Issue with Android contact list, problem with Asynctask and setting the adapter

Currently, I am working on developing a GPS app that includes a contact list feature for connecting with other individuals. As a newcomer to Android Studio, I am encountering some challenges in resolving an issue. Initially, I successfully implemented the map and GPS functionality; however, I am now facing an error with the contact list feature.

The contact list is accessible through a popup menu triggered by the contacts button on the homepage. Unfortunately, I consistently encounter an error when attempting to access the contact list.

The error message logged is as follows: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference

Here is the snippet of the MainActivity code:

 [code snippet provided]

Additionally, here are the relevant details from the AndroidManifest file:

 [AndroidManifest details]

Moreover, I have included the SelectUser and SelectUserAdapter classes for reference:

 [SelectUser and SelectUserAdapter class details]

Lastly, the activitymaps.xml layout file and contactlist.xml and contactview.xml layout files have been included to provide a better understanding of the app's UI.

 [activitymaps.xml, contactlist.xml, and contactview.xml details]

Upon encountering the error, the stack trace generated is:

 [Error stack trace details]

javascriptjavaandroidlistviewcontacts

Answer №1

Your activitymaps.xml does not include a ListView element with the id contacts_list.

Update:

Based on the code you provided, it seems like modifying the initial lines of the "showSortPopup" function as shown below may resolve your issue:

// Inflate the popup_layout.xml
RelativeLayout viewGroup = (RelativeLayout) context.findViewById(R.id.ContactLayout);
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = layoutInflater.inflate(R.layout.contactlist, viewGroup);

selectUsers = new ArrayList<SelectUser>();
resolver = this.getContentResolver();
listView = (ListView) layout.findViewById(R.id.contacts_list);

phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + " ASC");
LoadContact loadContact = new LoadContact();
loadContact.execute();

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