Android ScrollView似乎无法识别其直接子级

Question

I'm using a ScrollView to show all the products that users add to his shopping cart. I create a scroll view and, into it, i create a linear layout 'intern'. Then, i build every single row in loop. Here's the XML

<ScrollView
    android:id="@+id/scroll"
    android:layout_width="300dp"
    android:layout_height="230dp"
    android:layout_marginLeft="10dp" >

    <LinearLayout 
        android:id="@+id/intern"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"></LinearLayout>
</ScrollView>

Here's the Java code.

for(Carrello cns : carrello){

            LinearLayout prodotto = new LinearLayout(context);
            LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(/**/LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
            prodotto.setLayoutParams(lp);
            //Product name
            TextView nome_p = new TextView(context);
            nome_p.setWidth(dpToPx(115));
            nome_p.setTextColor(getResources().getColor(R.color.grey));
            nome_p.setText(cns.getNomeProdotto());  /**/
            //Counts
            TextView quantita = new TextView(context);
            quantita.setWidth(dpToPx(80));
            quantita.setGravity(Gravity.CENTER);
            quantita.setTextColor(getResources().getColor(R.color.grey));
            quantita.setTextAppearance(context, R.style.quantita);
            quantita.setText(cns.getQuantita());  
            //Price
            TextView prezzo = new TextView(context);
            prezzo.setWidth(dpToPx(70));
            prezzo.setPadding(dpToPx(5), 0, 0, 0);
            prezzo.setTextColor(getResources().getColor(R.color.grey));
            prezzo.setTextAppearance(context, R.style.prezzo);
            prezzo.setText("€"+cns.getCosto());
            //Cancella
            Button canc = new Button(context);
            LinearLayout.LayoutParams lp_btn = new LinearLayout.LayoutParams(/*LinearLayout.LayoutParams.WRAP_CONTENT*/40,40/*LinearLayout.LayoutParams.WRAP_CONTENT*/);
            lp_btn.setMargins(0, dpToPx(10), 0, 0);
            canc.setLayoutParams(lp_btn);
            canc.setBackground(getResources().getDrawable(R.drawable.btn_canc));
            canc.setId(Integer.parseInt(cns.getIDprodotto()));/**/
            Log.d("ID-CANC",String.valueOf(canc.getId()));
            //create the line
            prodotto.addView(nome_p);
            prodotto.addView(quantita);
            prodotto.addView(prezzo);
            prodotto.addView(canc);
            intern.addView(prodotto);
            i++;
}//end for

Then, add intern to the scroll view:

scroll.addView(intern);

But when i run the emulator, logCat says that "ScrollView can host only one direct child", and the app crashes.

Answer 1

Don't use scroll.addView(intern); ,

because you have already defined child in SCrollView in your layout.xml

Instead try as below.

LinearLayout intern = (LinearLayout) findViewById(R.id.intern);

then use your for loop to add views in intern

That,s it...

No need to call addview for scroll

Hope this helps

Answer 2

The ScrollView already has a child defined in the layout file. scroll.addView(intern); will cause error.

Just add scroll=(ScrollView) findViewById(R.id.intern) before the loop and remove scroll.addView(intern); .