iOS pickerView和datePicker选择的分隔线有时显示有时不显示

UIPickerView

UIPickerView操作分隔线需要在代理方法中操作

//隐藏分割线
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    ((UILabel *)[pickerView.subviews objectAtIndex:1]).hidden = YES;//隐藏分隔线
    ((UILabel *)[pickerView.subviews objectAtIndex:2]).hidden = YES;//隐藏分隔线
    return _items[row];
}

//显示分隔线
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    ((UILabel *)[pickerView.subviews objectAtIndex:1]).backgroundColor = color;//显示分隔线
    ((UILabel *)[pickerView.subviews objectAtIndex:2]).backgroundColor = color;//显示分隔线
    return _items[row];
}

UIDatePicker

UIDatePicker可以调用下面方法来操作

//隐藏分割线
- (void)clearSpearatorLine {
    for (UIView *subView in self.datePicker.subviews) {
        if ([subView isKindOfClass:[UIPickerView class]]) {
            for (UIView *subView2 in subView.subviews) {
                if (subView2.frame.size.height < 1) {//取出分割线view
                    subView2.hidden = YES;//隐藏分割线
                }
            }
        }
    }
}

//隐藏分割线
- (void)clearSpearatorLine {
    for (UIView *subView in self.datePicker.subviews) {
        if ([subView isKindOfClass:[UIPickerView class]]) {
            for (UIView *subView2 in subView.subviews) {
                if (subView2.frame.size.height < 1) {//取出分割线view
                    subView2.backgroundColor = color;//显示分割线
                }
            }
        }
    }
}