Android之取消ViewPage+Fragment的预加载

Android之取消ViewPage+Fragment的预加载

用过ViewPage+Fragment组合的童鞋自然知道这个问题，没有遇到的同学祝愿你们永远不会遇到，呵呵。直接上关键代码

注释：setUserVisibleHint每次fragment显示与隐藏都会调用，他的调用顺序由于onCreate，所以需要一些常量进行判断

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private boolean mHasLoadedOnce = false; @Override     public void setUserVisibleHint(boolean isVisibleToUser) {         if (this.isVisible()) {             // we check that the fragment is becoming visible             if (isVisibleToUser && !mHasLoadedOnce && mArrayList==null) {                                                   // async http request here                 mHasLoadedOnce = true;             }         }         super.setUserVisibleHint(isVisibleToUser);     }

由于setUserVisibleHint优于onCreate调用，所以当onCreate调用完毕setUserVisibleHint就不会触发，这时需要在首个显示的fragment调用setUserVisibleHint方法

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@Override     public void onActivityCreated(Bundle savedInstanceState) {         // TODO Auto-generated method stub         setUserVisibleHint(true);         super.onActivityCreated(savedInstanceState);     }

这个是设置viewpager保留多少个显示界面

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1	pager.setOffscreenPageLimit(3);