我创建了一个控制器，它将为管理员提供将新学生添加到数据库的选项。我试图将UIPicker添加到使用不同自定义单元格的表视图中的文本字段中。
选择该字段时，会弹出UIPicker，它还会返回阵列中的所有数据。问题是从UIPicker中选择了某些内容后，我的文本字段没有更新。但是，只需简单地打印到控制台，即可确认选择是否有效。
如何将我的选择正确发送到链接到UIPicker的文本字段？
class AddStudentInfoController: UITableViewController, UITextFieldDelegate, UIPickerViewDelegate, UIPickerViewDataSource {
@IBOutlet var addStudentGradeTextField: UITextField!
var pickerGrade = UIPickerView()
var allCellsText = [String]()
let firstNameCell = "firstNameCell"
let lastNameCell = "lastNameCell"
let gradeCell = "gradeCell"
var array = ["First Name", "Last Name", "Grade"]
var grade = ["--", "One", "Two", "Three"]
override func viewDidLoad() {
super.viewDidLoad()
pickerGrade.delegate = self
pickerGrade.dataSource = self
pickerGrade.backgroundColor = UIColor.white
self.tableView.tableFooterView = UIView(frame: CGRect.zero)
self.tableView.rowHeight = 60
tableView.register(AddStudentFirstNameCell.self, forCellReuseIdentifier: firstNameCell)
tableView.register(AddStudentLastNameCell.self, forCellReuseIdentifier: lastNameCell)
tableView.register(AddStudentGradeCell.self, forCellReuseIdentifier: gradeCell)
}
// Load tableview
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return array.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == 0 {
let cell = tableView.dequeueReusableCell(withIdentifier: firstNameCell, for: indexPath) as! AddStudentFirstNameCell
cell.textLabel!.text = self.array[indexPath.row]
cell.selectionStyle = UITableViewCellSelectionStyle.none
return cell
}
else if indexPath.row == 1 {
let cell = tableView.dequeueReusableCell(withIdentifier: lastNameCell, for: indexPath) as! AddStudentLastNameCell
cell.textLabel!.text = self.array[indexPath.row]
cell.selectionStyle = UITableViewCellSelectionStyle.none
return cell
}
else {
let cell = tableView.dequeueReusableCell(withIdentifier: gradeCell, for: indexPath) as! AddStudentGradeCell
cell.textLabel!.text = self.array[indexPath.row]
cell.selectionStyle = UITableViewCellSelectionStyle.none
cell.addStudentGradeTextField?.inputView = pickerGrade
return cell
}
}
// Picker view
func textFieldDidBeginEditing(_ textField: UITextField) {
pickerGrade.reloadAllComponents()
pickerGrade.isHidden = false
}
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{
return grade.count
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
addStudentGradeTextField?.text = grade[row]
self.view.endEditing(true)
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return grade[row]
}
// End editing
func textFieldDidEndEditing(_ textField: UITextField) {
allCellsText.append(textField.text!)
}
}
我所有用于表视图的自定义单元格。
// #
// Custom cells for AddStudent.swift
// #
class AddStudentFirstNameCell: UITableViewCell {
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let addStudentTextField: UITextField = {
let addStudentTextField = UITextField()
addStudentTextField.placeholder = "First Name"
addStudentTextField.textColor = .red
addStudentTextField.translatesAutoresizingMaskIntoConstraints = false
addStudentTextField.rightViewMode = UITextFieldViewMode.always
addStudentTextField.autocorrectionType = .no
return addStudentTextField
}()
func setupViews() {
addSubview(addStudentTextField)
addStudentTextField.rightAnchor.constraint(equalTo: self.rightAnchor, constant: 10).isActive = true
addStudentTextField.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
addStudentTextField.widthAnchor.constraint(equalToConstant: 150).isActive = true
addStudentTextField.heightAnchor.constraint(equalToConstant: 48).isActive = true
}
}
class AddStudentLastNameCell: UITableViewCell {
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let addStudentTextField: UITextField = {
let addStudentTextField = UITextField()
addStudentTextField.placeholder = "Last Name"
addStudentTextField.textColor = .red
addStudentTextField.translatesAutoresizingMaskIntoConstraints = false
addStudentTextField.rightViewMode = UITextFieldViewMode.always
addStudentTextField.autocorrectionType = .no
return addStudentTextField
}()
func setupViews() {
addSubview(addStudentTextField)
addStudentTextField.rightAnchor.constraint(equalTo: self.rightAnchor, constant: 10).isActive = true
addStudentTextField.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
addStudentTextField.widthAnchor.constraint(equalToConstant: 150).isActive = true
addStudentTextField.heightAnchor.constraint(equalToConstant: 48).isActive = true
}
}
class AddStudentGradeCell: UITableViewCell {
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)
