Android - 使用预加载的数据库填充Listview

时间:2012-01-09 16:40:56

标签: android database listview

我想使用我使用SQLite数据库浏览器创建的预加载数据库填充listview。但是,我一直强行关闭。对于DatabaseHelper类,我在http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/

上完全遵循了教程

这是我显示listView的代码:

public class POITab extends ListActivity {
private SQLiteDatabase newDb;
protected Cursor cursor;
protected ListAdapter adapter;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    openDatabase();     
}


private void openDatabase() {
    POIHelper dbHelper = new POIHelper(this.getApplicationContext());
    newDb = dbHelper.getWritableDatabase();
    cursor = newDb.rawQuery("SELECT _id, Name FROM POI", null);
    adapter = new SimpleCursorAdapter(this, R.layout.listitem, cursor, new String[] {"Name"}, new int[] {R.id.name});
    setListAdapter(adapter);
}

@Override
public void onListItemClick(ListView parent, View view, int position, long id) {
      Toast.makeText(getApplicationContext(), ((TextView) view).getText(),
              Toast.LENGTH_SHORT).show();
}

更新:我不确定,但我猜问题就在于行

cursor = newDb.rawQuery("SELECT _id, Name FROM POI", null);

这是我的databaseHelper类的代码:

public class POIHelper extends SQLiteOpenHelper {

private static String DB_PATH = "/data/data/com.test.mysgapp/databases/";
private static String DB_NAME = "MySgAppdb";
private SQLiteDatabase myDatabase;
private final Context myContext;

public POIHelper(Context context) {
    super(context, DB_NAME, null, 1);
    this.myContext = context;
}

public void createDatabase() throws IOException {
    boolean dbExist = checkDatabase();
    if(dbExist) {

    } else {
        this.getReadableDatabase();
        try {
            copyDatabase();
        } catch (IOException e) {
            throw new Error("Error copying database");
        }
    }
}

private boolean checkDatabase() {
    SQLiteDatabase checkDb = null;

    try {
        String myPath = DB_PATH + DB_NAME;
        checkDb = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
    } catch (SQLiteException e) {
    }

    if(checkDb != null) {
        checkDb.close();
    }
    return checkDb != null ? true : false;
}

private void copyDatabase() throws IOException{
    InputStream input = myContext.getAssets().open(DB_NAME);
    String outFileName = DB_PATH + DB_NAME;
    OutputStream output = new FileOutputStream(outFileName);

    byte[] buffer  = new byte[1024];
    int length;
    while ((length = input.read(buffer))>0) {
        output.write(buffer, 0, length);
    }
    output.flush();
    output.close();
    input.close();
}

public void openDatabase() throws IOException {
    String path = DB_PATH + DB_NAME;
    myDatabase = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READONLY);
}

@Override
public synchronized void close() {
    if (myDatabase != null)
        myDatabase.close();

    super.close();
}

@Override
public void onCreate(SQLiteDatabase db) {
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}

}

错误日志:

  

01-10 16:11:52.332:ERROR / AndroidRuntime(1311):致命异常:主要   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):   java.lang.RuntimeException:无法启动活动   ComponentInfo {com.test.mysgapp / com.test.mysgapp.POITab}:   android.database.sqlite.SQLiteException:没有这样的表:Places :,   编译时:SELECT _id,Name FROM Places 01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.widget.TabHost $ IntentContentStrategy.getContentView(TabHost.java:651)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.widget.TabHost.setCurrentTab(TabHost.java:323)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   android.widget.TabHost $ 2.onTabSelectionChanged(TabHost.java:129)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   android.widget.TabWidget $ TabClickListener.onClick(TabWidget.java:453)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.view.View.performClick(View.java:2408)01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   android.view.View $ PerformClick.run(View.java:8816)01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   android.os.Handler.handleCallback(Handler.java:587)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   android.os.Handler.dispatchMessage(Handler.java:92)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   android.os.Looper.loop(Looper.java:123)01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   android.app.ActivityThread.main(ActivityThread.java:4627)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   java.lang.reflect.Method.invokeNative(Native Method)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   java.lang.reflect.Method.invoke(Method.java:521)01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:868)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   dalvik.system.NativeStart.main(Native Method)01-10 16:11:52.332:   ERROR / AndroidRuntime(1311):引起:   android.database.sqlite.SQLiteException:没有这样的表:Places :,   编译时:SELECT _id,Name FROM Places 01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   android.database.sqlite.SQLiteCompiledSql.native_compile(母语   方法)01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.database.sqlite.SQLiteCompiledSql.compile(SQLiteCompiledSql.java:91)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.database.sqlite.SQLiteCompiledSql。(SQLiteCompiledSql.java:64)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.database.sqlite.SQLiteProgram。(SQLiteProgram.java:80)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.database.sqlite.SQLiteQuery。(SQLiteQuery.java:46)01-10   16:11:52.332:ERROR / AndroidRuntime(1311):at   android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:42)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1345)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1315)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   com.test.mysgapp.POITab.openDb(POITab.java:42)01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   com.test.mysgapp.POITab.onCreate(POITab.java:36)01-10 16:11:52.332:   错误/ AndroidRuntime(1311):at   android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):at   android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)   01-10 16:11:52.332:ERROR / AndroidRuntime(1311):... 18更多01-10   16:11:52.392:WARN / ActivityManager(41):强制完成活动   com.test.mysgapp / .MySgApp

2 个答案:

答案 0 :(得分:0)

我猜测但是不应该将setListAdapter(适配器)添加到列表中? 像myList.setListAdapter(adapter);

答案 1 :(得分:0)

感谢观看和帮助。我设法解决了这个问题。它位于数据库中。数据库文件有问题。我创建了一个新的,现在一切正常。