未调用UITextField委托方法

时间:2013-09-29 21:38:18

标签: ios objective-c ipad delegates ios7

所以我在UITableView的单元格中有一系列文本字段,它们位于UIViewController(不是表视图控制器)中。我可以编辑文本字段,但是 - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField等委托方法不会被调用。

视图控制器的代理集为:

@interface NRSignUpViewController : UIViewController<UITextFieldDelegate, UIPickerViewDelegate, UIPickerViewDataSource, UITableViewDelegate, UITableViewDataSource>

声明字段:

@property (nonatomic, strong) UITextField *firstName;
@property (nonatomic, strong) UITextField *lastName;
@property (nonatomic, strong) UITextField *email;

和委托在viewDidLoad中设置:

_firstName.delegate = self;
_lastName.delegate = self;
_email.delegate = self;

这是cellForRowAtIndexPath:

- (UITableViewCell *)tableView:(UITableView *)table cellForRowAtIndexPath:(NSIndexPath     *)indexPath {
    UITableViewCell *cell = [table dequeueReusableCellWithIdentifier:@"Cell"];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                      reuseIdentifier:@"Cell"];
        cell.accessoryType = UITableViewCellAccessoryNone;
    }

   UITextField *tf = [[UITextField alloc] initWithFrame:CGRectMake(10, 10, table.frame.size.width-20, 30)];
   tf.textColor = [UIColor blackColor];
   tf.returnKeyType = UIReturnKeyNext;
   switch (indexPath.row) {
       case 0:
           tf.placeholder = @"First name";
           tf.autocapitalizationType = UITextAutocapitalizationTypeWords;
           _firstName = tf;
           break;
       case 1:
           tf.placeholder = @"Last name";
           tf.autocapitalizationType = UITextAutocapitalizationTypeWords;
           _lastName = tf;
           break;
       case 2:
            tf.placeholder = @"Email address";
            tf.autocapitalizationType = UITextAutocapitalizationTypeNone;
           tf.keyboardType = UIKeyboardTypeEmailAddress;
           _email = tf;
           break;
       default:
           break;
    }

    [cell.contentView addSubview:tf];
    return cell;
}

任何可能缺少的想法?

3 个答案:

答案 0 :(得分:3)

您要在viewDidLoad中设置代理,但在cellForRow...之前不会实际创建文本字段。

答案 1 :(得分:3)

viewDidLoad方法中添加断点,并检查文本字段是否为nil。那是因为该对象尚未初始化。您应该在tableView:cellForRowAtIndexPath:方法中设置委托,因为此时它们实际上已分配。

答案 2 :(得分:1)

我想你可以试试这个:

[[NSNotificationCenter defaultCenter]
 addObserver:self
 selector:@selector(methodNothing)
 name:UITextFieldTextDidChangeNotification
 object:firstName];

您可以使用:UITextFieldTextDidBeginEditingNotificationUITextFieldTextDidEndEditingNotification