Android--MVP架构设计Listview

MVP：Model View Presenter

Model：业务逻辑（加载数据）

View：视图（显示数据）

Presenter：中间者（绑定Model和View）

实现效果


创建View 的接口

public interface JView {
/*加载进度条*/
void showLoading();
/*显示数据*/
void showData(List<JEntityData> datas);
}

创建Model的接口

public interface JModel {
/**
* 加载数据
*/
void loadData(DataOnLoadListener listener);
/**
*加载完成的监听
*/
interface DataOnLoadListener{
void  onComplete(List<JEntityData> datas);

}
}

创建ModelImpl的接口

public class JModelImpl implements JModel{
@Override
public void loadData(DataOnLoadListener listener) {
List<JEntityData> datas=new ArrayList<JEntityData>();
datas.add(new JEntityData("NAME11111111111111",1,"123"));
datas.add(new JEntityData("NAME111222222222221",1,"123"));
datas.add(new JEntityData("NAME111222222222221",1,"123"));
datas.add(new JEntityData("NAME111222222222221",1,"123"));
datas.add(new JEntityData("NAME111222222222221",1,"123"));
datas.add(new JEntityData("NAME111222222222221",1,"123"));
datas.add(new JEntityData("NAME111222222222221",1,"123"));

//回调监听
listener.onComplete(datas);
}

}

创建Presenter接口

public class JPresenter extends BasePresenter<JView> {
//    view interface
JView mView;
//    model interface
JModel mModel =new JModelImpl();
/**
* 通过构造方法实例化mView
* */
public JPresenter(JView mView) {
this.mView = mView;
}

/*绑定view和model*/
public void fetch(){
//显示进度条
mView.showLoading();
//让Modle加载数据
if(mModel!=null){
mModel.loadData(new JModel.DataOnLoadListener() {
@Override
public void onComplete(List<JEntityData> datas) {
//给View显示
mView.showData(datas);
}
});
}
}
}

Activity代码

public class MainActivity extends MVPBaseActivity<JView,JPresenter> implements JView{
private ListView listView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView= (ListView) findViewById(R.id.listView_id);
//        listView.setAdapter(new ListViewAdapter(this));
//中间者,让他触发加载数据
//    不继承 MVPBaseActivity    new JPresenter(this).fetch();
mPresenter.fetch();
}

@Override
protected JPresenter createPresenter() {
return new JPresenter(this);
}

@Override
public void showLoading() {
Toast.makeText(this,"正在加载",Toast.LENGTH_SHORT).show();
}

@Override
public void showData(List<JEntityData> datas) {
listView.setAdapter(new ListViewAdapter(this,datas));
}

}

为了防止View进程在Model（加载数据）未完成时，View被回收。需要将actvity继承MVPBaseActivity以及persenter继承BasePersenter 代码如下：

BasePresenter代码

public abstract class BasePresenter<T> {
/*
* 当内存不足可释放内存
* */
protected WeakReference<T> mViewRef;
/*
* 绑定presenter View
* */
public void attchView(T view){
mViewRef=new WeakReference<T>(view);
}

/*
* 解除管理
* */
public void detachView(){
if (mViewRef!=null){
mViewRef.clear();
mViewRef=null;
}
}

protected T getView(){
return mViewRef.get();
}
}

MVPBaseActivity代码

public abstract class MVPBaseActivity<A,T extends BasePresenter<A>> extends AppCompatActivity {
protected T mPresenter;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//        创建Presenter
mPresenter=createPresenter();
//        内存泄漏
//        关联view
mPresenter.attchView((A) this);
}

@Override
protected void onDestroy() {
super.onDestroy();
//        解除关联
mPresenter.detachView();
}

protected abstract T createPresenter();
}

Adapter代码 （实现简单的2个TextView）

public class ListViewAdapter extends BaseAdapter{
private List<JEntityData> list;
private LayoutInflater inflater;
public ListViewAdapter(Context context,List<JEntityData> list) {
this.inflater=LayoutInflater.from(context);
this.list=list;
}

@Override
public int getCount() {
return list.size();
}

@Override
public Object getItem(int i) {
return list.get(i);
}

@Override
public long getItemId(int i) {
return i;
}

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder viewHolder=null;
if (view==null){
viewHolder=new ViewHolder();
view=inflater.inflate(R.layout.item_list,null);
viewHolder.name= (TextView) view.findViewById(R.id.name);
viewHolder.text= (TextView) view.findViewById(R.id.text);
view.setTag(viewHolder);
}else {
viewHolder=(ViewHolder) view.getTag();
}
viewHolder.name.setText(list.get(i).getName());
viewHolder.name.setText(list.get(i).getPhoto());
return view;
}

class ViewHolder{
TextView name;
TextView text;
}
}