight = <minimum cell height>
self.tableView.rowHeight = UITableViewAutomaticDimension
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You should just set all constraints for TOP, BOTTOM and HEIGHT for each object on cell view/views and remove exists middle Y position if have. Because where you didn't this, puts artifacts on another views.

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Set automatic dimension for row height & estimated row height and ensure following steps:

@IBOutlet weak var table: UITableView!


override func viewDidLoad() {
super.viewDidLoad()


// Set automatic dimensions for row height
// Swift 4.2 onwards
table.rowHeight = UITableView.automaticDimension
table.estimatedRowHeight = UITableView.automaticDimension




// Swift 4.1 and below
table.rowHeight = UITableViewAutomaticDimension
table.estimatedRowHeight = UITableViewAutomaticDimension


}






// UITableViewAutomaticDimension calculates height of label contents/text
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
// Swift 4.2 onwards
return UITableView.automaticDimension


// Swift 4.1 and below
return UITableViewAutomaticDimension
}

For Example: if you have a label in your UITableviewCell then,

  • Set number of lines = 0 (& line break mode = truncate tail)
  • Set all constraints (top, bottom, right left) with respect to its superview/ cell container.
  • Optional: Set minimum height for label, if you want minimum vertical area covered by label, even if there is no data.

Here is sample label with dynamic height constraints.

enter image description here

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For objective c this is one of my nice solution. it's worked for me.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
cell.textLabel.text = [_nameArray objectAtIndex:indexPath.row];
cell.textLabel.numberOfLines = 0;
cell.textLabel.lineBreakMode = NSLineBreakByWordWrapping;
}


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

We need to apply these 2 changes.

1)cell.textLabel.numberOfLines = 0;
cell.textLabel.lineBreakMode = NSLineBreakByWordWrapping;


2)return UITableViewAutomaticDimension;
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For Swift i checked this answer in iOS 9.0 and iOS 11 also (Xcode 9.3)

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}


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

Here you need to add top, bottom, right and left constraints

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In addition to what others have said,

SET YOUR LABEL'S CONSTRAINTS RELATIVE TO THE SUPERVIEW!

So instead of placing your label's constraints relative to other things around it, constrain it to the table view cell's content view.

Then, make sure your label's height is set to more than or equal 0, and the number of lines is set to 0.

Then in ViewDidLoad add:

tableView.estimatedRowHeight = 695


tableView.rowHeight = UITableViewAutomaticDimension
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self.Itemtableview.estimatedRowHeight = 0;
self.Itemtableview.estimatedSectionHeaderHeight = 0;
self.Itemtableview.estimatedSectionFooterHeight = 0;




[ self.Itemtableview reloadData];
self.Itemtableview.frame = CGRectMake( self.Itemtableview.frame.origin.x,  self.Itemtableview.frame.origin.y,  self.Itemtableview.frame.size.width,self.Itemtableview.contentSize.height + self.Itemtableview.contentInset.bottom + self.Itemtableview.contentInset.top);
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For Swift 4.2

@IBOutlet weak var tableVw: UITableView!


override func viewDidLoad() {
super.viewDidLoad()


// Set self as tableView delegate
tableVw.delegate = self


tableVw.rowHeight = UITableView.automaticDimension
tableVw.estimatedRowHeight = UITableView.automaticDimension
}


// UITableViewDelegate Method
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {


return UITableView.automaticDimension
}

Happy Coding :)

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Unfortunately, I am not sure what I was missing. The above methods don't work for me to get the xib cell's height or let the layoutifneeded()or UITableView.automaticDimension to do the height calculation. I've been searching and trying for 3 to 4 nights but could not find an answer. Some answers here or on another post did give me hints for the workaround though. It's a stupid method but it works. Just add all your cells into an Array. And then set the outlet of each of your height constraint in the xib storyboard. Finally, add them up in the heightForRowAt method. It's just straight forward if you are not familiar with the those APIs.

Swift 4.2

CustomCell.Swift

@IBOutlet weak var textViewOneHeight: NSLayoutConstraint!
@IBOutlet weak var textViewTwoHeight: NSLayoutConstraint!
@IBOutlet weak var textViewThreeHeight: NSLayoutConstraint!


@IBOutlet weak var textViewFourHeight: NSLayoutConstraint!
@IBOutlet weak var textViewFiveHeight: NSLayoutConstraint!

MyTableViewVC.Swift

.
.
var myCustomCells:[CustomCell] = []
.
.
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = Bundle.main.loadNibNamed("CustomCell", owner: self, options: nil)?.first as! CustomCell


.
.
myCustomCells.append(cell)
return cell


}




override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {


let totalHeight = myCustomCells[indexPath.row].textViewOneHeight.constant + myCustomCells[indexPath.row].textViewTwoHeight.constant +  myCustomCells[indexPath.row].textViewThreeHeight.constant + myCustomCells[indexPath.row].textViewFourHeight.constant + myCustomCells[indexPath.row].textViewFiveHeight.constant


return totalHeight + 40 //some magic number




}
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I use these

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


return 100
}
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In my case - In storyboard i had a two labels as in image below, both labels was having desired width values been set before i made it equal. once you unselect, it will change to automatic, and as usual having below things should work like charm.

1.rowHeight = UITableView.automaticDimension, and
2.estimatedRowHeight = 100(In my case).
3.make sure label number of lines is zero.

enter image description here

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When using a static UITableView, I set all the values in the UILabels and then call tableView.reloadData().

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This is simple when doing 2 things:

  1. setting the automatic height
tableView.rowHeight = UITableView.automaticDimension
  1. creating all TableViewCells with FULL constraints from top to bottom. The last element MUST define some bottom spacing to end the cell.

So the layout engine can compute the cell heigth and apply the value correctly.

小开 
self.tableView.rowHeight = UITableViewAutomaticDimension
self.tableView.estimatedRowHeight = 88.0

And don't forget to add botton constraints for label

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Swift 5 Enjoy

tablev.rowHeight = 100
tablev.estimatedRowHeight = UITableView.automaticDimension




func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = self.tablev.dequeueReusableCell(withIdentifier: "ConferenceRoomsCell") as! ConferenceRoomsCell
cell.lblRoomName.numberOfLines = 0
cell.lblRoomName.lineBreakMode = .byWordWrapping
cell.lblRoomName.text = arrNameOfRooms[indexPath.row]
cell.lblRoomName.sizeToFit()
return cell
}
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What worked for me was creating a height constraint on my custom cell that I set at runtime (I've got an expand/collapse button in each cell).

Then in heightForRowAt in the parent, I had to do a combination of suggested answers:

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if let cell = tableView.cellForRow(at: indexPath) as? GroupTableViewCell {
return cell.heightConstraint.constant
}
return UITableView.automaticDimension
}


func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return 88.0
}

I use the already calculated height constraint constant where it's available and UITableView.automaticDimension otherwise. This was the only way to get the correct height and maintain the correct cell state when the cell gets recycled.

I hear it's considered bad practice to reference the cell itself inside heightForRowAt, but I don't see another way of doing it with custom cell objects with dynamic heights whilst keeping all constraints satisfied.


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