Question

我要在单击后删除该行。它正在从数据库中删除行，但更改不会立即显示在屏幕上。关闭并重新打开该应用程序后，它会出现。
我已经使用notifyDataSetChanged（）。

MainActivity.java

@Override
protected void onStart() {
    super.onStart();
    display();
}

public void display(){
    final DbHelper mDbHelper = new DbHelper(this);
    SQLiteDatabase db = mDbHelper.getReadableDatabase();

    Cursor cursor = db.rawQuery(" SELECT * FROM "+  Contract.Entry.TABLE_NAME, null);

    ListView lv = (ListView)findViewById(R.id.tv);

    final nCursorAdapter nc = new nCursorAdapter(this, cursor);
    lv.setAdapter(nc);

    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            try {

            SQLiteDatabase db = mDbHelper.getWritableDatabase();
            db.delete(Contract.Entry.TABLE_NAME, Contract.Entry.COL_ID + " = ?",
                    new String[] { String.valueOf(id) });
            db.close();

            nc.notifyDataSetChanged();

            }catch (Exception e){
                Toast.makeText(getApplicationContext(),""+e, Toast.LENGTH_SHORT).show();
            }
        }
    });
    lv.invalidateViews();

}

nCursorAdapter.java

public class nCursorAdapter extends CursorAdapter {
public nCursorAdapter(Context context, Cursor c) {
    super(context, c, 0);
}

@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
    return LayoutInflater.from(context).inflate(R.layout.list, parent, false);
}

@Override
public void bindView(View view, Context context, Cursor cursor) {
    TextView first_name = (TextView)view.findViewById(R.id.namef);
    TextView last_name = (TextView)view.findViewById(R.id.namel);
    TextView ph_num = (TextView)view.findViewById(R.id.number);

    String fname = cursor.getString(cursor.getColumnIndex(Contract.Entry.COL_F_NAME));
    String lname = cursor.getString(cursor.getColumnIndex(Contract.Entry.COL_L_NAME));
    String phn = cursor.getString(cursor.getColumnIndex(Contract.Entry.COL_NUM));

    first_name.setText(fname);
    last_name.setText(lname);
    ph_num.setText(phn);
}

}

Answer 1

此方法将重新加载Activity，而不会出现闪烁或动画

private void refresh() {
    Intent intent = getIntent();
    overridePendingTransition(0, 0);
    intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
    finish();
    overridePendingTransition(0, 0);
    startActivity(intent);
}

因此，删除行后，请调用此方法。

在android中删除一行后如何显示更新的数据库？

1 个答案: