android 应用架构随笔三（ListView）

import java.util.ArrayList;
import java.util.List;
 
import com.heima.googleplay.holder.BaseHolder;
import com.heima.googleplay.holder.MoreHolder;
import com.heima.googleplay.manager.ThreadManager;
import com.heima.googleplay.utils.UIUtils;
 
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView.RecyclerListener;
import android.widget.BaseAdapter;
import android.widget.ListView;
 
public abstract class MyBaseAdapter<T> extends BaseAdapter implements
        RecyclerListener {
 
    public ListView mListView;
 
    public MyBaseAdapter(ListView mListView, List<T> mDatas) {
        this.mListView = mListView;
        // 初始化一个界面可见的holder
        mDisplayHolderLists = new ArrayList<BaseHolder>();
 
        if (null != mListView) {
            // 设置listview的回收监听
            mListView.setRecyclerListener(this);
        }
        setData(mDatas);
    }
 
    public List<T> mDatas;
    private BaseHolder holder;
    private List<BaseHolder> mDisplayHolderLists;
 
    public void setData(List<T> mDatas) {
        this.mDatas = mDatas;
 
    }
 
    public List<T> getData() {
        return mDatas;
    }
 
    @Override
    public int getCount() {
        // +1 表示添加一个特殊的条目
        return mDatas.size() + 1;
    }
 
    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return mDatas.get(position);
    }
 
    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }
 
    // 表示加载更多
    private final int MORE_ITEM_TYPE = 0;
    // 表示普通的数据类型
    private final int ITEM_VIEW_TYPE = 1;
    private MoreHolder moreHolder;
 
    /**
     * 获取到item的类型
     *
     * @param position
     * @return
     */
    @Override
    public int getItemViewType(int position) {
        // 判断当前是否是最后一个条目
        if (position == getCount() - 1) {
            return MORE_ITEM_TYPE;
        } else {
            return getInnerItemViewType(position);
        }
    }
 
    public int getInnerItemViewType(int position) {
        // TODO Auto-generated method stub
        return ITEM_VIEW_TYPE;
    }
 
    /**
     * 获取到一共有多少中数据类型
     *
     * @return
     */
    @Override
    public int getViewTypeCount() {
        return super.getViewTypeCount() + 1;
    }
 
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView != null) {
            holder = (BaseHolder) convertView.getTag();
        } else {
            if (getItemViewType(position) == MORE_ITEM_TYPE) {
                holder = getMoreHolder();
            } else {
                holder = getHolder();
            }
 
        }
        if (getItemViewType(position) == ITEM_VIEW_TYPE) {
            holder.setData(mDatas.get(position));
        }
 
        // 把所有的holder全部丢入mDisplayHolderLists
        mDisplayHolderLists.add(holder);
        return holder.getRootView();
    }
    /**
     * 获取更多的holder
     * @return
     */
    private BaseHolder getMoreHolder() {
        if(moreHolder == null){
            moreHolder = new MoreHolder(hasMore(),this);
        }
 
        return moreHolder;
    }
    /**
     * 表示有更多的数据
     * @return
     */
    public boolean hasMore() {
        // TODO Auto-generated method stub
        return true;
    }
 
    public abstract BaseHolder getHolder();
 
    /**
     * 当listview回收的时候调用当前的方法
     */
    @Override
    public void onMovedToScrapHeap(View view) {
        System.out.println("我被回收了.....");
        if (null != view) {
            BaseHolder holder = (BaseHolder) view.getTag();
            if (null != holder) {
                synchronized (mDisplayHolderLists) {
                    mDisplayHolderLists.remove(holder);
                }
 
            }
        }
 
    }
    private boolean isLoading = false;
    /**
     * 加载更多
     */
    public void loadMore() {
        if(!isLoading){
            isLoading = true;
            ThreadManager.getLongPool().execute(new Runnable() {
 
                @Override
                public void run() {
                    final List list =  onLoadMore();
                    UIUtils.runInMainThread(new Runnable() {
 
                        @Override
                        public void run() {
                            if(null == list){
                                //如果服务器返回的数据等于null。那么设置一个错误状态
                                getMoreHolder().setData(MoreHolder.ERROR);
                            }else if(list.size() < 20){
                                //如果服务器返回的数据小于20条。那么设置没有更多数据的状态
                                getMoreHolder().setData(MoreHolder.NO_MORE);
                            }else{
                                getMoreHolder().setData(MoreHolder.HAS_MORE);
                            }
 
