如何在Android的自定义列表视图中从TextView获取值

Question

I'm new to android development, and recently I wrote a code to show all saved contacts in an android device. For this, I used a custom list view which has 2 text views (to display contact name, contact number). It worked but now I want to get the contact name and the number (Toast message) when I click on list items. How to achieve this?

 // list item click listener
        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Toast.makeText(MainActivity.this, "Contact Name : " + contactList.get(i)  , Toast.LENGTH_SHORT).show();
            }
        });

This is the code I wrote in MainActivity.

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    ListView list;
    public String Contactname;
    public String Contactnumber;


    // array list
    final ArrayList<Contacts> contactList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        list = (ListView)findViewById(R.id.listContact);

        fetchContact(); // call fetch contact method

        // show number of contacts - toast message (testing purpose)
        int count = contactList.size();
        Toast.makeText(this, "Count : " + count , Toast.LENGTH_SHORT).show();


    }

    public void fetchContact()
    {
        Uri uri = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
        String[] projection ={ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,ContactsContract.CommonDataKinds.Phone.NUMBER};
        String selection = null;
        String[]selectionArgs = null;
        String sortOrder =null;

        ContentResolver resolver =getContentResolver();
        Cursor cursor =resolver.query(uri,projection,selection,selectionArgs,sortOrder);

        while(cursor.moveToNext()){
          Contactname =cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
          Contactnumber = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));

            Contacts contacts = new Contacts(Contactname,Contactnumber);

            contactList.add(contacts);
        }


        contactAdapter adapter = new contactAdapter(MainActivity.this,R.layout.activity_list_item,contactList);
        list.setAdapter(adapter);

        // list item click listner
        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Toast.makeText(MainActivity.this, "Contact Name : " + contactList.get(i)  , Toast.LENGTH_SHORT).show();
            }
        });
    }


}

This is the Class I used to save Contact name, number., I stored class to an array object

    public class Contacts {
        // properties
        public String name;
        public String number;

        public Contacts(String name, String number) {
            this.name = name;
            this.number = number;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getNumber() {
            return number;
        }

        public void setNumber(String number) {
            this.number = number;
        }
    }

Answer 1

You can fetch and data from textview Using Interface. For that You have to do Following Steps.

Step1: Create Interface in your contactAdapter.class File.TO create Interface You Can write.

public interface contactClickListener{
         void onContactClick(List<contact> currentContact);

}

Step2: Then after Create an Object of Interface using below statment.

contactClickListener listener;

Step3: In contactAdapter OnBindMethod First fetch Current ContactInfo Using Below Statment.

Contacts currentContact=contactList.get(position);

Step 4: Then after On Contact adapater Implement OnClick event for Textview and inside onclick Event call your interface.

listener.onContactClick(currentContact);

Step 5: Currently Your have three parameter in contactAdapter so now add One Parameter in contactAdapter class.

       contactAdapater(Existingparameter1 p1,Existingparameter2 p2,Existingparameter3 p3,contactClickListener listener){
this.listener=listener;
}

Step6: Then after Goto Your activity When You Create and call Contact Adapter. Implement Contact adapter method their using below Statement.

public class MainActivity extends AppCompatActivity implements contactadapter.OnContactClickListener{

}

Step 7: Then after change Contactadapter in activity to implement interface.

contactAdapter adapter = new contactAdapter(MainActivity.this,R.layout.activity_list_item,contactList);
    list.setAdapter(adapter);

Step8: OncontactClick method is genrated in activity where You can get all details ov textview and your contacts model class.