ios - 向上推软键盘时如何改变UIScrollView内容的高度

Question

我有一个带有 TextView 和按钮的 View ，就像在任何典型的消息传递应用程序中一样。当出现键盘时，textview 和按钮也被向上推，但内容被向上推离屏幕，我看不到它的顶端，但是当我用力向下滚动时，我看到它向下爬行并向上弹起当我放手时。我已经用草图说明了我遇到的问题，第三个屏幕是所需的行为。

我在 .xib 文件中有这个 View 。我有一个 View -> ScrollView -> contentView(它有一个表格、textview 和按钮)

我注册了键盘通知，这里是显示/隐藏方法的代码

- (void)registerForKeyboardNotifications {
   [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWasShown:)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillBeHidden:)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];

} 

- (void)keyboardWasShown:(NSNotification *) aNotification {
   NSDictionary *info = [aNotification userInfo];

   CGSize keyboardSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;

   // the hardcoded 49 is the height of the uitabbar 
   UIEdgeInsets contentInsets = UIEdgeInsetsMake(-keyboardSize.height+49, 0.0, keyboardSize.height-49, 0.0);
   self.scrollView.contentInset = contentInsets;
   self.scrollView.scrollIndicatorInsets = contentInsets;

   [self.view addGestureRecognizer:self.tapRecognizer];

 }


- (void)keyboardWillBeHidden:(NSNotification *) aNotification {
   UIEdgeInsets contentInsets = UIEdgeInsetsZero;
   self.scrollView.contentInset = contentInsets;
   self.scrollView.scrollIndicatorInsets = contentInsets;

   [self.view removeGestureRecognizer:self.tapRecognizer];
}

Answer 1

我在 keyboardWasShown 方法中看到了这一行

UIEdgeInsets contentInsets = UIEdgeInsetsMake(-keyboardSize.height+49, 0.0, keyboardSize.height-49, 0.0);

顶部边缘插入的位置是 -ve，因为 49 - keyboardSize(约为 256)。将其替换为:

UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, (keyboardSize.height-49), 0.0);

玩最适合您的计算。希望这项工作:)