ViewPager作为一个循环队列/包装 [英] ViewPager as a circular queue / wrapping

问题描述

我使用的是 ViewPager 与 FragmentStatePagerAdapter 来让一些片段之间的导航。

I am using a ViewPager with the FragmentStatePagerAdapter to allow navigation between some fragments.

让我们说我有三个片段： A ， B 和 C 。该ViewPager显示片段A最初，并允许您通过再次刷卡从右到左，然后到C片段刷卡导航到片段B。这使得下面的导航路径： A＆LT; - ＆GT; B＆LT; - ＆GT; ç。

Let's say I have three fragments: A, B and C. The ViewPager shows Fragment A initially, and allows you to navigate to Fragment B by swiping from right-to-left, and then to Fragment C by swiping again. This allows the following navigation paths: A <--> B <--> C.

我想是能够由左到右的片段A和有ViewPager显示C片段刷卡，即它表现为一个循环队列，并允许 ... - ＆GT; C＆LT; - ＆GT; A＆LT; - ＆GT; B＆LT; - ＆GT; C＆LT; - ＆GT; A＆LT; - ...

What I would like is to be able to swipe from left-to-right on Fragment A and have the ViewPager show Fragment C, i.e. for it to behave as a circular queue and allow ... --> C <--> A <--> B <--> C <--> A <-- ...

我不想重复在其​​他位置（即结束了三个以上的情况下）。

I do not want the Fragments duplicated in other positions (i.e. ending up with more than three instances).

这是包装的功能可能有ViewPager？

Is this wrapping functionality possible with a ViewPager?

推荐答案

我已经实现了一个ViewPager / PagerAdapter，可以让伪无限分页行为。它的工作原理，通过指定一个非常大的数作为实际计数，而是将它们映射到数据集/ pageset的实际范围。它弥补一开始就受到了大批也让您可以立即从第一页面滚动到左边。

I've implemented a ViewPager/PagerAdapter that can allow for pseudo-infinite paging behaviour. It works by specifying a very large number as the actual count, but maps them to the actual range of the dataset/pageset. It offsets the beginning by a large number also so that you can immediately scroll to the left from the 'first' page.

它不工作这么好，一旦你到了100万件页（滚动时，你会看到图形毛刺），但是这通常不是一个真实的用例。我可以解决这个问题在一段时间重新计数为一个较低的数字一次，但我会离开它是怎么回事，现在。

It doesn't work so well once you get to 1,000,000th page (you will see graphical glitches when scrolling), but this is typically not a real-world use-case. I could fix this by resetting the count to a lower number once in a while, but I will leave it how it is for now.

在 InfinitePagerAdapter 包装了一个现有ViewPager，所以使用是相当透明的。该 InfiniteViewPager 也做了一些工作，以确保您可能会滚动到左侧和右侧很多次了。

The InfinitePagerAdapter wraps an existing ViewPager, and so the usage is quite transparent. The InfiniteViewPager does does a bit of work to make sure you can potentially scroll to the left and right many times.

<一个href="https://github.com/antonyt/InfiniteViewPager">https://github.com/antonyt/InfiniteViewPager

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