                            if(null != list){
                                if(null !=mDatas){
                                    mDatas.addAll(list);
                                }else{
                                    setData(list);
                                }
                            }
                            //刷新界面
                            notifyDataSetChanged();
                            isLoading = false;
                        }
                    });
 
                }
            });
        }
 
    }
 
    protected abstract List onLoadMore();
 
}

MyBaseAdapter

package com.heima.googleplay.widget;
 
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
 
import com.heima.googleplay.R;
import com.heima.googleplay.manager.ThreadManager;
import com.heima.googleplay.utils.UIUtils;
 
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.FrameLayout;
/**
 *
 *
 * ============================================================
 **/
public abstract class LoadingPage extends FrameLayout {
    //默认状态
    private final int UN_LOADING  =  1;
    //加载状态
    private final int LOADING = 2;
    //加载失败状态
    private final int ERROR = 3;
    //加载成功。然后服务器没有返回数据
    private final int EMPTY = 4;
    //加载成功的状态
    private final int SUCCESS = 5;
    //用来记录某种状态
    private int mState;
    private View mLoadingView;
    private View mErrorView;
    private View mEmptyView;
 
    private View mSuccessView;
    public LoadingPage(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }
 
    private void init() {
        //首先赋值
        mState = UN_LOADING;
 
        mLoadingView = createLoadingView();
 
        if(null != mLoadingView){
            addView(mLoadingView, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
        }
 
        mErrorView = createErrorView();
 
        if(null != mErrorView){
            addView(mErrorView,new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
        }
 
        mEmptyView = createEmptyView();
 
        if(null != mEmptyView ){
            addView(mEmptyView, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
        }
 
        showSafePage();
 
    }
 
    private void showSafePage() {
        UIUtils.runInMainThread(new Runnable() {
 
            @Override
            public void run() {
                showPage();
 
            }
        });
 
    }
 
    protected void showPage() {
        if(null != mLoadingView){
            mLoadingView.setVisibility(mState == UN_LOADING || mState ==  LOADING ? View.VISIBLE : View.INVISIBLE);
        }
 
        if(null != mErrorView){
            mErrorView.setVisibility(mState == ERROR ? View.VISIBLE : View.INVISIBLE);
        }
 
        if(null != mEmptyView){
            mEmptyView.setVisibility(mState == EMPTY ? View.VISIBLE : View.INVISIBLE);
        }
 
        if(null == mSuccessView && mState == SUCCESS ){
            mSuccessView = createSuccessView();
            addView(mSuccessView, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
        }
        if(null != mSuccessView){
            mSuccessView.setVisibility(mState == SUCCESS ? View.VISIBLE : View.INVISIBLE);
        }
    }
 
    public abstract View createSuccessView();
 
    private View createEmptyView() {
        // TODO Auto-generated method stub
        return UIUtils.inflate(R.layout.loading_page_empty);
    }
 
    private View createErrorView() {
        // TODO Auto-generated method stub
        return UIUtils.inflate(R.layout.loading_page_error);
    }
 
    private View createLoadingView() {
        // TODO Auto-generated method stub
        return UIUtils.inflate(R.layout.loading_page_loading);
    }
 
    public LoadingPage(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }
 
    public LoadingPage(Context context) {
        super(context);
        init();
    }
//    //加载失败状态
//        private final int ERROR = 3;
//        //加载成功。然后服务器没有返回数据
//        private final int EMPTY = 4;
//        //加载成功的状态
//        private final int SUCCESS = 5;
    public enum LoadResult{
        ERROR(3),EMPTY(4),SUCCESS(5);
        int value ;
        LoadResult(int value){
            this.value = value;
        }
        public int getValue() {
            return value;
        }
    }
 
    private class LoadTask implements Runnable{
 
        @Override
        public void run() {
            final LoadResult result = Load();
            UIUtils.runInMainThread(new Runnable() {
 
                @Override
                public void run() {
 
                    mState = result.getValue();
 
                    showPage();
                }
            });
 
        }
 
    }
 
    public void show() {
        if(mState == ERROR || mState == EMPTY){
            mState = UN_LOADING;
        }
 
        if(mState == UN_LOADING){
            mState = LOADING;
 
            LoadTask task = new LoadTask();
            ThreadManager.getLongPool().execute(task);
//            ExecutorService service = Executors.newFixedThreadPool(3);
//            LoadTask task = new LoadTask();
//            service.execute(task);
        }
        showSafePage();
    }
 
    public abstract LoadResult Load() ;
 
}

LoadingPage