ViewPager.setOffscreenPageLimit(0)按预期的方式不起作用不起作用、方式、ViewPager、setOffscreenPageLimit

2023-09-11 20:11:30 作者:请了跟我走吗

我用我的 ViewPager 实例都相当耗费资源的片段,所以我只希望加载一次。当我尝试以下方法:

  mViewPager.setOffscreenPageLimit(0);
mViewPager.setAdapter(mPagerAdapter);
 

我的 FragmentStatePagerAdapter.getItem(INT位置)替代函数被调用的3倍,这是当我打电话会发生什么 mViewPager.setOffscreenPageLimit(1) 。我希望它只能被调用一次,因为我指定的0屏幕外的页面。

我相信我正确地调用一切,因为如果我叫 mViewPager.setOffscreenPageLimit(2) FragmentStatePagerAdapter.getItem(INT位置)被称为5次,因为我期望的那样。

是否ViewPager至少需要1屏幕外的页面,还是我做错了什么吗?

解决方案   

是否ViewPager至少需要1屏幕外页

是的。如果我正确读取源$ C ​​$ C,你应该得到的LogCat中有关此警告,是这样的:

 请求的屏幕外的页数限制0过小;默认为1
 

ViewPager2踩坑

The fragments I use in my ViewPager instance are quite resource intensive, so I'd only like to load one at a time. When I try the following:

mViewPager.setOffscreenPageLimit(0);
mViewPager.setAdapter(mPagerAdapter);

My FragmentStatePagerAdapter.getItem(int position) override function is called 3 times, which is what happens when I call mViewPager.setOffscreenPageLimit(1). I would expect it to only be called once, because I specified 0 offscreen pages.

I believe I'm calling everything correctly, because if I call mViewPager.setOffscreenPageLimit(2), FragmentStatePagerAdapter.getItem(int position) is called 5 times as I would expect.

Does ViewPager require a minimum of 1 offscreen pages, or am I doing something wrong here?

解决方案

Does ViewPager require a minimum of 1 offscreen pages

Yes. If I am reading the source code correctly, you should be getting a warning about this in LogCat, something like:

Requested offscreen page limit 0 too small; defaulting to 1