标签:android开发
在使用AsyncTaskLoader时,当手机解锁后,会重复加载数据,代码如下:
static class CouponShopQueryLoader extends AsyncTaskLoader<List<CouponStore>> { private int couponId; public CouponShopQueryLoader(Context context, int couponId) { super(context); this.couponId = couponId; } @Override protected void onStartLoading() { forceLoad(); } @Override public List<CouponStore> loadInBackground() { //查询数据加载 } }
static class CouponShopQueryLoader2 extends AsyncTaskLoader<List<CouponStore>> { private List<CouponStore> mData; private int couponId; public CouponShopQueryLoader2(Context context, int couponId) { super(context); this.couponId = couponId; } // final ForceLoadContentObserver mObserver; /* Runs on a worker thread */ @Override public List<CouponStore> loadInBackground() { mData = ds.queryShopByCoupon(couponId, pageNo, PAGE_SIZE); return mData; } /* Runs on the UI thread */ @Override public void deliverResult(List<CouponStore> data) { if (isReset()) { return; } if (isStarted()) { super.deliverResult(data); } } /** * Starts an asynchronous load of the contacts list data. When the * result is ready the callbacks will be called on the UI thread. If a * previous load has been completed and is still valid the result may be * passed to the callbacks immediately. * * Must be called from the UI thread */ @Override protected void onStartLoading() { if (mData != null) { deliverResult(mData); } if (takeContentChanged() || mData == null) { forceLoad(); } } /** * Must be called from the UI thread */ @Override protected void onStopLoading() { Log.d("sss", "onStopLoading"); // Attempt to cancel the current load task if possible. cancelLoad(); } @Override public void onCanceled(List<CouponStore> cursor) { Log.d("sss", "onCanceled"); } @Override protected void onReset() { super.onReset(); Log.d("sss", "onReset"); // Ensure the loader is stopped onStopLoading(); mData = null; } }修改后,重复加载的现象解决了,究其原因是没有重写
/** * Must be called from the UI thread */ @Override protected void onStopLoading() { Log.d("sss", "onStopLoading"); // Attempt to cancel the current load task if possible. cancelLoad(); }
提示:在学习android开发中,官方文档其实是很好的,遵守他们的编写规范,可以使自己少走好多弯路。
标签:android开发
原文地址:http://blog.csdn.net/cml_blog/article/details/40393909