Question

我试图用我的加载按钮的onclicklistener中的sqlite数据填充我的listview。

然而，我对我见过的例子感到有些困惑。这是我在 TotalResults.java 中的代码。

DatabaseManager db = new DatabaseManager(this);
String name;
int score;
TextView result;
TextView saved;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_total_results);

    result = (TextView) findViewById (R.id.textResult);
    saved = (TextView) findViewById (R.id.textLoad);
    Button save = (Button) findViewById (R.id.buttonSave);
    Button load = (Button) findViewById (R.id.buttonLoad);
    Button delete = (Button) findViewById (R.id.buttonDelete);
      Intent intent = getIntent();
      name = intent.getExtras().getString("name");
      score = intent.getExtras().getInt("score");

      result.setText("Name: "+name+" , Score: "+score );

      save.setOnClickListener(new OnClickListener(){

            public void onClick(View v) {

                db.addContact(new PlayerData(name,score));
                Log.d("Inserting: ", name);
                Log.d("Inserting: ", Integer.toString(score));

            } 
      });



      load.setOnClickListener(new OnClickListener(){

            public void onClick(View v) {

                List<PlayerData> contacts = db.getAllContacts();
                //check to ensure there are users

                setListAdapter(new ListAdapter(this,
                        android.R.layout.simple_list_item_1, contacts));
                if(contacts.size()==0) {
                    String text = "No players stored.";
                    Toast.makeText(TotalResults.this, text, Toast.LENGTH_SHORT).show();
                } else {
                    PlayerData player = contacts.get(0);
                    String showName = player.getName();
                    int showScore = player.getscore();
                    Log.d("Getting:", showName);
                    Log.d("Getting:", Integer.toString(showScore));
                    saved.setText("Player Name: "+showName+" Player Score: "+showScore);
                }
            } 
      });

          delete.setOnClickListener(new OnClickListener(){

                public void onClick(View v) {

                    List<PlayerData> contacts = db.getAllContacts();
                    //check to ensure there are users
                    if(contacts.size()==0) {
                        String text = "No players to delete.";
                        Toast.makeText(TotalResults.this, text, Toast.LENGTH_SHORT).show();
                    } else {
                        PlayerData player = contacts.get(0);
                        String showName = player.getName();
                        int showScore = player.getscore();
                        Log.d("Deleting:", showName);
                        Log.d("Deleting:", Integer.toString(showScore));
                        db.deleteContact(player);
                    }

                } 
          });

这是我的数据库代码。

public class DatabaseManager extends SQLiteOpenHelper {

// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;

// Database Name
private static final String DATABASE_NAME = "contactsManager";

// Contacts table name
private static final String TABLE_CONTACTS = "contacts";

// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_PH_NO = "phone_number";

public DatabaseManager(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
    String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
            + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
            + KEY_PH_NO + " TEXT" + ")";
    db.execSQL(CREATE_CONTACTS_TABLE);
}

// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // Drop older table if existed
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);

    // Create tables again
    onCreate(db);
}

/**
 * All CRUD(Create, Read, Update, Delete) Operations
 */

// Adding new contact
void addContact(PlayerData contact) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_NAME, contact.getName()); // Contact Name
    values.put(KEY_PH_NO, contact.getscore()); // Contact Phone

    // Inserting Row
    db.insert(TABLE_CONTACTS, null, values);
    db.close(); // Closing database connection
}

// Getting single contact
PlayerData getContact(int id) {
    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID,
            KEY_NAME, KEY_PH_NO }, KEY_ID + "=?",
            new String[] { String.valueOf(id) }, null, null, null, null);
    if (cursor != null)
        cursor.moveToFirst();

    PlayerData contact = new PlayerData(Integer.parseInt(cursor.getString(0)),
            cursor.getString(1), cursor.getInt(2));

    cursor.close();
    // return contact
    return contact;
}

// Getting All Contacts
public List<PlayerData> getAllContacts() {
    List<PlayerData> contactList = new ArrayList<PlayerData>();
    // 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 {
            PlayerData contact = new PlayerData();
            contact.setID(Integer.parseInt(cursor.getString(0)));
            contact.setName(cursor.getString(1));
            contact.setscore(cursor.getInt(2));
            // Adding contact to list
            contactList.add(contact);
        } while (cursor.moveToNext());
    }
    cursor.close();
    // return contact list
    return contactList;
}

// Updating single contact
public int updateContact(PlayerData contact) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_NAME, contact.getName());
    values.put(KEY_PH_NO, contact.getscore());

    // updating row
    return db.update(TABLE_CONTACTS, values, KEY_ID + " = ?",
            new String[] { String.valueOf(contact.getID()) });
}

// Deleting single contact
public void deleteContact(PlayerData contact) {
    SQLiteDatabase db = this.getWritableDatabase();
    db.delete(TABLE_CONTACTS, KEY_ID + " = ?",
            new String[] { String.valueOf(contact.getID()) });
    db.close();
}


