我正在处理类似应用程序的联系簿。我有一个数据库，我想在ListView中显示数据。任何人都可以告诉我如何实现这一目标吗？以下是我到目前为止所尝试的内容，
public class Contacts {
private int id;
private String name;
private String phone_number;
private String email;
public Contacts()
{
}
public Contacts(int id, String name, String phone_number, String email)
{
this.id = id;
this.name = name;
this.phone_number = phone_number;
this.email = email;
}
public Contacts(String name, String phone_number, String email)
{
this.name = name;
this.phone_number = phone_number;
this.email = email;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPhone_number() {
return phone_number;
}
public void setPhone_number(String phone_number) {
this.phone_number = phone_number;
}
public void setEmail(String email) {
this.email = email;
}
public String getEmail() {
return email;
}
}
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 2;
private static final String DATABASE_NAME = "ContactsManager";
private static final String TABLE_CONTACTS = "contacts";
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_PH_NO = "phone_number";
private static final String KEY_EMAIL = "email";
public DatabaseHandler(Context context) {
super( context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_PH_NO + " TEXT," + KEY_EMAIL + " TEXT" + ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);
onCreate(db);
}
public void insertContact(Contacts contacts)
{
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, contacts.getName()); // Contact Name
cv.put(KEY_PH_NO, contacts.getPhone_number()); // Contact Phone
cv.put(KEY_EMAIL, contacts.getEmail()); //Contact Email
// Inserting Row
db.insert(TABLE_CONTACTS, null, cv);
db.close();
}
// Getting All Contacts
public List<Contacts> getAllContacts()
{
List<Contacts> contactList = new ArrayList<Contacts>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst())
{
do {
Contacts contact = new Contacts();
//contact.setId(Integer.parseInt(cursor.getString(0)));
contact.setName(cursor.getString(1));
contact.setPhone_number(cursor.getString(2));
contact.setEmail(cursor.getString(3));
// Adding contact to list
contactList.add(contact);
}
while (cursor.moveToNext());
}
// return contact list
return contactList;
}
}
public class View_data extends ListActivity {
DatabaseHandler db = new DatabaseHandler(this);
Cursor c ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_data);
db.getWritableDatabase();
List<Contacts> values = db.getAllContacts();
ArrayAdapter<Contacts> adapter = new ArrayAdapter<Contacts>(this,
android.R.layout.simple_list_item_1, values);
setListAdapter(adapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.view_data, menu);
return true;
}
}
在View_data课程中，我尝试显示数据但无法执行此操作。
任何建议将受到高度赞赏。
答案 0 :(得分：3)
您必须将上下文，列表项布局和光标传递到自定义适配器.........
final CustomAdapter adapter = new CustomAdapter(MainActivity.this,
R.layout.listitem, cursor);
list.setAdapter(adapter);
然后就是如何实现CustomAdapter类，你必须覆盖你的bindView方法。这看起来很复杂，直到你研究它，然后尝试自己做。
public class CustomAdapter extends CursorAdapter {
// Cursor cursor;
Context context;
public CustomAdapter(Context context, int RId, Cursor cursor) {
super(context, cursor);
// this.cursor = cursor;
this.context = context;
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
TextView team1 = (TextView) view.findViewById(R.id.listitem_team1);
team1.setText(cursor.getString(10));
TextView team2 = (TextView) view.findViewById(R.id.listitem_team2);
team2.setText(cursor.getString(11));
TextView date = (TextView) view.findViewById(R.id.listitem_date);
date.setText(cursor.getString(3));
TextView city = (TextView) view.findViewById(R.id.listitem_city);
city.setText(cursor.getString(2));
TextView time = (TextView) view.findViewById(R.id.listitem_time);
time.setText(cursor.getString(4));
TextView ground = (TextView) view.findViewById(R.id.listitem_ground);
date.setText(cursor.getString(1));}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
LayoutInflater inflater = LayoutInflater.from(context);
View v = inflater.inflate(R.layout.listitem, parent, false);
return v;
}
}
您也可以参考此链接http://dj-android.blogspot.in/2012/10/android-show-data-from-sqlite-db-into.html
答案 1 :(得分：0)
您必须将数据传递给UserAdapter。代码
List<DataProvider> data = userDbHelper.getInformation(sqLiteDatabase);用于从SQL数据库中检索应用于变量数据的数据。试试这个方法。
List<DataProvider> data = userDbHelper.getInformation(sqLiteDatabase);
UsersAdapter adapter = new UsersAdapter(this, (ArrayList<DataProvider>) data);
list.setAdapter(adapter);
然后在下面给出了UserAdapter类的实现，它扩展了ArrayAdapter ..
public class UsersAdapter extends ArrayAdapter<DataProvider> {
private static class ViewHolder {
TextView id;
TextView name;
TextView number;
}
public UsersAdapter(Context context, ArrayList<DataProvider> users) {
super(context, R.layout.new_layout, users);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
// User user = getItem(position);
DataProvider dataProvider = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
ViewHolder viewHolder; // view lookup cache stored in tag
if (convertView == null) {
// If there's no view to re-use, inflate a brand new view for row
viewHolder = new ViewHolder();
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.new_layout, parent, false);
viewHolder.id = (TextView)convertView.findViewById(R.id.textId);
viewHolder.name = (TextView) convertView.findViewById(R.id.textname);
viewHolder.number = (TextView) convertView.findViewById(R.id.textnumber);
// Cache the viewHolder object inside the fresh view
convertView.setTag(viewHolder);
} else {
// View is being recycled, retrieve the viewHolder object from tag
viewHolder = (ViewHolder) convertView.getTag();
}
// Populate the data from the data object via the viewHolder object
// into the template view.
viewHolder.id.setText(dataProvider.getId());
viewHolder.name.setText(dataProvider.getName());
viewHolder.number.setText(dataProvider.getMob());
// Return the completed view to render on screen
return convertView;
}
}
上面的代码是UserAdapter，它扩展了ArrayAdapter。试试这个方法你就会得到解决方案。 您也可以参考此链接https://github.com/codepath/android_guides/wiki/using-an-arrayadapter-with-listview