Android 如何在片段中调用以活动作为参数的类的构造函数?
当我调用这个类的构造函数时-Android 如何在片段中调用以活动作为参数的类的构造函数?,android,android-fragments,Android,Android Fragments,当我调用这个类的构造函数时- public class FeedListAdapter extends BaseAdapter { Context mContext; public FeedListAdapter(Context mContext){ this.mContext = mContext; } private Activity activity; private LayoutInflater inflater; private List<F
public class FeedListAdapter extends BaseAdapter {
Context mContext;
public FeedListAdapter(Context mContext){
this.mContext = mContext;
}
private Activity activity;
private LayoutInflater inflater;
private List<FeedItem> feedItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public FeedListAdapter(Activity activity, List<FeedItem> feedItems) {
this.activity = activity;
this.feedItems = feedItems;
}
@Override
public int getCount() {
return feedItems.size();
}
@Override
public Object getItem(int location) {
return feedItems.get(location);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater)mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.feed_item, null);
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
TextView name = (TextView) convertView.findViewById(R.id.name);
TextView timestamp = (TextView) convertView
.findViewById(R.id.timestamp);
TextView statusMsg = (TextView) convertView
.findViewById(R.id.txtStatusMsg);
TextView url = (TextView) convertView.findViewById(R.id.txtUrl);
NetworkImageView profilePic = (NetworkImageView) convertView
.findViewById(R.id.profilePic);
FeedImageView feedImageView = (FeedImageView) convertView
.findViewById(R.id.feedImage1);
FeedItem item = feedItems.get(position);
name.setText(item.getName());
// Converting timestamp into x ago format
CharSequence timeAgo = DateUtils.getRelativeTimeSpanString(
Long.parseLong(item.getTimeStamp()),
System.currentTimeMillis(), DateUtils.SECOND_IN_MILLIS);
timestamp.setText(timeAgo);
// Chcek for empty status message
if (!TextUtils.isEmpty(item.getStatus())) {
statusMsg.setText(item.getStatus());
statusMsg.setVisibility(View.VISIBLE);
} else {
// status is empty, remove from view
statusMsg.setVisibility(View.GONE);
}
// Checking for null feed url
if (item.getUrl() != null) {
url.setText(Html.fromHtml("<a href=\"" + item.getUrl() + "\">"
+ item.getUrl() + "</a> "));
// Making url clickable
url.setMovementMethod(LinkMovementMethod.getInstance());
url.setVisibility(View.VISIBLE);
} else {
// url is null, remove from the view
url.setVisibility(View.GONE);
}
// user profile pic
profilePic.setImageUrl(item.getProfilePic(), imageLoader);
// Feed image
if (item.getImge() != null) {
feedImageView.setImageUrl(item.getImge(), imageLoader);
feedImageView.setVisibility(View.VISIBLE);
feedImageView
.setResponseObserver(new FeedImageView.ResponseObserver() {
@Override
public void onError() {
}
@Override
public void onSuccess() {
}
});
} else {
feedImageView.setVisibility(View.GONE);
}
return convertView;
}
}
公共类FeedListAdapter扩展了BaseAdapter{
语境;
公共FeedListAdapter(上下文mContext){
this.mContext=mContext;
}
私人活动;
私人充气机;
私人物品清单;
ImageLoader ImageLoader=AppController.getInstance().getImageLoader();
公共FeedListAdapter(活动,列出feedItems){
这个。活动=活动;
此项。feedItems=feedItems;
}
@凌驾
public int getCount(){
返回feedItems.size();
}
@凌驾
公共对象getItem(int位置){
返回feedItems.get(位置);
}
@凌驾
公共长getItemId(int位置){
返回位置;
}
@凌驾
公共视图getView(int位置、视图转换视图、视图组父视图){
如果(充气器==null)
充气机=(充气机)mContext
.getSystemService(上下文布局\充气机\服务);
if(convertView==null)
convertView=充气机。充气(R.layout.feed_项,空);
如果(imageLoader==null)
imageLoader=AppController.getInstance().getImageLoader();
TextView name=(TextView)convertView.findViewById(R.id.name);
TextView时间戳=(TextView)convertView
.findviewbyd(R.id.时间戳);
TextView statusMsg=(TextView)convertView
.findViewById(R.id.txtStatusMsg);
TextView url=(TextView)convertView.findViewById(R.id.txtrl);
NetworkImageView配置文件PIC=(NetworkImageView)convertView
.findviewbyd(R.id.profilePic);
FeedImageView FeedImageView=(FeedImageView)convertView
.findViewById(R.id.feedImage1);
FeedItem=feedItems.get(位置);
name.setText(item.getName());
//将时间戳转换为x ago格式
CharSequence timeAgo=DateUtils.getRelativeTimeSpanString(
Long.parseLong(item.getTimeStamp()),
System.currentTimeMillis(),DateUtils.SECOND(单位:毫秒);
timestamp.setText(timeAgo);
//空状态消息的Chcek
如果(!TextUtils.isEmpty(item.getStatus())){
statusMsg.setText(item.getStatus());
statusMsg.setVisibility(View.VISIBLE);
}否则{
//状态为空,请从视图中删除
statusMsg.setVisibility(View.GONE);
}
//正在检查空提要url
if(item.getUrl()!=null){
url.setText(Html.fromHtml(“”);
//使url可点击
setMovementMethod(LinkMovementMethod.getInstance());
