UIScrollView中的UITextView不显示长文本

Question

I have a UITextView inside a UIScrollView. if I try to display a long text with a certain font size, the text is not showing. With shorter text or decreasing the font size the text shows up again. What am I doing wrong?

Screenshot of the autolayout here (the item selected is the textview):

Answer 1

The UITextView is inherited from UIScrollView

open class UITextView : UIScrollView, UITextInput, UIContentSizeCategoryAdjusting

So it is a bad practice to put ScrollView inside scrollView. The reason why you don't see a long text in UITextView is that UITextView became scrollable. Also you didn't specify your scrollView content width so the with is calculated is as one line of your long text. But you can scroll it because you will scroll scrollView. Better way is to set label inside scrollview and set the label numberOfLines = 0. Make the label bottom padding to the bottom of your scrollView and top to some items in top of label and you will get a scrollable text.

I've just understood that you don't need a scrollView to place your long text.

You can use just a UITextView for your needs.

1. Remove your scrollView.
2. Add a UITextView.
3. Set constraints as described and math them with screenshot
   • Top Space to ReadingTimeLabel
   • Align Bottom to Superview / Bottom Layout Guide
   • Leading space to Superview
   • Trailing space to Superview

And you will get the result like on the screenshots

Scroller top:

Scrolled bottom:

Note: You can disable UITextView editing in attribute inspector.

But if you for some reason need a scroll view: Set constrains as described, also match them as shown on screenshots.

1. Add scrollView constraints (Superview is the view where the scrollView is placed in): -Top space to ReadingTimeLabel -Align bottom to Superview/Bottom Layout Guide -Align leading to Superview -Align trailing to Superview

2. Please a UIView inside scrollView. Use it as container.

3. Add constraints for container. (Superview is scrollView) -Align Leading to Superview -Align Trailing to Superview -Top Space to SuperView -Bottom Space to SuperView -Equal Width to SuperView

4. Add a UILabel inside container. (Superview is container).

5. Add constraints for UILabel. -Align Leading to Superview -Align Trailing to Superview -Top Space to SuperView -Bottom Space to SuperView

6. For the label set Lines = 0 in Attribute inspector or use the code

label.numberOfLines = 0

And you will get the result like on screenshots

Scrolled top

Scroller bottom

Answer 2

试试下面的代码：

textView.sizeToFit()