Question

我想在我的app中开发类似功能的密码。因为我正在使用textfields.Entering passocode成功完成。现在我想实现在numberpad的后退按钮操作上输入的清晰密码文本。这是我声明协议的代码片段

@objc protocol BackPressDelegate {

func backPressed(info: NSDictionary)
}

class CustomTextField: UITextField, UIKeyInput {

var del1:BackPressDelegate?

override func deleteBackward() {

        super.deleteBackward()

        if ((self.delegate?.respondsToSelector("backPressed")) != nil) {

            self.del1?.backPressed(["tag":self.tag])
        }
    }
}

为此，我创建了uitextfield的子类覆盖＆＃39; deleteBackward（）＆＃39; method.i也设置了委托故事板中的uitextfield。我的问题是deleteBackward是当我按下后退按钮时，由于某种原因没有被调用数字小。

Answer 1

试试这个子类：

// customTextField.h
#import <UIKit/UIKit.h>
@protocol customTextFieldDelegate <NSObject>
@optional
- (void)TextFieldWillDelete:(TextField*)textField;
@end

// customTextField.m
#import "customTextField.h"
@implementation customTextField

- (void)deleteBackward {
    if([[[UIDevice currentDevice] systemVersion] intValue] < 8) {
        [super deleteBackward];
    }
    if ([_deleteDelegate respondsToSelector:@selector(TextFieldWillDelete:)]){
        [_deleteDelegate TextFieldWillDelete:self];
    }
}

- (BOOL)keyboardInputShouldDelete:(TextField *)textField {
    BOOL shouldDelete = YES;

    if ([TextField instancesRespondToSelector:_cmd]) {
        BOOL (*keyboardInputShouldDelete)(id, SEL, UITextField *) = (BOOL (*)(id, SEL, UITextField *))[UITextField instanceMethodForSelector:_cmd];

        if (keyboardInputShouldDelete) {
            shouldDelete = keyboardInputShouldDelete(self, _cmd, textField);
        }
    }

    if ([[[UIDevice currentDevice] systemVersion] intValue] >= 8) {
        [self deleteBackward];
    }

    return shouldDelete;
}

// yourViewController.m
@interface yourViewController () <customTextFieldDelegate>
@end
@implementation
-(void)TextFieldWillDelete:(TextField*)textField {
    NSLog(@"will delete: %@", textField.text);
}
@end

与UITextView相同。

deleteBackward没有调用自定义UITextfield

1 个答案: