從sqlite中獲取數據並在gridview中顯示

Question

我在SQLite數據庫中有150條記錄。我想在網格視圖中顯示數據庫中的一行。用戶將在編輯文本中輸入代碼，並且我想根據數據庫中的代碼選擇一條記錄並顯示在網格視圖中。我用下面的方法從數據庫中獲取數據，但我不知道如何在網格視圖中插入值。

從SQLite的獲取檢索數據

方法：

public String[][] SelectDocData(String drcode) { 
// TODO Auto-generated method stub 
try { 

    String arrData[][] = null; 
    SQLiteDatabase db; 
    db = this.getReadableDatabase(); // Read Data 
    String strSQL = "select * from table = drcode" ; 
    Cursor cursor = db.rawQuery(strSQL, null); 
    if(cursor != null) 
    { 

    if (cursor.moveToFirst()) { 
    arrData = new String[cursor.getCount()][cursor.getColumnCount()]; 

int i= 0; 
do {    
arrData[i][0] = cursor.getString(0); 
arrData[i][1] = cursor.getString(1); 
arrData[i][2] = cursor.getString(2); 
i++; 

} while (cursor.moveToNext());      
}} 

cursor.close(); 
return arrData; 

} catch (Exception e) { 

return null; 
} 
} 

Answer 1

爲GridView設置卡就像ListView適配器。我想在這裏展示一個例子。

這是Gridview（activity_main.xml中）XML佈局：爲GridView

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:background="#ff00ff" 
android:orientation="vertical" > 

<TextView 
    android:id="@+id/tv_emp_id" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="ID" /> 

<TextView 
    android:id="@+id/tv_emp_name" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="name" /> 

<TextView 
    android:id="@+id/tv_emp_email" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Email" /> 

<TextView 
    android:id="@+id/tv_emp_address" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="Address" /> 

</LinearLayout> 

項

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
tools:context="com.example.griddemo.MainActivity" > 

<EditText 
    android:id="@+id/et_empcode" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="@string/hello_world" /> 

<GridView 
    android:id="@+id/gv_emp" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:numColumns="3" 
    android:horizontalSpacing="4dp" 
    android:verticalSpacing="4dp" 
    android:layout_below="@+id/et_empcode" > 
</GridView> 

</RelativeLayout> 

這是另一種佈局文件（layout_grid_item.xml）這是適配器類（MyAdapter.java）

public class MyAdapter extends BaseAdapter { 
Context context; 
ArrayList<Employee> empList; 
private static LayoutInflater inflater = null; 

public MyAdapter(Context context, ArrayList<Employee> empList) { 
    this.context = context; 
    this.empList = empList; 
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
} 

@Override 
public int getCount() { 
    // TODO Auto-generated method stub 
    return empList.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 position; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
    // TODO Auto-generated method stub 
    if (convertView == null) 
     convertView = inflater.inflate(R.layout.layout_grid_item, null); 

    TextView codeTextView = (TextView) convertView.findViewById(R.id.tv_emp_id); 
    TextView nameTextView = (TextView) convertView.findViewById(R.id.tv_emp_name); 
    TextView emailTextView = (TextView) convertView.findViewById(R.id.tv_emp_email); 
    TextView addressTextView = (TextView) convertView.findViewById(R.id.tv_emp_address); 

    Employee e = new Employee(); 
    e = empList.get(position); 
    codeTextView.setText("Code: " + String.valueOf(e.getCode())); 
    nameTextView.setText("Name: " + e.getName()); 
    emailTextView.setText("Email: " + e.getEmail()); 
    addressTextView.setText("Address: " + e.getAddress()); 
    return convertView; 
} 

} 

這是模型類（Employee.java）

package com.example.griddemo; 

public class Employee { 

int code; 
String name, email, address; 

/* Setters */ 
public void setCode(int code) { 
    this.code = code; 
} 

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

public void setEmail(String email) { 
    this.email = email; 
} 

public void setAddress(String address) { 
    this.address = address; 
} 

/* Getters */ 
public int getCode() { 
    return this.code; 
} 

public String getName() { 
    return this.name; 
} 

public String getEmail() { 
    return this.email; 
} 

public String getAddress() { 
    return this.address; 
} 
} 

這是用於處理數據庫操作（DatabaseHelper.java）

public class DatabaseHelper extends SQLiteOpenHelper { 

private String TAG = this.getClass().getSimpleName(); 

private static final String DATABASE_NAME = "emp_db"; 
private static final int DATABASE_VERSION = 1; 

