Question

我搜遍了S.O.获取光标当前位置的简单解决方案，然后滚动到它（假设键盘可见）。在某些情况下，大多数人似乎过于复杂和/或无效。如果光标位于键盘下方，我怎样才能每次都进行滚动工作？

Answer 1

1）确保UITextView contentInset已正确设置＆amp;在执行此操作之前，您的textView已经firstResponder了。 contentInset属性告诉textView可见区域在哪里为用户。如果键盘可见，请确保textView.contentInset.bottom属性已设置为键盘的顶部边框，否则textView可能会滚动到键盘后面不可见的空间。

见S.O.发布更多信息：What's the UIScrollView contentInset property for?

2）在我的插图准备就绪后，textView为firstResponder后，我调用以下函数：

private func scrollToCursorPositionIfBelowKeyboard() {
    let caret = textView.caretRectForPosition(textView.selectedTextRange!.start)
    let keyboardTopBorder = textView.bounds.size.height - keyboardHeight!

   // Remember, the y-scale starts in the upper-left hand corner at "0", then gets
   // larger as you go down the screen from top-to-bottom. Therefore, the caret.origin.y
   // being larger than keyboardTopBorder indicates that the caret sits below the
   // keyboardTopBorder, and the textView needs to scroll to the position.
   if caret.origin.y > keyboardTopBorder {
        textView.scrollRectToVisible(caret, animated: true)
    }
 }

可选：如果您只想滚动到光标的当前位置（假设textView目前是firstResponder而contentInset已经在此之前正确设置），只需致电：

private func scrollToCursorPosition() {
    let caret = textView.caretRectForPosition(textView.selectedTextRange!.start)
    textView.scrollRectToVisible(caret, animated: true)
 }

额外信息：要将textView滚动条设置为正确的高度，请执行以下操作修改scrollIndicatorInsets：

// This is not relative to the coordinate plane. You simply set the `.bottom` property 
// as if it were a normal height property. The textView does the rest for you.
textView.contentInset.bottom = keyboardHeight 
textView.scrollIndicatorInsets = textView.contentInset // Matches textView's visible space.

如何在UITextView中滚动到当前光标位置？

1 个答案: