我创建了一个程序，其中选择器在单击我的文本字段时显示，并且当我单击＆＃34;完成＆＃34;时我试图忽略它。或者＆＃34;取消＆＃34;我的工具栏上的按钮。
我不知道哪里出错了。虽然它说
＆＃34; 2017-09-28 20：45：27.877897-0600 project1 [51296：5112470] [LayoutConstraints]无法同时满足约束条件。＆＃34;
我所有的约束都工作正常..
这是我的代码：
@IBOutlet weak var textField1: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
let picker: UIPickerView
picker = UIPickerView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: 300))
picker.backgroundColor = .white
picker.showsSelectionIndicator = true
picker.delegate = self
picker.dataSource = self
let toolBar = UIToolbar(frame: CGRect(x: 0, y: 0, width: view.frame.size.width, height: 40))
toolBar.barStyle = UIBarStyle.default
toolBar.isTranslucent = true
toolBar.tintColor = .black
let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.plain, target: self, action:
Selector(("donePicker")))
let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
let cancelButton = UIBarButtonItem(title: "Cancel", style: UIBarButtonItemStyle.plain, target: self, action: Selector(("donePicker")))
)
toolBar.setItems([cancelButton, spaceButton, doneButton], animated: true)
toolBar.isUserInteractionEnabled = true
let bgView = UIView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: 250 + toolBar.frame.size.height))
print(picker.frame.size.height, toolBar.frame.size.height, bgView.frame.size.height)
bgView.addSubview(picker)
bgView.addSubview(toolBar)
textField1.inputView = bgView
}
func donePicker() {
textField1.resignFirstResponder()
}
这是它给我的错误：
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.
2017-09-28 20:45:29.253610-0600 project1[51296:5112470] [MC] Lazy loading NSBundle MobileCoreServices.framework
2017-09-28 20:45:29.255001-0600 project1[51296:5112470] [MC] Loaded MobileCoreServices.framework
2017-09-28 20:45:29.274235-0600 project1[51296:5112470] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /Users/Andrew/Library/Developer/CoreSimulator/Devices/EE44EDE5-BDF6-4A15-A44B-387E14685DAA/data/Containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
300.0 44.0 294.0
2017-09-28 20:45:30.401748-0600 project1[51296:5112470] [MC] Reading from private effective user settings.
2017-09-28 20:45:31.827410-0600 project1[51296:5112470] -[project1.CalculateViewController donePicker]: unrecognized selector sent to instance 0x7faac1d0fab0
2017-09-28 20:45:31.835746-0600 project1[51296:5112470] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[project1.CalculateViewController donePicker]: unrecognized selector sent to instance 0x7faac1d0fab0'
*** First throw call stack:
(
0 CoreFoundation 0x000000010c8a11cb __exceptionPreprocess + 171
1 libobjc.A.dylib 0x000000010a93cf41 objc_exception_throw + 48
2 CoreFoundation 0x000000010c921914 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
3 UIKit 0x000000010d4660bd -[UIResponder doesNotRecognizeSelector:] + 295
4 CoreFoundation 0x000000010c824178 ___forwarding___ + 1432
5 CoreFoundation 0x000000010c823b58 _CF_forwarding_prep_0 + 120
6 UIKit 0x000000010d23f9bd -[UIApplication sendAction:to:from:forEvent:] + 83
7 UIKit 0x000000010dc3353f __45-[_UIButtonBarTargetAction _invoke:forEvent:]_block_invoke + 154
8 UIKit 0x000000010dc33470 -[_UIButtonBarTargetAction _invoke:forEvent:] + 181
9 UIKit 0x000000010d23f9bd -[UIApplication sendAction:to:from:forEvent:] + 83
10 UIKit 0x000000010d3b6183 -[UIControl sendAction:to:forEvent:] + 67
11 UIKit 0x000000010d3b64a0 -[UIControl _sendActionsForEvents:withEvent:] + 450
12 UIKit 0x000000010d3b53cd -[UIControl touchesEnded:withEvent:] + 618
13 UIKit 0x000000010d2b3d4f -[UIWindow _sendTouchesForEvent:] + 2807
14 UIKit 0x000000010d2b5472 -[UIWindow sendEvent:] + 4124
15 UIKit 0x000000010d25a802 -[UIApplication sendEvent:] + 352
16 UIKit 0x000000010db8ca50 __dispatchPreprocessedEventFromEventQueue + 2809
17 UIKit 0x000000010db8f5b7 __handleEventQueueInternal + 5957
18 CoreFoundation 0x000000010c8442b1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
19 CoreFoundation 0x000000010c8e3d31 __CFRunLoopDoSource0 + 81
20 CoreFoundation 0x000000010c828c19 __CFRunLoopDoSources0 + 185
21 CoreFoundation 0x000000010c8281ff __CFRunLoopRun + 1279
22 CoreFoundation 0x000000010c827a89 CFRunLoopRunSpecific + 409
23 GraphicsServices 0x00000001122ee9c6 GSEventRunModal + 62
24 UIKit 0x000000010d23dd30 UIApplicationMain + 159
25 UofA Engineering Master 0x0000000109ffa307 main + 55
26 libdyld.dylib 0x000000010fbc5d81 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
答案 0 :(得分：0)
我尝试了另一种方法在PickerView中展示toolbar和textField。
如果在您的方案中有所帮助，请尝试此操作：
let toolBar = UIToolbar()
toolBar.barStyle = UIBarStyle.default
toolBar.isTranslucent = true
toolBar.tintColor = UIColor(red: 76/255, green: 217/255, blue: 100/255, alpha: 1)
toolBar.sizeToFit()
let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.plain, target: self, action: #selector(CalculateViewController.donePicker))
let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
let cancelButton = UIBarButtonItem(title: "Cancel", style: UIBarButtonItemStyle.plain, target: self, action: #selector(CalculateViewController.cancelPicker))
toolBar.setItems([cancelButton, spaceButton, doneButton], animated: false)
toolBar.isUserInteractionEnabled = true
textField1.inputView = pickerView
textField1.inputAccessoryView = toolBar
答案 1 :(得分：0)
您可以看到错误消息：
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[project1.CalculateViewController donePicker]: unrecognized selector sent to instance 0x7faac1d0fab0'
对于Swift，我们没有像那样定义selector（它是Objective C方式）。你应该这样使用：
let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.plain, target: self, action:
#selector(donePicker))
答案 2 :(得分：0)
由于错误是无法识别的选择器发送到实例，您可以让选择器成为属性。使用let picker: UIPickerView
viewdidload方法中的var picker: UIPickerView?