UITableView tableFooterView shows at the top of the UITableView - wrong

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北海茫月
北海茫月 2021-02-08 15:37

I have created a very simple test case to reproduce this issue.

I am trying to set a footer view programmatically to a tableview. Please note that I am referring to the

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  • 2021-02-08 16:04

    set grouped style for table and set height for header CGFloat.leastNonzeroMagnitude

    tableView.style = .grouped
    
    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        return CGFloat.leastNonzeroMagnitude
    }
    
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  • 2021-02-08 16:05

    Do not set translatesAutoresizingMaskIntoConstraints = false on a UIView being assigned to tableView.tableFooterView.

    In your case, this is footerContainer. I had this same problem. It was mentioned in a comment on the question, but I still spent hours troubleshooting before I noticed I was doing that, so I am putting it here as a possible answer as well.

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  • 2021-02-08 16:10

    Dynamic-sized UITableView Header and Footer views do not always play nice with auto-layout, so you need to give it a little help.

    Here is an example that creates a simple UIView for the footer view and adds an "expanding" UILabel (number of lines set to Zero). The footer view is created with an explicit CGRect for its frame, and the label is pinned to all four sides with auto-layout constraints.

    In viewDidLayoutSubviews(), we tell auto-layout to calculate the frame of the footer view, based on the constraints on its contents, and then we update the frame values (well, specifically the height).

    //
    // this assumes IBOutlet has been set for "theTableView"
    //
    
    - (void)viewDidLoad {
        [super viewDidLoad];
    
        // standard stuff
        [_theTableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"simpleCell"];
        _theTableView.delegate = self;
        _theTableView.dataSource = self;
    
        // instantiate a view for the table footer
        // width doesn't matter (it will be stretched to fit the table by default)
        // set height to a big number to avoid a "will attempt to break constraint" warning
        UIView *footerContainer = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1, 1000)];
    
        // give it a color so we can see it
        footerContainer.backgroundColor=[UIColor greenColor];
    
        // set the footer view
        _theTableView.tableFooterView = footerContainer;
    
    
        // instantiate a label to add to the footer view
        UILabel *aLabel = [UILabel new];
    
        // auto-sizing the height, so set lines to zero
        aLabel.numberOfLines = 0;
    
        // give it a color so we can see it
        aLabel.backgroundColor = [UIColor yellowColor];
    
        // set the text to 8 lines for demonstration purposes
        aLabel.text = @"Line 1\nLine 2\nLine 3\nLine 4\nLine 5\nLine 6\nLine 7\nLine 8";
    
        // standard, for auto-sizing
        aLabel.translatesAutoresizingMaskIntoConstraints = NO;
    
        // add the label to the footer view
        [footerContainer addSubview:aLabel];
    
        // constraint the label to 8-pts from each edge...
        [aLabel.topAnchor constraintEqualToAnchor:footerContainer.topAnchor constant:8.0].active = YES;
        [aLabel.leftAnchor constraintEqualToAnchor:footerContainer.leftAnchor constant:8.0].active = YES;
        [aLabel.rightAnchor constraintEqualToAnchor:footerContainer.rightAnchor constant:-8.0].active = YES;
        [aLabel.bottomAnchor constraintEqualToAnchor:footerContainer.bottomAnchor constant:-8.0].active = YES;
    
    }
    
    - (void)viewDidLayoutSubviews {
        [super viewDidLayoutSubviews];
    
        // get a reference to the table's footer view
        UIView *currentFooterView = [_theTableView tableFooterView];
    
        // if it's a valid reference (the table *does* have a footer view)
        if (currentFooterView) {
    
            // tell auto-layout to calculate the size based on the footer view's content
            CGFloat newHeight = [currentFooterView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
    
            // get the current frame of the footer view
            CGRect currentFrame = currentFooterView.frame;
    
            // we only want to do this when necessary (otherwise we risk infinite recursion)
            // so... if the calculated height is not the same as the current height
            if (newHeight != currentFrame.size.height) {
                // use the new (calculated) height
                currentFrame.size.height = newHeight;
                currentFooterView.frame = currentFrame;
            }
    
        }
    
    }
    

    This can also be helpful when trying to get auto-sizing table view header views to work properly.

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  • 2021-02-08 16:10

    I have tried the same with explicit frame values in swift and I achieved the behaviour as you asked for, Try it with the explicit frame value if you think its fine. And remove the layout constraints if its not needed.

       @IBOutlet weak var tableView: UITableView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
    
        tableView.delegate = self
        tableView.dataSource = self
    
        let footerView = UIView(frame: CGRect.init(x: 0, y: 0, width: tableView.frame.width, height: 50))
        footerView.backgroundColor = UIColor.green
        tableView.tableFooterView = footerView
    }
    
    extension ViewController: UITableViewDelegate, UITableViewDataSource {
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 10
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
        cell?.textLabel?.text = "\(indexPath.row)"
        return cell!
    }
    

    }

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  • 2021-02-08 16:14

    The table view is ignoring the constraints.
    Set the height manually and it'll work:

    tableView.tableFooterView?.frame.size.height = 20
    
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  • 2021-02-08 16:18

    You can use Autolayout and Xibs to create a footer view. But you have to put your custom view to the container view, that you assign to tableFooterView.

    func setupTableFooterView() {
        // Create your footer view from XIB and set constraints (in my case it is historyToolBarView of class HistoryToolBarView)
        let view = Bundle.main.loadNibNamed("HistoryToolBarView", owner: self, options: nil)?.first
        historyToolBarView = view as! HistoryToolBarView
        historyToolBarView.translatesAutoresizingMaskIntoConstraints = false
        historyToolBarView.addConstraints(
            [NSLayoutConstraint.init(item: self.historyToolBarView,
                                     attribute: .height,
                                     relatedBy: .equal,
                                     toItem: nil,
                                     attribute: .notAnAttribute,
                                     multiplier: 1.0,
                                     constant: 60),
             NSLayoutConstraint.init(item: self.historyToolBarView,
                                     attribute: .width,
                                     relatedBy: .equal,
                                     toItem: nil,
                                     attribute: .notAnAttribute,
                                     multiplier: 1.0,
                                     constant: UIScreen.main.bounds.size.width)])
    
        // Create a container of your footer view called footerView and set it as a tableFooterView
        let footerView = UIView(frame: CGRect.init(x: 0, y: 0, width: tableView.frame.width, height: 60))
        footerView.backgroundColor = UIColor.green
        tableView.tableFooterView = footerView
    
        // Add your footer view to the container
        footerView.addSubview(historyToolBarView)
    }
    
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