setupViews()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let addStudentGradeTextField: UITextField! = {
let addStudentGradeTextField = UITextField()
addStudentGradeTextField.placeholder = "--"
addStudentGradeTextField.textColor = .red
addStudentGradeTextField.translatesAutoresizingMaskIntoConstraints = false
addStudentGradeTextField.rightViewMode = UITextFieldViewMode.always
addStudentGradeTextField.autocorrectionType = .no
return addStudentGradeTextField
}()
func setupViews() {
addSubview(addStudentGradeTextField)
addStudentGradeTextField.rightAnchor.constraint(equalTo: self.rightAnchor, constant: 10).isActive = true
addStudentGradeTextField.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
addStudentGradeTextField.widthAnchor.constraint(equalToConstant: 150).isActive = true
addStudentGradeTextField.heightAnchor.constraint(equalToConstant: 48).isActive = true
}
}
崩溃日志
Starry`@objc AddStudentGradeCell.init(style : UITableViewCellStyle, reuseIdentifier : String?) -> AddStudentGradeCell:
0x10a402980 <+0>: pushq %rbp
0x10a402981 <+1>: movq %rsp, %rbp
0x10a402984 <+4>: subq $0x70, %rsp
0x10a402988 <+8>: movq %rdi, -0x28(%rbp)
0x10a40298c <+12>: movq %rcx, %rdi
0x10a40298f <+15>: movq %rdx, -0x30(%rbp)
0x10a402993 <+19>: movq %rsi, -0x38(%rbp)
0x10a402997 <+23>: movq %rcx, -0x40(%rbp)
0x10a40299b <+27>: callq 0x10a46732a ; symbol stub for: objc_retain
0x10a4029a0 <+32>: movq -0x40(%rbp), %rcx
0x10a4029a4 <+36>: cmpq $0x0, %rcx
0x10a4029a8 <+40>: sete %r8b
0x10a4029ac <+44>: xorb $-0x1, %r8b
0x10a4029b0 <+48>: testb $0x1, %r8b
0x10a4029b4 <+52>: movq %rax, -0x48(%rbp)
0x10a4029b8 <+56>: jne 0x10a4029bc ; <+60> at AddStudent.swift
0x10a4029ba <+58>: jmp 0x10a4029dc ; <+92> at AddStudent.swift
0x10a4029bc <+60>: movq -0x40(%rbp), %rdi
0x10a4029c0 <+64>: callq 0x10a46747a ; symbol stub for: static (extension in Foundation):Swift.String._unconditionallyBridgeFromObjectiveC (Swift.Optional<__ObjC.NSString>) -> Swift.String
0x10a4029c5 <+69>: xorl %esi, %esi
0x10a4029c7 <+71>: movb %sil, %r8b
0x10a4029ca <+74>: movq %rcx, -0x50(%rbp)
0x10a4029ce <+78>: movq %rax, -0x58(%rbp)
0x10a4029d2 <+82>: movq %rdx, -0x60(%rbp)
0x10a4029d6 <+86>: movb %r8b, -0x61(%rbp)
0x10a4029da <+90>: jmp 0x10a4029f9 ; <+121> at AddStudent.swift
0x10a4029dc <+92>: xorl %eax, %eax
0x10a4029de <+94>: movl %eax, %ecx
0x10a4029e0 <+96>: movb $0x1, %dl
0x10a4029e2 <+98>: movq %rcx, %rsi
0x10a4029e5 <+101>: movq %rcx, %rdi
0x10a4029e8 <+104>: movq %rdi, -0x60(%rbp)
0x10a4029ec <+108>: movq %rcx, -0x50(%rbp)
0x10a4029f0 <+112>: movq %rsi, -0x58(%rbp)
0x10a4029f4 <+116>: movb %dl, -0x61(%rbp)
0x10a4029f7 <+119>: jmp 0x10a4029f9 ; <+121> at AddStudent.swift
0x10a4029f9 <+121>: movb -0x61(%rbp), %al
0x10a4029fc <+124>: movq -0x50(%rbp), %rcx
0x10a402a00 <+128>: movq -0x60(%rbp), %rdx
0x10a402a04 <+132>: movq -0x58(%rbp), %rsi
0x10a402a08 <+136>: leaq -0x20(%rbp), %rdi
0x10a402a0c <+140>: movq %rsi, -0x20(%rbp)
0x10a402a10 <+144>: movq %rdx, -0x18(%rbp)
0x10a402a14 <+148>: movq %rcx, -0x10(%rbp)
0x10a402a18 <+152>: andb $0x1, %al
0x10a402a1a <+154>: movb %al, -0x8(%rbp)
0x10a402a1d <+157>: movq -0x30(%rbp), %rcx
0x10a402a21 <+161>: movq %rdi, -0x70(%rbp)
0x10a402a25 <+165>: movq %rcx, %rdi
0x10a402a28 <+168>: movq -0x70(%rbp), %rsi
0x10a402a2c <+172>: movq -0x28(%rbp), %rdx
0x10a402a30 <+176>: callq 0x10a402680 ; Starry.AddStudentGradeCell.init (style : __C.UITableViewCellStyle, reuseIdentifier : Swift.Optional<Swift.String>) -> Starry.AddStudentGradeCell at AddStudent.swift:384
0x10a402a35 <+181>: addq $0x70, %rsp exc_bad_instruction(code=exc_i386_invop,subcode=0x0)
0x10a402a39 <+185>: popq %rbp
0x10a402a3a <+186>: retq
最佳答案
我能够通过添加非常简单的代码行来修复我的代码。
错误代码：
else {
let cell = tableView.dequeueReusableCell(withIdentifier: gradeCell, for: indexPath) as! AddStudentGradeCell
cell.textLabel!.text = self.array[indexPath.row]
cell.selectionStyle = UITableViewCellSelectionStyle.none
cell.addStudentGradeTextField?.inputView = pickerGrade
cell.addStudentGradeTextField.placeholder = grade[0]
return cell
}
好代码：
else {
let cell = tableView.dequeueReusableCell(withIdentifier: gradeCell, for: indexPath) as! AddStudentGradeCell
cell.textLabel!.text = self.array[indexPath.row]
cell.selectionStyle = UITableViewCellSelectionStyle.none
cell.addStudentGradeTextField.inputView = pickerGrade
cell.addStudentGradeTextField.placeholder = grade[0]
addStudentGradeTextField = cell.addStudentGradeTextField
return cell
}
关于ios - Swift:从UIPickerView中选择后，TextField不更新，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42063847/