Question

我正在尝试根据内容和＆amp ;;调整文本视图的大小它也是兄弟姐妹和父容器。

以下代码在iOS 6中正常运行

   if (/* less than ios 7 */) {
        CGRect frame = _textView.frame;
        CGSize conSize = _textView.contentSize;
        CGFloat difference = conSize.height - frame.size.height;

        frame.size.height += difference;
        _textView.frame = frame;

        UIScrollView *parentView = (UIScrollView *)_textView.superview;
        // adjust views residing below this text view.

        // sibling view
        UIView *belowView = // access it somehow
        CGRect frame1 = belowView.frame;

        frame1.origin.y += difference;
        belowView.frame = frame1;
        // adjust parent scroll view, increase height.
        CGSize frame3 = parentView.contentSize;

        frame3.height += difference;
        parentView.contentSize = frame3;
    } else {
       // tried
       [_textView sizeToFit]; 
       [_textView layoutIfNeeded];
       [parentView sizeToFit]; 
       [parentView layoutIfNeeded];
    }

试图关注iOS 7解决方案： How do I size a UITextView to its content on iOS 7?

但没有工作。

任何指针？

来自@NSBouzouki的工作代码解决方案

if (/* ios 7 */) {
             [_textView.layoutManager ensureLayoutForTextContainer:_textView.textContainer];
            [_textView layoutIfNeeded];
}
            CGRect frame = _textView.frame;
            CGSize conSize = _textView.contentSize;
            CGFloat difference = conSize.height - frame.size.height;

            frame.size.height += difference;
            _textView.frame = frame;

            UIScrollView *parentView = (UIScrollView *)_textView.superview;
            // adjust views residing below this text view.

            // sibling view
            UIView *belowView = // access it somehow
            CGRect frame1 = belowView.frame;

            frame1.origin.y += difference;
            belowView.frame = frame1;
            // adjust parent scroll view, increase height.
            CGSize frame3 = parentView.contentSize;

            frame3.height += difference;
            parentView.contentSize = frame3;

Answer 1

似乎UITextView's contentSize属性在iOS 7中未正确设置，直到viewDidAppear:。这可能是因为NSLayoutManager懒惰地放置了文本，并且必须为contentSize布置整个文本才是正确的。 ensureLayoutForTextContainer:方法强制提供文本容器的布局，之后可以使用usedRectForTextContainer:来获取边界。为了正确获得总宽度和高度，必须考虑textContainerInset属性。以下方法对我有用。

 - (CGRect)contentSizeRectForTextView:(UITextView *)textView
    {
        [textView.layoutManager ensureLayoutForTextContainer:textView.textContainer];
        CGRect textBounds = [textView.layoutManager usedRectForTextContainer:textView.textContainer];
        CGFloat width =  (CGFloat)ceil(textBounds.size.width + textView.textContainerInset.left + textView.textContainerInset.right);
        CGFloat height = (CGFloat)ceil(textBounds.size.height + textView.textContainerInset.top + textView.textContainerInset.bottom);
        return CGRectMake(0, 0, width, height);
    }

此外，似乎从UITextView's调用setContentSize: layoutSubviews方法。因此，在layoutIfNeeded上调用textView 之后，layoutSubviews（其本身称为ensureLayoutForTextContainer:）上调用layoutManager，应该textView's contentSize更正。

[someTextView.layoutManager ensureLayoutForTextContainer:someTextView.textContainer]; [someTextView layoutIfNeeded]; // someTextView.contentSize should now have correct value

Answer 2

GrowingTextViewHandler是一个NSObject子类，它在用户键入文本时调整文本视图的大小。以下是如何使用它。

 @interface ViewController ()<UITextViewDelegate>

 @property (weak, nonatomic) IBOutlet UITextView *textView;
 @property (weak, nonatomic) IBOutlet NSLayoutConstraint *heightConstraint;
 @property (strong, nonatomic) GrowingTextViewHandler *handler;

 @end

 @implementation ViewController

 - (void)viewDidLoad {
   [super viewDidLoad];
   self.handler = [[GrowingTextViewHandler alloc]initWithTextView:self.textView withHeightConstraint:self.heightConstraint];
   [self.handler updateMinimumNumberOfLines:3 andMaximumNumberOfLine:8];
}

 - (void)textViewDidChange:(UITextView *)textView {
   [self.handler resizeTextViewWithAnimation:YES];
}
@end

根据iOS7中的内容调整UItextview的大小

2 个答案: