我想将数据库中的数据检索到我的 ListView 中，但无法这样做。我的对应activity_view_list.xml 布局的java 文件名是ViewList.java。在这种情况下，请帮助我。下面是我的代码
DBHelper.java
package com.example.shoppinglist;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DBHelper extends SQLiteOpenHelper
{
private static final String DATABASE_NAME = "ShoppingDatabase";
private static final int DATABASE_VERSION = 1;
private static final String DATBASE_CREATE = "CREATE TABLE ShoppingList(Id integer primary key autoincrement not null," +
"List_name varchar(255) default null,List_status varchar(255) default 'OPEN'," +
"date datetime)";
public DBHelper(Context context, String name, CursorFactory factory,
int version) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(DATBASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
Log.w(DBHelper.class.getName(),
"Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will delete the old data.");
db.execSQL("DROP TABLE IF EXISTS ShoppingList");
//Method is called during creation of new database
onCreate(db);
}
}
DBAdpater.java
package com.example.shoppinglist;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
public class DBAdapter
{
private Context ctxt;
private SQLiteDatabase db;
private DBHelper dbHelper;
public static final String KEY_ROWID = "Id";
public static final String KEY_NAME = "List_name";
public static final String KEY_STATUS = "List_status";
public static final String KEY_DATE = "date";
//public static final String KEY_TOTAL_ITEMS = "Total_items";
private static final String DATABASE_TABLE = "ShoppingList";
public DBAdapter(Context ctxt)
{
this.ctxt = ctxt;
}
//Open database
public DBAdapter open() throws SQLException
{
dbHelper = new DBHelper(ctxt, null, null, 0);
db = dbHelper.getWritableDatabase();
return this;
}
//Close database
public void close()
{
dbHelper.close();
}
//Create a new item
public long insertItem(String list_name , String list_status, String date)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, list_name );
initialValues.put(KEY_STATUS, list_status);
initialValues.put(KEY_DATE, date);
return db.insert(DATABASE_TABLE, null, initialValues);
}
//update a item
/*public boolean updateItem(long rowId, String list_name,
String list_status, String date)
{
ContentValues updateValues = new ContentValues();
updateValues.put(KEY_NAME, list_name);
updateValues.put(KEY_STATUS, list_status);
updateValues.put(KEY_DATE, date);
return db.update(DATABASE_TABLE, updateValues, KEY_ROWID + "=" + rowId,
null) > 0;
}*/
//delete a item
public boolean deleteItem(long rowId)
{
return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
//return cursor over the list of all items in the database
public Cursor fetchAllItems(){
return db.query(DATABASE_TABLE, new String[]{KEY_ROWID, KEY_NAME,
KEY_STATUS, KEY_DATE},
null, null, null, null, null);
}
//return a cursor positioned at the defined item
public Cursor fetchItem(long rowId) throws SQLException{
Cursor mCursor = db.query(true, DATABASE_TABLE,
new String[]{KEY_ROWID, KEY_NAME, KEY_STATUS,
KEY_DATE}, KEY_ROWID + "=" + rowId, null, null, null, null, null);
if(mCursor != null){
mCursor.moveToFirst();
}
return mCursor;
}
}
activity_view_list.xml
<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"
tools:context=".ViewList" >
<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
</ListView>
</RelativeLayout>
视图列表.java
package com.example.shoppinglist;
import android.os.Build;
import android.os.Bundle;
import android.annotation.TargetApi;
import android.app.ListActivity;
import android.database.Cursor;
import android.view.Menu;
import android.view.TextureView;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;
public class ViewList extends ListActivity {
private DBAdapter dbadpater;
protected ListAdapter adapter;
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_list);
ListView listview = (ListView)findViewById(R.id.listView1);
dbadpater = new DBAdapter(ViewList.this);
dbadpater.open();
Cursor values = dbadpater.fetchAllItems();
adapter = new SimpleCursorAdapter(this, R.layout.list_example, values, new String[] {"Id","List_name"}, new int [] {R.id.txtid,R.id.txtname});
setListAdapter(adapter);
listview.setOnItemClickListener(new OnItemClickListener() {
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), ((TextureView)view).getTextAlignment(),Toast.LENGTH_LONG).show();
}
});
dbadpater.close();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_view_list, menu);
return true;
}
}