Question

我遇到有关光标移动的问题。我已经应用了以下解决方案，但它无法正常工作：

在ViewController.h文件中

@interface ViewController : UIViewController<WJTextFieldDelegate>

@property (weak, nonatomic) IBOutlet UITextField *textField;
@end

在ViewController.m文件中，

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(void) textFieldDidChangeSelection:(UITextField *)textField
{
    NSLog(@"Function is hit");
}

@end

UITextField的子类如下。

@interface WJTextField : UITextField
@end

@protocol WJTextFieldDelegate <UITextFieldDelegate>
- (void) textFieldDidChangeSelection: (UITextField *) textField;
@end

实现：

@implementation WJTextField

- (void) setSelectedTextRange: (UITextRange *) selectedTextRange
{
    [super setSelectedTextRange: selectedTextRange];
    if ([self.delegate respondsToSelector: @selector(textFieldDidChangeSelection:)])
        [(id <WJTextFieldDelegate>) self.delegate textFieldDidChangeSelection: self];
}

@end

但它没有击中textFieldDidChangeSelection回调。有人请帮忙吗？

请注意，我已经从以下链接检查了答案： [UITextField -- observe changes to selectedTextRange?

Answer 1

终于得到了解决方案。这是一种在textField

中检测选择的简单方法

在viewDidAppear中添加对象属性观察者

 [self.keyboardInputFieldPassword addObserver:self forKeyPath:@"selectedTextRange" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld  context:nil];

然后添加属性

的观察函数

 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
        if([keyPath isEqualToString:@"selectedTextRange"] && self.keyboardInputFieldPassword == object)
            [self textFieldDidChangeSelection:self.keyboardInputFieldPassword];
    }

这将捕获UITextField

中的选择范围

要遵循惯例，您应该在viewDidDisappear

中删除Observer

   [self.keyboardInputFieldPassword removeObserver:self forKeyPath:@"selectedTextRange" context:nil];

UITextField - 在文本选择和光标移动期间观察更改

1 个答案: