版权声明：本文为博主原创文章，转载请标明出处。 https://blog.csdn.net/chaoyu168/article/details/79217223

基类：

package fragment;import android.support.v4.app.Fragment;
import android.view.View;/*** Created by xiaobai on 2018/1/31/031.*/public abstract class BaseFragment extends Fragment {/*** Fragment当前状态是否可见*/public boolean isVisible;/*** inflate布局文件 返回的view*/public View mView;/*** 简化 findViewById** @param viewId* @param <T>* @return*/protected <T extends View> T find(int viewId) {return (T) mView.findViewById(viewId);}/*** setUserVisibleHint是在onCreateView之前调用的* 设置Fragment可见状态*/@Overridepublic void setUserVisibleHint(boolean isVisibleToUser) {super.setUserVisibleHint(isVisibleToUser);/*** 判断是否可见*/if (getUserVisibleHint()) {isVisible = true;onVisible();} else {isVisible = false;onInvisible();}}/*** 可见*/private void onVisible() {lazyLoad();}/*** 不可见*/private void onInvisible() {}/*** 延迟加载* 子类必须重写此方法*/public abstract void lazyLoad();
}

应用：

package fragment;import android.content.pm.ApplicationInfo;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;import com.android.xiaobai.R;import java.util.List;/*** Created by xiaobai on 2018/1/31/031.*/public class AppFragment extends BaseFragment {/*** 标志位，标志已经初始化完成*/private boolean isPrepared;/*** 是否已被加载过一次，第二次就不再去请求数据了*/private boolean mHasLoadedOnce;private List<ApplicationInfo> mAppList;private ListView lv;@Nullable@Overridepublic View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {if (mView == null) {// 需要inflate一个布局文件 填充FragmentmView = inflater.inflate(R.layout.fragment_app, container, false);initView();isPrepared = true;
//        实现懒加载lazyLoad();}//缓存的mView需要判断是否已经被加过parent， 如果有parent需要从parent删除，要不然会发生这个mView已经有parent的错误。ViewGroup parent = (ViewGroup) mView.getParent();if (parent != null) {parent.removeView(mView);}return mView;}/*** 初始化控件*/private void initView() {lv = find(R.id.lv);}@Overridepublic void lazyLoad() {if (!isPrepared || !isVisible || mHasLoadedOnce) {return;}//填充各控件的数据mHasLoadedOnce = true;}
}