如何在 UITextView 中丢失空白 / 填充？

Question

I have a UITextView in my iOS Application, which displays a large amount of text. I am then paging this text by using the offset margin parameter of the UITextView. My problem is that the padding of the UITextView is confusing my calculations as it seems to be different depending on the font size and typeface that I use.

Therefore, I pose the question: Is it possible to remove the padding surrounding the content of the UITextView?

Look forward to hearing your responses!

转载于:https://stackoverflow.com/questions/746670/how-to-lose-margin-padding-in-uitextview

Answer 1

For 2018

It is one of the silliest bugs in iOS.

The class UITextViewFixed is a usually a reasonable solution.

Here is the class:

@IBDesignable class UITextViewFixed: UITextView {
    override func layoutSubviews() {
        super.layoutSubviews()
        setup()
    }
    func setup() {
        textContainerInset = UIEdgeInsets.zero
        textContainer.lineFragmentPadding = 0
    }
}

Don't forget to turn off scrollEnabled in the Inspector!

1. The solution does work properly in storyboard

2. The solution does work properly at runtime

That's it, you're done.

In general, that should be all you need in most cases.

Even if you are changing the height of the text view on the fly this usually does all you need.

(A common example of changing the height on the fly, is changing it as the user types.)

Here is the broken UITextView from Apple...

Here is UITextViewFixed:

Note that of course you must

turn off scrollEnabled in the Inspector!

Don't forget to turn off scrollEnabled! :)

---

Some further issues

(1) In some unusual cases - example, some cases of flexible cell height table views with dynamically changing height - Apple does the most infuriating thing in the world: they add extra space at the bottom. No, really! This would have to be one of the most infuriating things in iOS.

Here is a "quick fix" to add which often helps with that madness.

...
        textContainerInset = UIEdgeInsets.zero
        textContainer.lineFragmentPadding = 0

        // this is not ideal, but you can sometimes use this
        // to fix the "space at bottom" insanity
        var b = bounds
        let h = sizeThatFits(CGSize(
           width: bounds.size.width,
           height: CGFloat.greatestFiniteMagnitude)
       ).height
       b.size.height = h
       bounds = b
 ...

(2) Sometimes, to fix yet another subtle Apple mess-up, you have to add this:

override func setContentOffset(_ contentOffset: CGPoint, animated: Bool) {
    super.setContentOffset(contentOffset, animated: false)
}

(3) Arguably, we should be adding :

contentInset = UIEdgeInsets.zero

just after .lineFragmentPadding = 0 in UITextViewFixed . However ... it just doesn't work in current iOS! It may be necessary to add that in the future.

The fact that UITextView is totally broken in iOS is one of the weirdest things in all of mobile computing.

Finally, here's a somewhat similar tip for TextField: https://stackoverflow.com/a/43099816/294884