How to update height Constraints by SnapKit and update cell height?
I have a TableViewCell and two button to switch different constrain.
I want to update it's height constrain and cell height.
like following pic1
when I click buttonB, the view will change like pic2
Then I click buttonA, the view will back to pic1
I try to modify constrains, but I fail to update height.
Have any idea or answer to me?
Thanks
pic1
pic2
Here is code:
class CellContainView: UIView {
let buttonA: UIButton = { () -> UIButton in
let ui = UIButton()
ui.titleLabel?.numberOfLines = 0
ui.setTitle("Click\nA", for: .normal)
ui.backgroundColor = UIColor.blue
return ui
}()
let buttonB: UIButton = { () -> UIButton in
let ui = UIButton()
ui.titleLabel?.numberOfLines = 0
ui.setTitle("Click\nB", for: .normal)
ui.backgroundColor = UIColor.gray
return ui
}()
let buttonC: UIButton = { () -> UIButton in
let ui = UIButton()
ui.titleLabel?.numberOfLines = 0
ui.setTitle("Click\nC", for: .normal)
ui.backgroundColor = UIColor.brown
return ui
}()
let labelA: UILabel = { () -> UILabel in
let ui = UILabel()
ui.text = "Test"
return ui
}()
let viewA: UIView = { () -> UIView in
let ui = UIView()
ui.backgroundColor = UIColor.red
return ui
}()
override init(frame: CGRect) {
super.init(frame: frame)
addUI()
addConstrain()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func addUI() {
self.addSubview(buttonA)
self.addSubview(buttonB)
self.addSubview(buttonC)
self.addSubview(labelA)
self.addSubview(viewA)
}
func addConstrain() {
buttonA.snp.makeConstraints { (make) in
make.left.top.equalToSuperview()
make.height.equalTo(60)
}
buttonB.snp.makeConstraints { (make) in
make.left.equalTo(buttonA.snp.right)
make.top.right.equalToSuperview()
make.width.equalTo(buttonA.snp.width)
make.height.equalTo(buttonA.snp.height)
}
buttonC.snp.makeConstraints { (make) in
make.left.equalTo(15)
make.right.equalTo(-15)
make.bottom.equalTo(-15)
make.height.equalTo(50)
}
labelA.snp.makeConstraints { (make) in
make.left.equalTo(15)
make.top.equalTo(buttonA.snp.bottom).offset(15)
make.width.equalTo(195)
make.height.equalTo(50)
}
viewA.snp.makeConstraints { (make) in
make.left.equalTo(labelA.snp.right)
make.top.equalTo(buttonA.snp.bottom).offset(15)
make.right.equalTo(-15)
make.height.equalTo(50)
make.bottom.equalTo(buttonC.snp.top).offset(-10)
}
}
func updateConstrain(sender: UIButton) {
switch sender {
case buttonA:
viewA.snp.updateConstraints { (make) in
make.height.equalTo(50)
}
case buttonB:
viewA.snp.updateConstraints { (make) in
make.height.equalTo(150)
}
default:
break
}
}
}
class TestTableViewCell: UITableViewCell {
let cellContainView: CellContainView = { () -> CellContainView in
let ui = CellContainView()
ui.backgroundColor = UIColor.orange
return ui
}()
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
self.addSubview(cellContainView)
cellContainView.snp.makeConstraints { (make) in
make.left.top.equalTo(15)
make.bottom.right.equalTo(-15)
}
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
let tableView: UITableView = { () -> UITableView in
let ui = UITableView()
return ui
}()
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 44
tableView.register(TestTableViewCell.self, forCellReuseIdentifier: "TestTableViewCell")
tableView.tableFooterView = UIView()
self.view.addSubview(tableView)
tableView.snp.makeConstraints { (make) in
make.top.left.right.bottom.equalToSuperview()
}
}
@objc func buttonAClicked(sender: UIButton) {
let index = IndexPath(row: 0, section: 0)
let cell = tableView.cellForRow(at: index) as! TestTableViewCell
cell.cellContainView.updateConstrain(sender: sender)
tableview.reloadData()
}
@objc func buttonBClicked(sender: UIButton) {
let index = IndexPath(row: 0, section: 0)
let cell = tableView.cellForRow(at: index) as! TestTableViewCell
cell.cellContainView.updateConstrain(sender: sender)
tableview.reloadData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "TestTableViewCell", for: indexPath) as! TestTableViewCell
cell.cellContainView.buttonA.addTarget(self, action: #selector(buttonAClicked), for: .touchUpInside)
cell.cellContainView.buttonB.addTarget(self, action: #selector(buttonBClicked), for: .touchUpInside)
return cell
}
}
Update constrain problem when I click butttonB (Add update viewA heightConstrain & tableview.reloadData()):
TestCellUpdateHeight[29975:5195310] [LayoutConstraints] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want.
Try this:
(1) look at each constraint and try to figure out which you don't expect;
(2) find the code that added the unwanted constraint or constraints and fix it.
(
"<SnapKit.LayoutConstraint:[email protected]#75 UIButton:0x7fa1d0d0d680.height == 60.0>",
"<SnapKit.LayoutConstraint:[email protected]#89 UIButton:0x7fa1d0d10610.height == 50.0>",
"<SnapKit.LayoutConstraint:[email protected]#104 UIView:0x7fa1d0d11130.height == 150.0>",
"<SnapKit.LayoutConstraint:[email protected]#80 UIButton:0x7fa1d0d0f7b0.top == TestCellUpdateHeight.CellContainView:0x7fa1d0d0d470.top>",
"<SnapKit.LayoutConstraint:[email protected]#82 UIButton:0x7fa1d0d0f7b0.height == UIButton:0x7fa1d0d0d680.height>",
"<SnapKit.LayoutConstraint:[email protected]#88 UIButton:0x7fa1d0d10610.bottom == TestCellUpdateHeight.CellContainView:0x7fa1d0d0d470.bottom - 15.0>",
"<SnapKit.LayoutConstraint:[email protected]#102 UIView:0x7fa1d0d11130.top == UIButton:0x7fa1d0d0f7b0.bottom + 15.0>",
"<SnapKit.LayoutConstraint:[email protected]#105 UIView:0x7fa1d0d11130.bottom == UIButton:0x7fa1d0d10610.top - 10.0>",
"<SnapKit.LayoutConstraint:[email protected]#26 TestCellUpdateHeight.CellContainView:0x7fa1d0d0d470.top == TestCellUpdateHeight.TestTableViewCell:0x7fa1d208a000.top + 15.0>",
"<SnapKit.LayoutConstraint:[email protected]#27 TestCellUpdateHeight.CellContainView:0x7fa1d0d0d470.bottom == TestCellUpdateHeight.TestTableViewCell:0x7fa1d208a000.bottom - 15.0>",
"<NSLayoutConstraint:0x6080002819f0 'UIView-Encapsulated-Layout-Height' TestCellUpdateHeight.TestTableViewCell:0x7fa1d208a000'TestTableViewCell'.height == 230 (active)>"
)
Will attempt to recover by breaking constraint
Answer
In general, to update the height constraint of a uiview:UIView you should save it first:
var viewHeightConstraint: Constraint!
uiview.snp.makeConstraints { (make) in
viewHeightConstraint = make.height.equalTo(50).constraint
}
If you simply use updateConstraints function, it will add a new height constraint that causes the issue Unable to simultaneously satisfy constraints. So you have to remove the last one:
viewHeightConstraint.deactivate()
Then make constraint again:
uiview.snp.makeConstraints { (make) in
viewHeightConstraint = make.height.equalTo(100).constraint
}