在iPhone開發筆記(5)scrollView和pageControl的搭配使用中忽略了UIScrollView的邊界處理問題。在UIScrollView中有一個重要的屬性bounces,下面是蘋果的開發文檔中對這個屬性的定義。
bounces
A Boolean value that controls whether the scroll view bounces past the edge of content and back again.
Discussion
If the value of this property is YES
, the scroll view bounces when it encounters a boundary of the content. Bouncing visually indicates that scrolling has reached
an edge of the content. If the value is NO
, scrolling stops immediately at the content boundary without bouncing. The default value is YES
.
Availability
- Available in iOS 2.0 and later.
(1)當bounces屬性設置爲YES時,當UIScrollView中圖片滑動到邊界的時候會出現彈動的效果,就像是Linux中的果凍效果一樣。
(2)當bounces屬性設置爲NO時,當UIScrollView中圖片滑動到邊界時會直接定在邊界就不會有彈動的效果。
我將bounces屬性設置爲NO,這樣就解決了一個bug。就是在滑動到最左端的圖片時,再向左滑動就滑動不了,向右滑動也是一樣的道理。這樣就解決了數組越界所導致的崩潰問題。