Question

我试图将数据调用到Listview，但应用程序终止。

数据库helper.java中的

我有这个功能：

public List<Presentation> getAllPresentations() {
    List<Presentation> presentations = new ArrayList<Presentation>();
    String selectQuery = "SELECT * FROM " + TABLE_PRESENTATION;
    Log.e(LOG, selectQuery);
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    if (c.moveToFirst()) {
        do {
            Presentation p = new Presentation();
            p.setId(c.getInt((c.getColumnIndex(KEY_ID))));
            p.setTitle(c.getString(c.getColumnIndex(KEY_TITLE)));
            p.setDescription(c.getString(c.getColumnIndex(KEY_DESCRIPTION)));
            p.setPatient_name(c.getString(c.getColumnIndex(KEY_PATIENT_NAME)));

            presentations.add(p);
        } while (c.moveToNext());
    }
    return presentations;
}

在xml文件（view_presentation）中我有一个带有id列表的ListView

在view_presentations.java中的

我有这段代码：

public class view_presentations extends Activity
{
    // Database Helper
    DatabaseHelper db;

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

        if (db.getPresentationsCount() != 0)
        {
            List<Presentation> list = db.getAllPresentations();
            ListView l = (ListView)findViewById(R.id.list);
            l.setAdapter(new ArrayAdapter<Presentation>(this, R.layout.view_presentation, list));

        }
    }
}

此时

应显示包含所有演示文稿的列表，但应用程序将终止。有什么帮助吗？

Android应用程序在向ListView调用数据时终止

0 个答案: