ios - 带有滚动的 UITextView 动态设置调整大小为默认值

Question

我已经实现了一个 ViewController，它有一个底部 UIView，其中包含 UITextView 并且禁用了滚动，当您在里面输入时它会调整大小。

当包含的文本高度达到 90 像素时，我启用滚动 ->

scrollEnabled = YES;

应该发生什么 UITextView 和它的 superview 应该保持它们被限制的高度(超过 90 像素限制).

会发生什么:UITextView 调整回其默认值。

更多信息: 我正在使用 Multiline UITextField 的代码作为我的底部 View 。 我正在使用 iOS7。

感谢任何帮助，谢谢。

编辑:我的代码:

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    self.textBox.scrollEnabled = NO;
    self.textBox.font = [UIFont fontWithName:@"Helvetica" size:14];
    [self registerForKeyboardNotifications];
}

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

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

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector: @selector(keyPressed:)
                                                 name: UITextViewTextDidChangeNotification
                                               object: nil];
}

- (void)keyboardWasShown:(NSNotification *)notification
{
    NSDictionary *info = [notification userInfo];
    CGSize kbSize = [info[UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    [self setViewMovedUp:YES byHeight:kbSize.height];
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    NSDictionary *info = [notification userInfo];
    CGSize kbSize = [info[UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    [self setViewMovedUp:NO byHeight:kbSize.height];
}

- (void)keyPressed:(id)sender
{
    CGRect textRect = [self.textBox.text boundingRectWithSize:CGSizeMake(255,MAXFLOAT) 
                                                      options:(NSStringDrawingUsesLineFragmentOrigin) 
                                                   attributes:@{NSFontAttributeName : [UIFont fontWithName:@"Helvetica" size:14]} 
                                                      context:nil];
    NSInteger newSizeH = textRect.size.height;
    if (self.textBox.hasText) {
        // if the height of our new chatbox is
        // below 90 we can set the height
        if (newSizeH <= 90) {
            self.textBox.scrollEnabled = NO;
            [self.textBox scrollRectToVisible:CGRectMake(0,0,1,1) 
                                     animated:NO];

            // chatbox
            CGRect chatBoxFrame = self.textBox.frame;
            chatBoxFrame.size.height = newSizeH + 12;
            self.textBox.frame = chatBoxFrame;

            // form view
            CGRect formFrame = self.commentBox.frame;
            formFrame.size.height = 30 + newSizeH;
            self.commentBox.frame = formFrame;
        }

        // if our new height is greater than 90
        // sets not set the height or move things
        // around and enable scrolling
        if (newSizeH > 90) {
            self.textBox.scrollEnabled = YES;
            CGRect frame = self.textBox.frame;
            frame.size.height = 102;
            self.textBox.frame = frame;
            CGRect formFrame = self.commentBox.frame;
            formFrame.size.height = 30 + 90;
            self.commentBox.frame = formFrame;
        }
    }
}

- (void)setViewMovedUp:(BOOL)movedUp byHeight:(CGFloat)height
{
    int movement = movedUp ? -height : height;
    [UIView animateWithDuration:0.3
                     animations:^{
                         self.dataView.frame = CGRectOffset(self.dataView.frame, 0.0, movement);
     }];  
}

Answer 1

虽然来晚了一点，但以防万一。 我自己也遇到了同样的问题。 TextView 在滚动时返回到原始大小。我解决它的方法是更新 UITextView 上的高度约束。 即每次更新 UITextView 的尺寸时，也需要更新相应的约束条件。