問題描述

如何找出屏幕上實(shí)際可見的顯示視圖內(nèi)容的矩形 (CGRect).

How can I go about finding out the rect (CGRect) of the content of a displayed view that is actually visible on screen.

myScrollView.bounds

上面的代碼在沒有縮放時(shí)有效，但是一旦你允許縮放，它會(huì)在縮放比例不是 1 時(shí)中斷.

The code above works when there's no zooming, but as soon as you allow zooming, it breaks at zoom scales other than 1.

為了澄清，我想要一個(gè)包含滾動(dòng)視圖內(nèi)容的可見區(qū)域的 CGRect，相對(duì)于內(nèi)容.(即，如果它是縮放比例 2，矩形的大小將是滾動(dòng)視圖大小的一半，如果它是縮放比例 0.5，它將是兩倍.)

To clarify, I want a CGRect that contains the visible area of the scroll view's content, relative to the content. (ie. if it's a zoom scale 2, the rect's size will be half of the scroll view's size, if it's at zoom scale 0.5, it'll be double.)

推薦答案

回答我自己的問題，主要感謝 Jim Dovey 的回答，這并沒有完全解決問題，但給了我回答的基礎(chǔ):

Answering my own question, mostly thanks to Jim Dovey's answer, which didn't quite do the trick, but gave me the base for my answer:

CGRect visibleRect;
visibleRect.origin = scrollView.contentOffset;
visibleRect.size = scrollView.bounds.size;

float theScale = 1.0 / scale;
visibleRect.origin.x *= theScale;
visibleRect.origin.y *= theScale;
visibleRect.size.width *= theScale;
visibleRect.size.height *= theScale;

主要區(qū)別在于 visibleRect 的大小應(yīng)該是 scrollView.bounds.size，而不是 scrollView.contentSize 是內(nèi)容視圖的大小.還稍微簡化了數(shù)學(xué)，并沒有完全看到 isless() 的用途，它會(huì)在代碼更大時(shí)破壞代碼.

The main difference is that the size of the visibleRect ought to be scrollView.bounds.size, rather than scrollView.contentSize which is the size of the content view. Also simplified the math a bit, and didn't quite see the use for the isless() which would break the code whenever it's greater.

這篇關(guān)于獲取 UIScrollView 內(nèi)容的可見矩形的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！