iPhone - 键盘出现时工具栏向上移动

Question

我在NavigationController中添加了一个带有TextField的工具栏

- (void)viewDidLoad
{
    // ...

    [self.navigationController setToolbarHidden:NO animated:YES];

    UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(0, 2, 240, 36)];
    textField.placeholder = @"Leave your comment here...";
    textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;

    UIBarButtonItem *commentTextFieldBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:textField];

    self.toolbarItems = [NSArray arrayWithObject:commentTextFieldBarButtonItem];
}

当用户点击TextField时，我希望工具栏随键盘向上移动。 我试过了this method。工具栏向上移动，但变空了。难道我做错了什么？请帮助我，谢谢!!

Answer 1

最佳解决方案是将inputAccessoryView设置为UITextField，如下所示：

#pragma mark - UITextFieldDelegate

-(void)textFieldDidBeginEditing:(UITextField *)textField{
   // Call the createInputAccessoryView method we created earlier.
   // By doing that we will prepare the inputAccView.

   UIView *inputAccView = [self createInputAccessoryView];
      // Now add the view as an input accessory view to the selected textfield.
   [textField setInputAccessoryView:inputAccView];  
}

---

-(UIView *)createInputAccessoryView{
  // Create the view that will play the part of the input accessory view.
  // Note that the frame width (third value in the CGRectMake method)
  // should change accordingly in landscape orientation. But we don’t care
  // about that now.
  UIView *inputAccView = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 40.0)];
  // Set the view’s background color. We’ ll set it here to gray. Use any color you want.
  [inputAccView setBackgroundColor:[[UIColor blackColor] colorWithAlphaComponent:0.20f]];
  // We can play a little with transparency as well using the Alpha property. Normally
  // you can leave it unchanged.
  [inputAccView setAlpha: 0.8];

  UIButton *btnDone = [UIButton buttonWithType:UIButtonTypeCustom];
  [btnDone setFrame:CGRectMake(240.0, 6.0f, 70.0f, 28.0f)];
  [btnDone setTitle:@"Done" forState:UIControlStateNormal];
  [btnDone setBackgroundColor:[UIColor blackColor]];
  [btnDone.layer setCornerRadius:6.0f];
  [btnDone setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
  [btnDone addTarget:self action:@selector(btnDoneForKeyboardAction:) forControlEvents:UIControlEventTouchUpInside];
  // Now that our buttons are ready we just have to add them to our view.
  [inputAccView addSubview:btnDone];

  return inputAccView;
}

---

另一种解决方案：

当视图控制器出现时，我们希望收到键盘事件的通知，以便我们可以显示工具栏以响应键盘的显示和消失：

- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}

- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];

[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}

为了响应键盘出现，我们可以从屏幕底部向上设置工具栏的动画：

- (void)keyboardWillShow:(NSNotification *)notification {
   //set your toolbar frame here for upper side
}

当键盘被解雇时，我们恰恰相反：

- (void)keyboardWillHide:(NSNotification *)notification {
   //set your toolbar frame here for down side
}