ios - 无法找到文本字段的下一个响应者

Question

我正在尝试循环/导航 UITextField，我将其作为 subview 添加到 UITableViewCell。但是，我无法在 textFieldShouldReturn: 方法中获取我的 nextResponder 值。谁能告诉我我的代码哪里出错了？

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString* PlaceholderCellIdentifier = @"PlaceholderCell";

    UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:PlaceholderCellIdentifier];
    if (cell == nil)
    {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:PlaceholderCellIdentifier] autorelease];
        cell.selectionStyle = UITableViewCellSelectionStyleNone;
        cell.textLabel.font = [UIFont boldSystemFontOfSize:14];
    }

    if (indexPath.row == 0) // first name
    {
        cell.textLabel.text = @"First Name:";
        UITextField *tempFirstNameField = [[UITextField alloc]initWithFrame:CGRectMake(100, (44-18)/2, 320-100, 32)];
        self.firstNameField = tempFirstNameField;
        self.firstNameField.font = [UIFont systemFontOfSize:14];
        self.firstNameField.tag = 1;
        self.firstNameField.returnKeyType = UIReturnKeyNext;
        self.firstNameField.delegate = self;
        [tempFirstNameField release];
        [cell.contentView addSubview:self.firstNameField];
    }
    else if (indexPath.row == 1) //last name
    {
        cell.textLabel.text = @"Last Name:";
        UITextField *tempLastNameField = [[UITextField alloc]initWithFrame:CGRectMake(100, (44-18)/2, 320-100, 32)];
        self.lastNameField = tempLastNameField;
        self.lastNameField.font = [UIFont systemFontOfSize:14];
        self.lastNameField.tag = 2;
        self.lastNameField.returnKeyType = UIReturnKeyNext;
        self.lastNameField.delegate = self;
        [tempLastNameField release];
        [cell.contentView addSubview:self.lastNameField];
    }

    return cell;
}

-(BOOL)textFieldShouldReturn:(UITextField*)textField;
{
    NSInteger nextTag = textField.tag + 1;
    NSLog(@"next tag %i",nextTag);
    // Try to find next responder

    UIResponder* nextResponder = [textField.superview.superview viewWithTag:nextTag];
    //This always returns me null value
    NSLog(@"next responder %@", nextResponder);
    if (nextResponder) {
        // Found next responder, so set it.
        [nextResponder becomeFirstResponder];
    } else {
        // Not found, so remove keyboard.
        [textField resignFirstResponder];
    }
    return NO; // We do not want UITextField to insert line-breaks.
}

Answer 1

为什么你需要一个 tableView，你的字段似乎是静态的。如果内容比屏幕大，请使用简单的 ScrollView 。要循环您的字段，您可以:

1/为导航循环中所需的所有控件使用容器 View ，并简单地在 subview 中循环 NSArray

2/最佳选择。使用 NSUInteger 标签 字段设置控件获得焦点的顺序。从非零值开始，因为 0 是默认标记值。 10,11,12,13 并在您的容器 View 上使用 viewWithTag: 来检索下一个控件。