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Java 从Sqlite数据库填充Listview_Java_Android_Android Listview_Arraylist_Android Sqlite - Fatal编程技术网

Java 从Sqlite数据库填充Listview

Java 从Sqlite数据库填充Listview,java,android,android-listview,arraylist,android-sqlite,Java,Android,Android Listview,Arraylist,Android Sqlite,我试图弄清楚如何用sqlite数据库中的数据填充我的listview。实际上,我遵循了发布的教程 我的代码发布在下面: DatabaseHandler.java import java.util.ArrayList; import java.util.List; import android.content.ContentValues; import android.content.Context; import android.database.Cursor;

我试图弄清楚如何用sqlite数据库中的数据填充我的listview。实际上,我遵循了发布的教程

我的代码发布在下面:

DatabaseHandler.java

   import java.util.ArrayList;
   import java.util.List;
   import android.content.ContentValues;
   import android.content.Context;
   import android.database.Cursor;
   import android.database.sqlite.SQLiteDatabase;
   import android.database.sqlite.SQLiteOpenHelper;

      public class DatabaseHandler 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 DatabaseHandler(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(Contact contact) {
    SQLiteDatabase db = this.getWritableDatabase();

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

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

// Getting single contact
Contact 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();

    Contact contact = new Contact(Integer.parseInt(cursor.getString(0)),
            cursor.getString(1), cursor.getString(2));
    // return contact
    return contact;
}

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

    // return contact list
    return contactList;
}

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

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

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

// Deleting single contact
public void deleteContact(Contact 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();
      }

    }
Mainactivity.java

            import java.util.List;

     import android.app.Activity;
     import android.os.Bundle;
    import android.util.Log;
import android.widget.TextView;

   public class AndroidSQLiteTutorialActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
     Listview list =(Listview) findviewbyid(R.id.list);
    DatabaseHandler db = new DatabaseHandler(this);

    /**
     * CRUD Operations
     * */
    // Inserting Contacts
    Log.d("Insert: ", "Inserting .."); 
    db.addContact(new Contact("Ravi", "9100000000"));        
    db.addContact(new Contact("Srinivas", "9199999999"));
    db.addContact(new Contact("Tommy", "9522222222"));
    db.addContact(new Contact("Karthik", "9533333333"));

    // Reading all contacts
    Log.d("Reading: ", "Reading all contacts.."); 
    List<Contact> contacts = db.getAllContacts();       

    for (Contact cn : contacts) {
        String log = "" + cn.getName() +"";
            // Writing Contacts to log
    Log.d("Name: ", log);
   }
   }
  }

我做错了什么?

请先告诉我发生了什么不正确的事情。@tilmahauser我没有说任何不正确的事情。我只是问如何在代码中使用列表数组来填充我的listview。这就是全部。查看此链接:我在那里编写的问题和答案有代码片段来说明如何执行此操作。如果你没有说任何错误,那么问题是关于什么的?Donnie,你应该在问题文本中澄清你可以编辑你的问题是什么,那么,什么东西不能按您想要的方式工作,或者您必须解决什么问题,例如listview是空的或其他什么。