[英]Swift Unable to simultaneously satisfy constraints error in prepareForSegue?
我嘗試在控制器之間傳遞數據
第一控制器:
class CreateStatmentFieldsController: UITableViewController, DetailsDelegate {
@IBOutlet weak var violationLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// 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()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func violationLabelDelegateMethodWithString(string: String) {
violationLabel.text = string
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
if (segue.identifier == "violationSegue") {
let controller = segue.destinationViewController as CreateStatmentViolationController
controller.delegate = self
}
}
第二控制器:
protocol DetailsDelegate {
func violationLabelDelegateMethodWithString(string: String)
}
class CreateStatmentViolationController: UITableViewController {
var delegate: DetailsDelegate!
@IBOutlet weak var backButton: UIBarButtonItem!
let violations = ["Парковка вторым рядом", "Парковка под знаком \"остановка запрещена\"", "Парковка на тротуаре", "Парковка на пешеходном переходе", "Парковка на месте для инвалидов"]
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func donePressed(b:UIBarButtonItem) {
self.dismissViewControllerAnimated(true, completion: {})
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
tableView.deselectRowAtIndexPath(indexPath, animated: true)
let row = indexPath.row
delegate.violationLabelDelegateMethodWithString("sa")//violations[row]
self.dismissViewControllerAnimated(true, completion: {})
}
// MARK: - Table view data source
//
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Potentially incomplete method implementation.
// Return the number of sections.
return 1
}
//
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete method implementation.
// Return the number of rows in the section.
return violations.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("vilolationCell", forIndexPath: indexPath) as UITableViewCell
let row = indexPath.row
cell.textLabel?.text = violations[row]
// Configure the cell...
return cell
}
但是然后我打開secont控制器我有錯誤:
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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7fdf9a455e70 H:[UIView:0x7fdf9a49ed70(400)]>",
"<NSLayoutConstraint:0x7fdf9a490c80 H:|-(0)-[UIView:0x7fdf9a49ed70] (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a490e00 UIScrollView:0x7fdf9a4958d0.centerX == UIView:0x7fdf9a49ed70.centerX>",
"<NSLayoutConstraint:0x7fdf9a490730 H:[UIScrollView:0x7fdf9a4958d0]-(0)-| (Names: '|':UIView:0x7fdf9a463bb0 )>",
"<NSLayoutConstraint:0x7fdf9a491230 H:|-(0)-[UIScrollView:0x7fdf9a4958d0] (Names: '|':UIView:0x7fdf9a463bb0 )>",
"<NSLayoutConstraint:0x7fdf9a4ae900 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7fdf9a463bb0(375)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7fdf9a455e70 H:[UIView:0x7fdf9a49ed70(400)]>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2015-04-07 01:45:52.768 pin[8690:51798] 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. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7fdf9a49ef70 H:[UIView:0x7fdf9a5a7250(390)]>",
"<NSLayoutConstraint:0x7fdf9a495c00 H:[UIView:0x7fdf9a49ed70]-(0)-| (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a490c80 H:|-(0)-[UIView:0x7fdf9a49ed70] (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a490e00 UIScrollView:0x7fdf9a4958d0.centerX == UIView:0x7fdf9a49ed70.centerX>",
"<NSLayoutConstraint:0x7fdf9a493b00 H:|-(5)-[UIView:0x7fdf9a5a7250] (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a480580 H:[UIView:0x7fdf9a5a7250]-(5)-| (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a490730 H:[UIScrollView:0x7fdf9a4958d0]-(0)-| (Names: '|':UIView:0x7fdf9a463bb0 )>",
"<NSLayoutConstraint:0x7fdf9a491230 H:|-(0)-[UIScrollView:0x7fdf9a4958d0] (Names: '|':UIView:0x7fdf9a463bb0 )>",
"<NSLayoutConstraint:0x7fdf9a4ae900 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7fdf9a463bb0(375)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7fdf9a49ef70 H:[UIView:0x7fdf9a5a7250(390)]>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2015-04-07 01:45:52.774 pin[8690:51798] Warning once only: Detected a case where constraints ambiguously suggest a height of zero for a tableview cell's content view. We're considering the collapse unintentional and using standard height instead.
如果我刪除“ prepareForSegue”功能,則所有工作正常,第二個視圖可以完美打開和關閉,但是我需要將數據發送到filrst控制器。
除非過於簡化,否則錯誤似乎很簡單。
因此,這是調試器的罪魁禍首–
"<NSLayoutConstraint:0x7fdf9a455e70 H:[UIView:0x7fdf9a49ed70(400)]>",
"<NSLayoutConstraint:0x7fdf9a490c80 H:|-(0)-[UIView:0x7fdf9a49ed70] (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a495c00 H:[UIView:0x7fdf9a49ed70]-(0)-| (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a490c80 H:|-(0)-[UIView:0x7fdf9a49ed70] (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
在兩個調試器打印輸出中,都會出現UIView:0x7fdf9a49ed70。 可能要花一些時間,但似乎此視圖的高度已明確設置為400。 然后將其兩次約束到其超級視圖的頂部,一次約束到其超級視圖的底部。
在該打印輸出下,對這些感到不安。
"<NSLayoutConstraint:0x7fdf9a49ef70 H:[UIView:0x7fdf9a5a7250(390)]>",
"<NSLayoutConstraint:0x7fdf9a493b00 H:|-(5)-[UIView:0x7fdf9a5a7250] (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
"<NSLayoutConstraint:0x7fdf9a480580 H:[UIView:0x7fdf9a5a7250]-(5)-| (Names: '|':UIScrollView:0x7fdf9a4958d0 )>",
因此,視圖再次被限制在其superView的頂部和底部。 該視圖的顯式高度也設置為390點。
看起來,在segue期間的某個時候甚至在segue之后,superView的高度分別不等於390或400,因此無法滿足約束。 如果我是你,我要么沒有明確設定的若干意見的高度,只有約束頂部和底部或設置高度和約束他們的頂部或底部。 這三個約束不是必需的,在這種情況下,不可能同時實現。
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