如何将数据从 Arraylist 显示到自定义 ArrayAdapter

Question

我正在开发一个应用程序，我需要从通讯录中获取所有联系人并显示。我希望用户选择一些联系人并将它们添加到保存在数据库中的组中。

我创建了一个自定义列表视图-contactitem.xml-

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"


android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal">


 <TextView

    android:id="@+id/contactname"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_gravity="center_vertical"
    android:layout_weight="1"
    android:layout_marginLeft="20dp"
    android:ellipsize="end"        
   android:singleLine="true"
    android:clickable="true"/>

 <TextView
    android:id="@+id/contactnum"
    android:layout_width="wrap_content"
     android:textColor="@color/White"
     android:clickable="true"
     android:layout_gravity="center_vertical"
     android:layout_height="wrap_content"/>

  <Button
    android:id="@+id/add"
    android:layout_width="wrap_content"
    android:layout_height="35dp"
    android:text="@string/add_contacts"
    android:layout_gravity="center_vertical"
    android:layout_marginLeft="10dp"
    android:layout_marginRight="10dp"
    android:focusable="false"
    android:focusableInTouchMode="false"/>

</LinearLayout>

我有一个 SelectContact 类用于从通讯录中获取联系人-

public class SelectContacts extends Activity implementsOnItemClickListener {

    private List<Contact> list = new ArrayList<Contact>();
    private ListView contact_list;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.selectcontacts);
        contact_list=(ListView)findViewById(R.id.contactsListView);
        ContentResolver cr = getContentResolver();
        Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
        cur.moveToFirst();
        if (cur.getCount() > 0) {
            while (cur.moveToNext()) {
                String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
                String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
                if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0) {
                    Cursor pCur = cr.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?", new String[]{id}, null);
                    pCur.moveToFirst();
                    while (pCur.moveToNext()) {
                        String number=pCur.getString(cur.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                        Contact c=new Contact();
                        c.setContactName(name);
                        c.setContactNum(number);
                        list.add(c);
                    }
                    pCur.close();
                }
                ContactAdapter contactAdapter=new ContactAdapter(this, R.layout.contactitem, list);
                contact_list.setAdapter(contactAdapter);
            }
        }
    }

    @Override
    public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
        // TODO Auto-generated method stub
    }
}

并实现了一个自定义适配器-ContactAdapter-

public class ContactAdapter extends ArrayAdapter<Contact>{

    List<Contact> items;
    LayoutInflater mInflater ; 
    Context context;
    int layoutResourceId; 

    public ContactAdapter(Context context, int layoutResourceId, List<Contact> items) {
        super(context, layoutResourceId, items);
        this.layoutResourceId=layoutResourceId;
        this.items = items;
        this.context=context;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        ViewHolder holder = new ViewHolder();
        if(row==null){
            mInflater = ((Activity)context).getLayoutInflater();
            row = mInflater.inflate(layoutResourceId, parent, false);
            holder.name = (TextView) row.findViewById(R.id.contactname);
            holder.number = (TextView) row.findViewById(R.id.contactnum);
            holder.add=(Button)row.findViewById(R.id.add);
            row.setTag(holder);
        }else{
            holder=(ViewHolder)row.getTag();
        }

        String name=items.get(position).getContactName();
        String number=items.get(position).getContactNum();
        holder.name.setText(name);
        holder.number.setText(number);
        holder.add.setText("Add");
        return row;
    }

    static class ViewHolder{
        TextView name;
        TextView number;
        Button add;
    }
}

这里的Contact是一个简单的POJO-

public class Contact {
    private String contactName;
    private String contactNum;

    public String getContactName() {
        return contactName;
    }
    public void setContactName(String contactName) {
        this.contactName = contactName;
    }

    public String getContactNum() {
        return contactNum;
    }
    public void setContactNum(String contactNum) {
        this.contactNum = contactName;
    }

}

我是安卓新手..

在这里，当我启动 SelectContact 活动时，它无法在 UI 上显示联系人。请帮帮我...

谢谢

Answer 1

我会坚持你使用List<Contact> list = new ArrayList<Contact>(); 而不是ArrayList<HashMap<String, Contact>> list= new ArrayList<HashMap<String, Contact>>();

您只需要获取联系人详细信息并将值设置为Contact 类并添加到ArrayList 对象。然后只需将列表对象传递给 ArrayAdapter 类并使用它。这是最简单的方法，在这种情况下使用HashMap 会使其变得有点复杂。