ios - 如何在底部的文本字段内设置单行？

Question

这是我在文本字段类别中使用的代码:该行仅在用户触摸 textField 时显示。

 @implementation UITextField (textField)

            -(void)textBottomLine:(UITextField *)textField
            {
                CALayer *border = [CALayer layer];
                CGFloat borderWidth = 2;
                border.borderColor = [UIColor colorFromHexString:@"#ffc400"].CGColor;
                border.frame = CGRectMake(0, textField.frame.size.height - borderWidth, textField.frame.size.width, 4);
                border.borderWidth = borderWidth;
                [textField.layer addSublayer:border];
                textField.layer.masksToBounds = YES;
         }

但我一无所获，请任何人帮助我找出解决方案。

Answer 1

您需要创建一个自定义 TextField 类并在该类中设置委托(delegate)。像这样

.h 文件

@interface CustomTextField : UITextField<UITextFieldDelegate>
@propery(strong)CALayer *border;
@end

.m 文件

@implementation CustomTextField
@synthesis border;


- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        self.delegate = self;
    }
return self;
}
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
    border = [CALayer layer];
    CGFloat borderWidth = 2;
    border.borderColor = [UIColor colorFromHexString:@"#ffc400"].CGColor;
    border.frame = CGRectMake(0, textField.frame.size.height - borderWidth, textField.frame.size.width, 4);
    border.borderWidth = borderWidth;
    [textField.layer addSublayer:border];
    textField.layer.masksToBounds = YES;
    return YES;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField{
}
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
    return YES;
}
- (void)textFieldDidEndEditing:(UITextField *)textField{
 [border removeFromSuperlayer];
}
- (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

在任何需要文本字段的地方都可以使用:

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

也许它会对你有所帮助。