我有一份工作人员需要过滤的约会清单。我正在使用Breeze控制器从数据库中提取约会。有些预约涉及多名工作人员，因此我需要深入了解预约的子实体，以便为每次预约找到工作人员。我试图根据其他地方使用ng-repeat和过滤器选择的工作人员显示一个列表，如下所示：
<section data-ng-repeat="appt in apptCtrl.appointmentList | filter: apptCtrl.matchStaff(staff)" data-ng-model="apptCtrl.appointmentList" class="apptStaffList">
<appt-event data-ng-model="appt"></appt-event>
</section>
我的约会控制器上的过滤功能如下：
self.matchStaff = function (query) {
var staffAppts = [];
angular.forEach(self.appointmentList, function (a) {
var staffAppt = a.some(function (s) {
return s.StaffId === query;
});
if (staffAppt) {
staffAppts.push(a);
}
});
return staffAppts;
};
不幸的是，在初始化控制器时会填充self.appointmentList，但直到视图加载后列表才会返回。如果没有过滤器，则只要填充列表，就会显示约会。但是，当调用matchStaff时，self.appointmentList只是一个空数组。
有没有办法在填充列表后使过滤器运行？还有其他方法来处理过滤器吗？在这种情况下，有没有办法用字符串调用过滤器？
提前感谢您的帮助！
答案 0 :(得分：1)
如果您在应用程序中使用路由，则可以使用resolve方法加载appointmentList。
FATAL EXCEPTION: main
Process: edu.gannon.gannonknightnews, PID: 3083
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.widget.TextView.getText()' on a null object reference
at edu.gannon.gannonknightnews.MenuFragment$GetNews$CustomAdapter.getView(MenuFragment.java:197)
import android.annotation.TargetApi;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
public class MenuFragment extends Fragment {
private ProgressDialog pDialog;// Progress Dialog
ListView newsList;
String my_url;
ArrayList<HashMap<String, String>> postList; //Declare Array
private static String url = "http://wangeltmg.com/GKN_ADMIN/GET_POSTS/";
GetNews.CustomAdapter CA;
// JSON Node names
private static final String TAG_ID = "id";
private static final String POST_ALLPOSTS = "posts";
private static final String POST_ID = "ID";
private static final String POST_TITLE = "post_title";
private static final String POST_CONTENT = "post_content";
private static final String GUID = "guid";
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.home, container, false);
newsList = (ListView) view.findViewById(R.id.homeListView);
TextView topic = (TextView) view.findViewById(R.id.topic);
postList = new ArrayList<HashMap<String, String>>();
//Get arguments
Bundle args = getArguments();
String mytopic = args.getString("Topic");
getActivity().getActionBar().setTitle("GannonKnightNews");
//Set topic
topic.setText(mytopic.toUpperCase());
//Execute getContacts
new GetNews().execute();
return view;
}
//Async Task
private class GetNews extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Strings", "Checking Json");
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// contacts JSONArray
JSONArray posts = null;
// Getting JSON Array node
posts = jsonObj.getJSONArray(POST_ALLPOSTS);
// looping through All Contacts
for (int i = 0; i < posts.length(); i++) {
JSONObject c = posts.getJSONObject(i);
Log.d("Post->",posts.getJSONObject(i).toString());
String id = c.getString(POST_ID);
Log.d("Post->ID",id);
String post_title = c.getString(POST_TITLE);
String post_content = c.getString(POST_CONTENT);
String guid = c.getString(GUID);
Log.d("GUID->",guid);
//String gender = c.getString(TAG_GENDER);
// tmp hashmap for single post
HashMap<String, String> post = new HashMap<String, String>();
// adding each child node to HashMap key => value
post.put(POST_ID, id);
post.put(POST_TITLE, post_title);
post.put(POST_CONTENT, post_content);
post.put(GUID, guid);
post.put("ListCount",String.valueOf(i));
// adding contact to contact list
postList.add(post);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
// Updating parsed JSON data into ListView
/*
ListAdapter adapter = new SimpleAdapter(getActivity(), postList, R.layout.list_item,
new String[] { POST_TITLE,POST_CONTENT, GUID },
new int[] {R.id.email, R.id.mobile, R.id.guid });
newsList.setAdapter(adapter);
*/
CA = new CustomAdapter( getActivity(), R.layout.list_item, postList);
newsList.setAdapter(CA);
}
public class CustomAdapter extends ArrayAdapter<HashMap<String, String>> {
private final ArrayList<HashMap<String, String>> objects;
public CustomAdapter(Context context, int resource, ArrayList<HashMap<String, String>> objects) {
//something is wrong with super
super(context, resource, objects);
this.objects = objects;
}
public View getView(int position, View convertView, ViewGroup Parent){
//convertView = new ImageView();
if(convertView == null){
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.list_item,null);
}
android.widget.ImageView postImage = (android.widget.ImageView) convertView.findViewById(R.id.img);
int getListPos = newsList.getFirstVisiblePosition();
//i set the count starting 0 and saved in the hashmap array
//to compare the first result with the first position of listview
int count = Integer.parseInt(objects.get(position).get("ListCount"));
my_url = objects.get(position).get(GUID);
if(getListPos == count) {
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.list_item_header,null);
TextView HeaderText = (TextView) convertView.findViewById(R.id.headertext);
TextView HeaderContent = (TextView) convertView.findViewById(R.id.headercontent);
HeaderText.setText(objects.get(position).get(POST_TITLE).toUpperCase());
HeaderContent.setText(objects.get(position).get(POST_CONTENT));
if(objects.get(position).get(GUID).equals("NULL")) {
postImage.setImageResource(R.drawable.default_bg);
}else{
new DownloadImageTask((ImageView) convertView.findViewById(R.id.img)).execute(my_url);
}
}
else{
//CHoose list item
//************************************************
//THe problem is in this textview which gives null object reference error
TextView thisview = (TextView) convertView.findViewById(R.id.email);
Log.d("Title", String.valueOf(thisview.getText()));
TextView postContent = (TextView) convertView.findViewById(R.id.mobile);
thisview.setText(objects.get(position).get(POST_TITLE).toUpperCase());
postContent.setText(objects.get(position).get(POST_CONTENT));
if(objects.get(position).get(GUID).equals("NULL")) {
postImage.setImageResource(R.drawable.default_bg);
}else{
new DownloadImageTask((ImageView) convertView.findViewById(R.id.img)).execute(my_url);
}
}
return convertView;
}
}//Custom Adapter
}//END getnews Async Task
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}//
}
...
//config
$routeProvider
.when('/',
{
templateUrl: "app.html",
controller: "AppCtrl"
resolve: {
appointments: function (myAppoimentsService) {
return myAppoimentsService.fetch();
}
}
}