以编程方式在故事板中创建的单元格中操作UITextField

Question

我正在尝试更改TableView委托中的UITextField

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if ( cell == nil ) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                      reuseIdentifier:CellIdentifier];
    }

    // Configure cell here
    if ( indexPath.section == [self nameSectionNumber]) {
        if ( indexPath.row == [self firstNameRowNumber] ){
            UITextField *textFieldFromCell = [self retrieveUITextFieldFromCell:cell];
            textFieldFromCell.text = [self.person firstName];
        } else if ( indexPath.row == [self lastNameRowNumber] ) {
            cell.textLabel.text = [self.person lastName];
        }
    } else if ( indexPath.section == [self emailSectionNumber] ) {
        if ( indexPath.row == [self emailSectionHomeRowNumber] ) {
            cell.textLabel.text = [self.person homeEmail];
        } else if ( indexPath.row == [self emailSectionWorkRowNumber] ) {
            cell.textLabel.text = [self.person workEmail];
        }
    }

    return cell;
}


- (UITextField *)retrieveUITextFieldFromCell:(UITableViewCell *)cell
{
    // Need to grab UITextField from cell
    for (UIView *view in  cell.contentView.subviews){
        if ([view isKindOfClass:[UITextField class]]){
            UITextField* txtField = (UITextField *)view;
            return txtField;
        }
    }
    return nil;
}

如果我不尝试修改单元格，只需执行

// Configure cell here
    if ( indexPath.section == [self nameSectionNumber]) {
        if ( indexPath.row == [self firstNameRowNumber] ){
            cell.textLabel.text = [self.person firstName];
        } else if ( indexPath.row == [self lastNameRowNumber] ) {
            cell.textLabel.text = [self.person lastName];
        }
    }

UILabel（“名字”）消失了，UITextField消失了，这是我所期待的，因为我认为它是因为这段代码

 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
        if ( cell == nil ) {
            cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                          reuseIdentifier:CellIdentifier];
        }

注意：忽略姓氏和电子邮件字段。我现在只专注于名字，以使其看起来正确。

Answer 1

在我看来，您正在使用静态单元格定义表格视图。在这种情况下，您不需要为tableview实现数据源委托方法，如果这样做，您基本上会覆盖在故事板中定义的静态单元格。如果您需要为这些单元格设置内容，我建议您为单元格定义一个IBOutlet，并简单地引用该出口并直接修改文本属性。

@interface ProfileViewController ()
    @property (weak, nonatomic) IBOutlet UITextField *firstNameTextField;
    @property (weak, nonatomic) IBOutlet UITextField *lastNameTextField;
@end

@implementation ProfileViewController
    - (void)viewDidLoad
    {
        [super viewDidLoad];

        self.navigationItem.rightBarButtonItem = self.editButtonItem;
        _firstNameTextField.text = @"John";
        _lastNameTextField.text = @"Smith";
    }

    ...
@end