// TABLE NAMES 
private static final String TABLE_EMP = "employee"; 

/* Keys for Table Employee */ 
private static final String KEY_CODE = "code"; 
private static final String KEY_NAME = "name"; 
private static final String KEY_EMAIL = "email"; 
private static final String KEY_ADDRESS = "address"; 

String CREATE_TABLE_CALL = "CREATE TABLE " + TABLE_EMP + "(" + KEY_CODE + " INTEGER," + KEY_NAME + " TEXT," + KEY_EMAIL + " TEXT," + KEY_ADDRESS 
     + ")"; 

public DatabaseHelper(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 
    Log.v(TAG, "CREATE TABLE CALL: " + CREATE_TABLE_CALL); 
    db.execSQL(CREATE_TABLE_CALL); 

} 

@Override 
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    // TODO Auto-generated method stub 
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_EMP); 
    onCreate(db); 
} 

/* Method to create a Employee */ 
public long createEmployee(Employee emp) { 
    long c; 

    SQLiteDatabase database = getWritableDatabase(); 
    ContentValues values = new ContentValues(); 
    values.put(KEY_CODE, emp.getCode()); 
    values.put(KEY_NAME, emp.getName()); 
    values.put(KEY_EMAIL, emp.getEmail()); 
    values.put(KEY_ADDRESS, emp.getAddress()); 

    c = database.insert(TABLE_EMP, null, values); 
    database.close(); 
    return c; 

} 

/* Method for fetching record from Database */ 
public ArrayList<Employee> getAllEmployee() { 
    String query = "SELECT * FROM " + TABLE_EMP; 
    ArrayList<Employee> employees = new ArrayList<Employee>(); 
    SQLiteDatabase database = getReadableDatabase(); 
    Cursor c = database.rawQuery(query, null); 
    if (c != null) { 
     while (c.moveToNext()) { 
      int code = c.getInt(c.getColumnIndex(KEY_CODE)); 
      String name = c.getString(c.getColumnIndex(KEY_NAME)); 
      String email = c.getString(c.getColumnIndex(KEY_EMAIL)); 
      String address = c.getString(c.getColumnIndex(KEY_ADDRESS)); 

      Employee emp = new Employee(); 
      emp.setCode(code); 
      emp.setName(name); 
      emp.setEmail(email); 
      emp.setAddress(address); 

      Log.v("DBHelper: ", "Name: " + name); 
      Log.v("DBHelper: ", "Code: " + code); 
      Log.v("DBHelper: ", "Email: " + email); 
      Log.v("DBHelper: ", "Address: " + address); 

      employees.add(emp); 
     } 
    } 

    return employees; 

} 
/* This method is used to get a single record from Database. 
    I have given an example, you have to do something like this. */ 

public Employee getEmployeeByCode(int code) 
{ 
    String query = "SELECT * FROM " + TABLE_EMP+ " WHERE "+ KEY_CODE + " = " +code; 
    Employee emp = new Employee(); 
    SQLiteDatabase database = getReadableDatabase(); 
    Cursor c = database.rawQuery(query, null); 

    if (c.getCount() > 0) { 

     c.moveToFirst(); 
     int code = c.getInt(c.getColumnIndex(KEY_CODE)); 
     String name = c.getString(c.getColumnIndex(KEY_NAME)); 
     String email = c.getString(c.getColumnIndex(KEY_EMAIL)); 
     String address = c.getString(c.getColumnIndex(KEY_ADDRESS)); 

     emp.setCode(code); 
     emp.setName(name); 
     emp.setEmail(email); 
     emp.setAddress(address); 

     Log.v("DBHelper: ", "Name: " + name); 
     Log.v("DBHelper: ", "Code: " + code); 
     Log.v("DBHelper: ", "Email: " + email); 
     Log.v("DBHelper: ", "Address: " + address); 


    } 
    return emp; 
} 

這是MainActivity.java類

public class MainActivity extends Activity { 

GridView gridView; 
ArrayList<Employee> employeeList; 
MyAdapter adapter; 

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

    gridView = (GridView) findViewById(R.id.gv_emp); 

    DatabaseHelper databaseHelper = new DatabaseHelper(MainActivity.this); 
    employeeList = new ArrayList<Employee>(); 

    employeeList = databaseHelper.getAllEmployee(); 
    adapter = new MyAdapter(MainActivity.this, employeeList); 
    gridView.setAdapter(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.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 
    if (id == R.id.action_settings) { 
     return true; 
    } 
    return super.onOptionsItemSelected(item); 
} 
}