如何编写自定义 UItextField 类

Question

在我的应用程序中，我需要使用很多文本字段，我真的不希望每个视图控制器类都包含可能很混乱的文本字段的代表，我只想创建一个通用类来处理文本字段的代表并返回给我一个文本字段，我可以在其中将其添加为我需要的子视图。我想把它变成一个库，并在需要文本字段时调用该类 例如

CustomTexTField *textField = [[CustomTextField alloc] initWithFrame:Frame];
// returns  a textField whose delegate will be set to CustomTextField //
// all i should do is just adding it as a subView //
[self.view addSubView:textField];

这可能吗？ 提前致谢！！

Answer 1

正如 Midhun 回答的那样，您需要创建一个自定义 TextField 类并在该类中设置委托。像这样

.h 文件

@interface CustomTextField : UITextField<UITextFieldDelegate>
@end

.m 文件

@implementation CustomTextField
- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        self.delegate = self;
    }
return self;
}
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
    return YES;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField{
}
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
    return YES;
}
- (void)textFieldDidEndEditing:(UITextField *)textField{
}
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    return YES;
}
- (BOOL)textFieldShouldClear:(UITextField *)textField{
    return YES;
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
    return YES;
}
@end

Answer 2

创建UITextField 的子类并使用它。

@interface CustomTexTField : UITextField
@end

@implementation CustomTexTField

//Add the stuffs here

@end

您可以在任何需要文本字段的地方使用：

CustomTexTField *textField = [[CustomTextField alloc] initWithFrame:customFrame];
[self.view addSubView:textField];

Answer 3

您可以通过使用块的更好方法来实现这一点：

class MyTextField: UITextField, UITextFieldDelegate {


//MARK:- PROPERTIES

var shouldPreventAllActions:Bool = false

var canCut:Bool = true
var canCopy:Bool = true
var canPaste:Bool = true
var canSelect:Bool = true
var canSelectAll:Bool = true

var blockTextFieldShouldChangeCharactersInRangeWithReplacementString:((_ textField: UITextField, _ range: NSRange, _ string: String) -> Bool)?
var blockTextFieldShouldReturn:((_ textField: UITextField) -> Bool)?
var blockTextFieldShouldClear:((_ textField: UITextField) -> Bool)?
//MARK:-
var blockTextFieldShouldBeginEditing:((_ textField: UITextField) -> Bool)?
var blockTextFieldShouldEndEditing:((_ textField: UITextField) -> Bool)?
//MARK:-
var blockTextFieldDidBeginEditing:((_ textField: UITextField) -> Void)?
var blockTextFieldDidEndEditing:((_ textField: UITextField) -> Void)?
var blockTextFieldDidEndEditingWithReason:((_ textField: UITextField, _ reason: UITextFieldDidEndEditingReason) -> Void)?


//MARK:- INIT
override init(frame: CGRect) {
    super.init(frame: frame)
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

override func awakeFromNib() {
    super.awakeFromNib()
    commonInit()
}

private func commonInit(){
    // common initialization code..
}

override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {

    if(self.shouldPreventAllActions){
        return false
    }

    switch action {
    case #selector(UIResponderStandardEditActions.cut(_:)):
        return self.canCut ? super.canPerformAction(action, withSender: sender) : self.canCut
    case #selector(UIResponderStandardEditActions.copy(_:)):
        return self.canCopy ? super.canPerformAction(action, withSender: sender) : self.canCopy
    case #selector(UIResponderStandardEditActions.paste(_:)):
        return self.canPaste ? super.canPerformAction(action, withSender: sender) : self.canPaste
    case #selector(UIResponderStandardEditActions.select(_:)):
        return self.canSelect ? super.canPerformAction(action, withSender: sender) : self.canSelect
    case #selector(UIResponderStandardEditActions.selectAll(_:)):
        return self.canSelectAll ? super.canPerformAction(action, withSender: sender) : self.canSelectAll
    default:
        return super.canPerformAction(action, withSender: sender)
    }
}

//MARK:- DELEGATE

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    if(self.blockTextFieldShouldChangeCharactersInRangeWithReplacementString != nil){
        return self.blockTextFieldShouldChangeCharactersInRangeWithReplacementString!(textField,range,string)
    }else{
        return true
    }
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {

    if(self.blockTextFieldShouldReturn != nil){
        return self.blockTextFieldShouldReturn!(textField)
    }else{
        return true
    }
}
func textFieldShouldClear(_ textField: UITextField) -> Bool {

    if(self.blockTextFieldShouldClear != nil){
        return self.blockTextFieldShouldClear!(textField)
    }else{
        return true
    }
}


//MARK:-
func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {

    if(self.blockTextFieldShouldBeginEditing != nil){
        return self.blockTextFieldShouldBeginEditing!(textField)
    }else{
        return true
    }
}
func textFieldShouldEndEditing(_ textField: UITextField) -> Bool {

    if(self.blockTextFieldShouldEndEditing != nil){
        return self.blockTextFieldShouldEndEditing!(textField)
    }else{
        return true
    }
}

//MARK:-
func textFieldDidBeginEditing(_ textField: UITextField) {

    if(self.blockTextFieldDidBeginEditing != nil){
        self.blockTextFieldDidBeginEditing!(textField)
    }
}
func textFieldDidEndEditing(_ textField: UITextField) {

    if(self.blockTextFieldDidEndEditing != nil){
        self.blockTextFieldDidEndEditing!(textField)
    }
}
func textFieldDidEndEditing(_ textField: UITextField, reason: UITextFieldDidEndEditingReason) {

    if(self.blockTextFieldDidEndEditingWithReason != nil){
        self.blockTextFieldDidEndEditingWithReason!(textField,reason)
    }
}

}

Answer 4

这对我有帮助

@interface CustomTextField : UITextField <UITextFieldDelegate> 

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.delegate = self;
    }
return self;
}

向 customTextField 类添加了委托，它对我有用。

谢谢！！