setVisibility(View.VISIBLE);
}否则{
//url为空,请从视图中删除
setVisibility(View.GONE);
}
//用户档案图片
profilePic.setImageUrl(item.getProfilePic(),imageLoader);
//馈送图像
if(item.getImge()!=null){
setImageUrl(item.getImge(),imageLoader);
feedImageView.setVisibility(View.VISIBLE);
feedImageView
.setResponseObserver(新的FeedImageView.ResponseObserver(){
@凌驾
公开无效{
}
@凌驾
成功时的公共无效(){
}
});
}否则{
feedImageView.setVisibility(View.GONE);
}
返回视图;
}
}
进入这个分门别类-
public class Homepage1 extends Fragment {
private static final String TAG = MainActivity.class.getSimpleName();
private ListView listView;
private FeedListAdapter listAdapter;
private List<FeedItem> feedItems;
private String URL_FEED = "https://gist.githubusercontent.com/anonymous/e6c3336c57bf40c794ab/raw/022058ac0ceafd15bfed89a72e6b741dd84da130/blob.json";
private LinearLayout ll;
private FragmentActivity fa;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
fa = super.getActivity();
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
listView = (ListView) rootView.findViewById(R.id.list);
feedItems = new ArrayList<FeedItem>();
listAdapter = new FeedListAdapter(Homepage1, feedItems);
listView.setAdapter(listAdapter);
// We first check for cached request
Cache cache = AppController.getInstance().getRequestQueue().getCache();
Entry entry = cache.get(URL_FEED);
if (entry != null) {
// fetch the data from cache
try {
String data = new String(entry.data, "UTF-8");
try {
parseJsonFeed(new JSONObject(data));
} catch (JSONException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
} else {
// making fresh volley request and getting json
JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
URL_FEED, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
VolleyLog.d(TAG, "Response: " + response.toString());
if (response != null) {
parseJsonFeed(response);
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
});
// Adding request to volley request queue
AppController.getInstance().addToRequestQueue(jsonReq);
}
return rootView;
}
/**
* Parsing json reponse and passing the data to feed view list adapter
* */
private void parseJsonFeed(JSONObject response) {
try {
JSONArray feedArray = response.getJSONArray("feed");
for (int i = 0; i < feedArray.length(); i++) {
JSONObject feedObj = (JSONObject) feedArray.get(i);
FeedItem item = new FeedItem();
item.setId(feedObj.getInt("id"));
item.setName(feedObj.getString("name"));
// Image might be null sometimes
String image = feedObj.isNull("image") ? null : feedObj
.getString("image");
item.setImge(image);
item.setStatus(feedObj.getString("status"));
item.setProfilePic(feedObj.getString("profilePic"));
item.setTimeStamp(feedObj.getString("timeStamp"));
// url might be null sometimes
String feedUrl = feedObj.isNull("url") ? null : feedObj
.getString("url");
item.setUrl(feedUrl);
feedItems.add(item);
}
// notify data changes to list adapater
listAdapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
}
公共类Homepage1扩展了片段{
私有静态最终字符串标记=MainActivity.class.getSimpleName();
私有列表视图列表视图;
专用FeedListAdapter;
私人物品清单;
专用字符串URL_提要=”https://gist.githubusercontent.com/anonymous/e6c3336c57bf40c794ab/raw/022058ac0ceafd15bfed89a72e6b741dd84da130/blob.json";
私人线路布局;
私人碎片活动;
@凌驾
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
fa=super.getActivity();
视图根视图=充气机。充气(R.layout.fragment\u home,container,false);
listView=(listView)rootView.findViewById(R.id.list);
feedItems=新的ArrayList();
listAdapter=新的FeedListAdapter(主页1,feedItems);
setAdapter(listAdapter);
//我们首先检查缓存的请求
缓存缓存=AppController.getInstance().getRequestQueue().getCache();
Entry=cache.get(URL\u提要);
if(条目!=null){
//从缓存中获取数据
试一试{
字符串数据=新字符串(entry.data,“UTF-8”);
试一试{
parseJsonFeed(新的JSONObject(数据));
}捕获(JSONException e){
e、 printStackTrace();
}
}捕获(不支持的编码异常e){
e、 printStackTrace();
}
}否则{
//发出新的截击请求并获取json
JsonObjectRequest jsonReq=新的JsonObjectRequest(Method.GET,
URL_提要,空,新响应。侦听器(){
@凌驾
公共void onResponse(JSONObject响应){
d(标记“Response:+Response.toString());
if(响应!=null){
parseJsonFeed(响应);
}
}
},new Response.ErrorListener(){
@凌驾
公共无效onErrorResponse(截击错误){
d(标记“Error:+Error.getMessage());
}
});
//将请求添加到截击请求队列
AppController.getInstance().addToRequestQueue(jsonReq);
}
返回rootView;
}
/**
*解析json响应并将数据传递给提要视图列表适配器
* */
私有void parseJsonFeed(JSONObject响应){
试一试{
JSONArray feedArray=response.getJSONArray(“feed”);
对于(int i=0;ipublic FeedListAdapter(Activity activity, List<FeedItem> feedItems) {...}
listAdapter = new FeedListAdapter(getActivity(), feedItems);
listAdapter = new FeedListAdapter(fa, feedItems);