// Getting contacts Count
public int getContactsCount() {
    String countQuery = "SELECT  * FROM " + TABLE_CONTACTS;
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(countQuery, null);
    cursor.close();

    // return count
    return cursor.getCount();
}

}

我在这个方法中遇到错误：

  load.setOnClickListener(new OnClickListener(){

                public void onClick(View v) {

                    List<PlayerData> contacts = db.getAllContacts();
                    //check to ensure there are users

                    setListAdapter(new ListAdapter(this,
                            android.R.layout.simple_list_item_1, contacts));
                    if(contacts.size()==0) {
                        String text = "No players stored.";
                        Toast.makeText(TotalResults.this, text, Toast.LENGTH_SHORT).show();
                    } else {
                        PlayerData player = contacts.get(0);
                        String showName = player.getName();
                        int showScore = player.getscore();
                        Log.d("Getting:", showName);
                        Log.d("Getting:", Integer.toString(showScore));
                        saved.setText("Player Name: "+showName+" Player Score: "+showScore);
                    }
                } 
          });

我得到一个错误说：无法实例化ListAdapter类型，ListAdapter无法解析为类型。

请帮忙。提前致谢。：）

Answer 1

使用CustomAdapter

public class Display extends Activity implements OnItemClickListener{

    DatabaseManager db;
    List<PlayerData> contacts;
    ArrayList<String> con= new ArrayList<String>();
    LayoutInflater mInflater;
    CheckBox cb;
    TextView tv1;
    CustomAdapter cus;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listview);
        ListView lv= (ListView) findViewById(R.id.lv);
        db = new DatabaseManager(this);

           contacts = db.getAllContacts();       
        cus = new CustomAdapter();
        lv.setAdapter(cus);
        lv.setOnItemClickListener(this); 
        lv.setItemsCanFocus(false);
        lv.setTextFilterEnabled(true);
        Button b= (Button) findViewById(R.id.button1);
        b.setOnClickListener(new OnClickListener()
        {

            @Override
            public void onClick(View v) {
                StringBuilder sb = new StringBuilder();
                for(int i = 0; i < contacts.size(); i++)

                {
                if(cus.mCheckStates.get(i)==true)
                {
                    sb.append(contacts.get(i).getPhoneNumber());
                    sb.append("\n");

                }                    
            }
                Toast.makeText(getApplicationContext(), sb,
                            Toast.LENGTH_LONG).show();
                Intent intent = new Intent(Display.this,SendMessage.class);
                if(con!=null)
                {
                intent.putStringArrayListExtra("list",con);
                startActivity(intent);
                }
            }
        });

    }
    public void onItemClick(AdapterView parent, View view, int
            position, long id) {
                cus.toggle(position);

            }
    class CustomAdapter extends BaseAdapter implements CompoundButton.OnCheckedChangeListener
    {
          private SparseBooleanArray mCheckStates;
        CustomAdapter()
        {
            mCheckStates = new SparseBooleanArray(contacts.size());
             mInflater = (LayoutInflater)Display.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return contacts.size();
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return position;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub

            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            View vi=convertView;
            if(convertView==null)
             vi = mInflater.inflate(R.layout.rowlayout, null); 
             TextView tv= (TextView) vi.findViewById(R.id.textView1);
             tv1= (TextView) vi.findViewById(R.id.textView2);
             cb = (CheckBox) vi.findViewById(R.id.checkBox1);
             tv.setText("Name :"+ contacts.get(position).getName());
             tv1.setText("Phone No :"+ contacts.get(position).getPhoneNumber());
             cb.setTag(position);
             cb.setChecked(mCheckStates.get(position, false));
             cb.setOnCheckedChangeListener(this);
            return vi;
        }
         public boolean isChecked(int position) {
                return mCheckStates.get(position, false);
            }

            public void setChecked(int position, boolean isChecked) {
                mCheckStates.put(position, isChecked);
                notifyDataSetChanged();
            }

            public void toggle(int position) {
                setChecked(position, !isChecked(position));
            }
        @Override
        public void onCheckedChanged(CompoundButton buttonView,
                boolean isChecked) {
            // TODO Auto-generated method stub
             mCheckStates.put((Integer) buttonView.getTag(), isChecked);    

        }

    }

}

listview.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/lv"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:layout_above="@+id/button1"/>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:text="Button" />

</RelativeLayout>

rowlayout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="15dp"
        android:layout_marginTop="34dp"
        android:text="TextView" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/checkBox1"
        android:layout_alignLeft="@+id/textView1"
        android:text="TextView" />

    <CheckBox
        android:id="@+id/checkBox1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/textView1"
        android:layout_marginRight="33dp"
        android:text="@string/choice" />

</RelativeLayout>

listview中的每一行都如下所示。您可以单击复选框以选择和取消选中。稍后您可以获取所选项目并执行所需操作。

选中复选框后，点击底部的按钮。

如何使用sqlite从我的数据库填充ListView

1 个答案: