我正在使用Swift创建一个iOS应用,以帮助我使用UITableView
来跟踪学校的作业。但是,在点击添加按钮时,当它尝试添加新行时,应用程序崩溃。我看过Brian Voong,Sean Allen,Kilo Loco等提供的无数教程,并阅读了Apple的教程和文档,但仍然无法弄清问题所在。我错过了什么?我编码不正确吗?
崩溃时,我收到错误消息:
2019-05-06 23:28:58.200728-0500 AssignmentTracker[18768:1102271] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /Users/joshroot/Library/Developer/CoreSimulator/Devices/45F175C3-2A67-4EB6-9F1D-DE8503AEEDA8/data/Containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
2019-05-06 23:28:58.201136-0500 AssignmentTracker[18768:1102271] [MC] Reading from private effective user settings.
2019-05-06 23:29:18.701240-0500 AssignmentTracker[18768:1102271] *** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKitCore_Sim/UIKit-3698.103.12/UITableView.m:1821
2019-05-06 23:29:18.713115-0500 AssignmentTracker[18768:1102271] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'attempt to insert row 0 into section 0, but there are only 0 rows in section 0 after the update'
*** First throw call stack:
(
0 CoreFoundation 0x00000001116416fb __exceptionPreprocess + 331
1 libobjc.A.dylib 0x000000010f98dac5 objc_exception_throw + 48
2 CoreFoundation 0x0000000111641482 +[NSException raise:format:arguments:] + 98
3 Foundation 0x000000010f3db927 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 194
4 UIKitCore 0x000000011aad86a7 -[UITableView _endCellAnimationsWithContext:] + 8315
5 UIKitCore 0x000000011aaf3e6f -[UITableView endUpdates] + 74
6 AssignmentTracker 0x000000010f0900e1 $s17AssignmentTracker14ViewControllerC9insertRow10assignmentyAA0A0C_tF + 1169
7 AssignmentTracker 0x000000010f08fb6b $s17AssignmentTracker14ViewControllerC15addButtonTappedyyF + 6107
8 AssignmentTracker 0x000000010f08fc34 $s17AssignmentTracker14ViewControllerC15addButtonTappedyyFTo + 36
9 UIKitCore 0x000000011a8de204 -[UIApplication sendAction:to:from:forEvent:] + 83
10 UIKitCore 0x000000011a333c19 -[UIControl sendAction:to:forEvent:] + 67
11 UIKitCore 0x000000011a333f36 -[UIControl _sendActionsForEvents:withEvent:] + 450
12 UIKitCore 0x000000011a332eec -[UIControl touchesEnded:withEvent:] + 583
13 UIKitCore 0x000000011a916eee -[UIWindow _sendTouchesForEvent:] + 2547
14 UIKitCore 0x000000011a9185d2 -[UIWindow sendEvent:] + 4079
15 UIKitCore 0x000000011a8f6d16 -[UIApplication sendEvent:] + 356
16 UIKitCore 0x000000011a9c7293 __dispatchPreprocessedEventFromEventQueue + 3232
17 UIKitCore 0x000000011a9c9bb9 __handleEventQueueInternal + 5911
18 CoreFoundation 0x00000001115a8be1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
19 CoreFoundation 0x00000001115a8463 __CFRunLoopDoSources0 + 243
20 CoreFoundation 0x00000001115a2b1f __CFRunLoopRun + 1231
21 CoreFoundation 0x00000001115a2302 CFRunLoopRunSpecific + 626
22 GraphicsServices 0x0000000115ad82fe GSEventRunModal + 65
23 UIKitCore 0x000000011a8dcba2 UIApplicationMain + 140
24 AssignmentTracker 0x000000010f0920ab main + 75
25 libdyld.dylib 0x0000000112a49541 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
-中的代码 ViewController.swift:
import UIKit;
class ViewController: UIViewController {
var assignments: [Assignment] = [Assignment]();
@IBOutlet weak var assignmentsTable: UITableView!;
@IBOutlet weak var doneButton: DoneButton!;
@IBOutlet weak var assignmentNameField: UITextField!;
@IBOutlet weak var assignmentDateAssignedField: UITextField!;
@IBOutlet weak var assignmentDueDateField: UITextField!;
@IBOutlet weak var assignmentWeightOfAssignmentField: UITextField!;
var textFields: [UITextField] = [];
override func viewDidLoad() {
super.viewDidLoad();
textFields =
[
assignmentNameField,
assignmentDateAssignedField,
assignmentDueDateField,
assignmentWeightOfAssignmentField
];
doneButton.addTarget(self, action: #selector(addButtonTapped), for: .touchUpInside);
Util.setupViewControllerSytles(fields: textFields, viewController: self);
}
@objc func addButtonTapped() {
doneButton.shake();
let isDataValid: Bool = ValidationUtil.isValidData(viewController: self, name: assignmentNameField.text!, dueDate: assignmentDueDateField.text!, dateAssigned: assignmentDateAssignedField.text!, assignmentWeight: assignmentWeightOfAssignmentField.text!);
if (isDataValid) {
insertRow(assignment: Assignment(name: assignmentNameField.text!, dueDate: assignmentDueDateField.text!, assignedDate: assignmentDateAssignedField.text!, assignmentWeight: Double(assignmentWeightOfAssignmentField.text!)!));
}
}
func insertRow(assignment: Assignment) {
assignments.append(assignment);
let indexPath: IndexPath = IndexPath(row: assignments.count - 1, section: 0);
assignmentsTable.beginUpdates();
assignmentsTable.insertRows(at: [indexPath], with: .bottom);
assignmentsTable.endUpdates();
Util.cleanUp(fields: textFields);
}
}
extension ViewController: UITextFieldDelegate {
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
self.view.endEditing(true);
return false;
}
}
extension ViewController: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return assignments.count;
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let assignment = assignments[indexPath.row];
let cell = tableView.dequeueReusableCell(withIdentifier: "AssignmentCell") as! AssignmentCell;
Util.setupAssignmentCell(cell: cell, assignment: assignment);
return cell;
}
}
setupAssignmentCell函数
static func setupAssignmentCell(cell: AssignmentCell, assignment: Assignment) {
cell.assignmentNameLabel.text = "Name: \(assignment.getName())";
cell.assignmentDueDateLabel.text = "Due Date: \(assignment.getDueDate())";
cell.assignmentAssignedDateLabel.text = "Assigned: \(assignment.getAssignedDate())";
cell.assignmentWeightLabel.text = "Weight (%): \(assignment.getAssignmentWeight())";
}
答案 0 :(得分:-1)
问题似乎是由于在调用assignments
函数之前更新beginUpdates
数组引起的。
所以我的建议解决方案是在调用assignments
之后更改beginUpdates
数组,如下所示:
assignmentsTable.beginUpdates();
assignments.append(assignment);
let indexPath: IndexPath = IndexPath(row: assignments.count - 1, section: 0);
assignmentsTable.insertRows(at: [indexPath], with: .bottom);
assignmentsTable.endUpdates();