Question

我是android编码的新手，需要我的项目帮助：

我有一个函数，可以从mainActivity的OnResume调用。该函数从数据库中重新加载数据，并将其显示在列表视图中。现在，当我转到第二个Activity并输入新数据时，将在调用secondActivity的onPause时保存数据。返回mainActivity后，我看不到对列表视图所做的更改，但是当我单击列表视图的同一项并在第二次返回时再次转到第二个Activity时，更改开始显示，并且代码可以正常工作。第一次尝试功能不起作用的可能原因是什么？

注意：我还从主要Activity的onCreate调用了函数

编辑1：

调用函数

  public void fill_list() {

    cursor = db.rawQuery("SELECT * FROM " + GameEntry.TABLE + " WHERE " + GameEntry.G_DIFF + " = " + diff, null);
    yesitis = cursor.moveToFirst();
    if (yesitis)
        count = cursor.getCount();
    //int count=cursor.getCount();
    listv = (ListView) findViewById(R.id.listview1);
    listv.setAdapter(null);
    arr.clear();
    for (int j = 0; j < 15; j++) {
        String data;
        int j2 = j + 1;

        data = String.valueOf(j2);
 cursor3 = db.rawQuery("SELECT * FROM " + GameEntry.TABLE + " WHERE " + GameEntry.G_DIFF + " = " + diff+" AND "+GameEntry.G_LEVEL+" = "+j, null);

        if (cursor3.moveToFirst()) {
            cursor3.moveToPosition(0);

            int showstate = cursor3.getColumnIndex(AppContract.GameEntry.G_STATE);
            String temp1 = cursor3.getString(showstate);
            if (temp1.equals("notStarted")) {

            } else {
                int showtime = cursor3.getColumnIndex(AppContract.GameEntry.time);
                String temp2 = cursor3.getString(showtime);
                data = data + " " + temp1 + " " + temp2;
            }


        }
        arr.add(data);

    }
    ArrayAdapter<String> arradapt = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, arr) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            TextView textView = (TextView) super.getView(position, convertView, parent);
            switch (diff) {
                case 1:
                    textView.setBackgroundColor(Color.parseColor("#83EEA4"));
                    break;
                case 2:
                    textView.setBackgroundColor(Color.parseColor("#00C5F6"));
                    break;
                case 3:
                    textView.setBackgroundColor(Color.parseColor("#FF416A"));
                    break;

            }


            textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 25);
            return textView;
        }
    };
    listv.setAdapter(arradapt);
    listv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> av, View view, int ii, long id) {
            level_select=ii;
            cursor2 = db.rawQuery("SELECT * FROM " + GameEntry.TABLE + " WHERE " + GameEntry.G_DIFF + " = " + diff + " AND " + GameEntry.G_LEVEL + " = " + ii, null);
            if (cursor2.moveToFirst()) {
                cursor2.moveToPosition(0);
                g_exist = "yes";
            } else {
                g_exist = "no";
            }
            Intent send = new Intent(ListActivity.this, GameActivity.class);
            send.putExtra("level", ii);
            send.putExtra("difficulty", diff);
            send.putExtra("exist", g_exist);
            startActivity(send);
        }
    });
}

onResume：

  @Override
protected void onResume() {

    super.onResume();
    Toast.makeText(getApplicationContext(), "onResumed called", Toast.LENGTH_LONG).show();
       fill_list();
}

mainActivity onCreate：

  @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_list);
    MobileAds.initialize(this,
            "ca-app-pub-6165188418561315~3404004371");
    mAdView = (AdView) findViewById(R.id.adView);
    AdRequest adRequest = new AdRequest.Builder().build();
    mAdView.loadAd(adRequest);


    diff = getIntent().getExtras().getInt("difficulty");
    mhelper = new appdbhelper(this);
    db = mhelper.getReadableDatabase();
      fill_list();

    Toast.makeText(getApplicationContext(), "sqlsize =" + String.valueOf(yesitis), Toast.LENGTH_SHORT).show();

}

第二次活动暂停（enterdata函数更新数据库的指定行）：

  @Override
protected void onPause() {

    super.onPause();
    //Toast.makeText(getApplicationContext(), "onPause called", Toast.LENGTH_LONG).show();
  timer.stop();

    enterdata();
}

预先感谢

尝试1sr时OnResume未显示期望的结果

0 个答案: