介绍
最近用淘宝客户端的时候，编辑地址的时候有个地区选择的功能。看上面的效果觉得挺酷，滚动的时候，是最后一个从下面飞上来挨着前一个。就自己鼓捣一个出来玩玩。
说了效果可能不太直观，下面上两张图看看效果
淘宝地区选择效果
再来一张自己的效果
gif的效果可能不太好，大家自己用Android手机打开淘宝看看
实现分析
展示很简单，ListView就可以了。对于动画效果，只需要在getView的时候获取到要展示的View，通过属性动画修改translationY就ok啦。由于地区选择是一个界面，所以这里还用到了Fragment的 addToBackStack知识
1、用来展示的Fragment
用一个Fragment来接受parentCode参数来获取父地区的所有子地区，然后进行显示。这里用Fragment来做是因为用Activity的话，这样的连续点击都是同一类的界面不太适合。
public class AreaFragment extends Fragment implements AdapterView.OnItemClickListener {
private static final String ARG_PARAM1 = "parentCode";
@Bind(R.id.refresh_list_view)
ListView mRefreshListView;
@Bind(R.id.loadingBar)
ProgressBar mLoadingBar;
private String mParam1;//parentCode参数
OkHttpClient mOkHttpClient = new OkHttpClient();
private OnFragmentInteractionListener mListener;
private AreaAdapter adapter;//地区adapter
public AreaFragment() {
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @return A new instance of fragment AreaFragment.
*/
public static AreaFragment newInstance(String param1) {
AreaFragment fragment = new AreaFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
//获取父地区的code，用来查询子地区
mParam1 = getArguments().getString(ARG_PARAM1);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_area, container, false);
ButterKnife.bind(this, view);
mRefreshListView.setOnItemClickListener(this);
FormEncodingBuilder builder = new FormEncodingBuilder();
builder.add(ARG_PARAM1,mParam1);
//通过parentCode来请求地区，如果parentCode不存在就是第一级
final Request request = new Request.Builder()
.url("http://123.184.16.19:8008/area/list")
.post(builder.build())
.build();
mOkHttpClient.newCall(request).enqueue(new Callback(){
@Override
public void onFailure(Request request, IOException e) {
}
@Override
public void onResponse(Response response) throws IOException {
final String res = response.body().string();
if (res!=null){
Gson gson = new Gson();
JsonResult jsonResult = gson.fromJson(res, JsonResult.class);
if (jsonResult.isSuccess()){
List list = (List) jsonResult.getResult();
List newList = new ArrayList();
Iterator iterator = list.iterator();
while (iterator.hasNext()){
Map map = (Map) iterator.next();
AreaInfo areaInfo = gson.fromJson(gson.toJson(map),AreaInfo.class);
newList.add(areaInfo);
}
adapter = new AreaAdapter(getContext(),newList);
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
//拿到数据进行展示
mRefreshListView.setAdapter(adapter);
}
});
}
}
}
});
return view;
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
@Override
public void onDestroyView() {
super.onDestroyView();
ButterKnife.unbind(this);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//单击的时候需要处理地区点击事件，统一交给Activity处理
AreaInfo areaInfo = (AreaInfo) parent.getAdapter().getItem(position);
if (areaInfo==null) return;
if (mListener!=null){
mListener.onFragmentInteraction(areaInfo);
}
}
//用来和Activity交互的回调接口
public interface OnFragmentInteractionListener {
void onFragmentInteraction(AreaInfo areaInfo);
}
我们用了一个Fragment来接受parentCode，用于请求下一级的地区，获取成功之后进行了展示。并且提供了一个OnFragmentInteractionListener用来在onItemClick时与Activity交互。
接下来看adapter,最开始我们提到了要实现淘宝的效果我们只需要拿到即将显示的View，设置动画就可以了。
2、处理显示效果的adapter
class AreaAdapter extends BaseAdapter {
private List list;
private int lastPosition;
public AreaAdapter(Context context, List<AreaInfo> list) {
this.list = list;
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
if (convertView==null){
convertView = LayoutInflater.from(getContext()).inflate(R.layout.area_list_item,parent,false);
viewHolder = new ViewHolder();
viewHolder.textView = (TextView) convertView.findViewById(android.R.id.text1);
convertView.setTag(viewHolder);
}
viewHolder = (ViewHolder) convertView.getTag();
AreaInfo item = (AreaInfo) list.get(position);
viewHolder.textView.setText(item.getAreaName());
if (lastPosition<position&&lastPosition!=0){
ObjectAnimator.ofFloat(convertView,"translationY",convertView.getHeight()*2,0).setDuration(500).start();
}
lastPosition = position;
return convertView;
}
class ViewHolder{
TextView textView;
}
}
很常见的一个Adapter写法，只是在getView当中获取到了要显示的view，通过
ObjectAnimator.ofFloat(convertView,"translationY",convertView.getHeight()*2,0).setDuration(500).start()为veiw设置了动画，
这里还用了个变量position来区别只有在向上滚动的时候才会有动画。不过我觉得不加position区别的效果也不错，大家可以试试。
其实这样已经实现了效果，接下来顺便提一下Activity对Framgnet中onItemClick的处理。
3、Activity和fragment的交互处理
public class AreaSelectActivity extends AppCompatActivity implements AreaFragment.OnFragmentInteractionListener{
private Fragment oneFragment;
private Fragment twoFragment;
private Map map = new HashMap();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_area_select);
ButterKnife.bind(this);
//新建第一级地区，parentCode参数为null
oneFragment = AreaFragment.newInstance("");
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content,oneFragment).commit();
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case android.R.id.home:
FragmentManager fragmentManager = getSupportFragmentManager();
if (fragmentManager.getBackStackEntryCount()>0){
fragmentManager.popBackStack();
}else{
finish();
}
break;
}
return true;
}
/**
* 处理交互，hide前一个fragment，并且调用addToBackStack让Fragment可以点击back的时候显示前一个fragment
* 如果是第三级地区则直接返回地区选择数据给上个Activity
* @param areaInfo 被点击的地区信息
*/
@Override
public void onFragmentInteraction(AreaInfo areaInfo) {
if (areaInfo==null){
return;
}
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
int level = areaInfo.getLevel();
switch (level){
case 1:
map.put("provId",areaInfo.getId());
map.put("provName",areaInfo.getAreaName());
if (areaInfo.isLeaf()){
Intent intent = new Intent();
intent.putExtra("addressInfo", (Serializable) map);
setResult(RESULT_OK,intent);
finish();
}else{
transaction.hide(oneFragment);
transaction.add(R.id.content,twoFragment=AreaFragment.newInstance(areaInfo.getAreaCode()+"")).addToBackStack(null).commit();
}
break;
case 2:
map.put("cityId",areaInfo.getId());
map.put("cityName",areaInfo.getAreaName());
if (areaInfo.isLeaf()){
Intent intent = new Intent();
intent.putExtra("addressInfo", (Serializable) map);
setResult(RESULT_OK,intent);
finish();
}else {
transaction.hide(twoFragment);
transaction.add (R.id.content, AreaFragment.newInstance(areaInfo.getAreaCode()+"")).addToBackStack(null).commit();
}
break;
case 3:
map.put("districtId",areaInfo.getId());
map.put("districtName",areaInfo.getAreaName());
Intent intent = new Intent();
intent.putExtra("addressInfo", (Serializable) map);
setResult(RESULT_OK,intent);
finish();
break;
}
}
}
这样仿淘宝地区选择就实现啦！
结语
大家可以自己写测试接口，也可以直接调用我写好的接口：
http://123.184.16.19:8008/area/list
源码提供给大家参考:
Android仿淘宝地区选择
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