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我想從父類(Main1Activity)中的子類(菜單)使用我的函數「列表」我怎麼能這樣做,以便我將使用該函數來調用我的列表?從父類中的子類調用函數?
而且我也不想讓功能在父類
public class Main1Activity extends Activity{
// i want to use list function here
}
public class menu extends Main1Activity {
public void list(View view) {
//Toast.makeText(getApplicationContext(), "clicked", 3000).show();
Cursor cursor2=mydb1.rawQuery("SELECT * FROM notes;", null);
if (cursor2.moveToFirst()) {
//Toast.makeText(getApplicationContext(), "Title's are:", 3000).show();
data.clear();
do {
data.add(cursor2.getString(cursor2.getColumnIndex("title")));
} while (cursor2.moveToNext());
ArrayAdapter <String> adapter=new ArrayAdapter<String>(menu.this,android.R.layout.simple_list_item_1,data);
lv.setAdapter(adapter);
}
else {
Toast.makeText(getApplicationContext(), "There are no notes to display ", 3000).show();
}
cursor2.close();
}
}
**「我不想在父類中做功能」** - 這是不能做到的。一個超類永遠不會知道子類。通過繼承,你的菜單類是一個Main1Activity類,但Main1Activity不是一個菜單類。我建議你更深入地研究OOP。 – Squonk