Stringbuilder无法正常工作

Question

我有一个奇怪的问题.这是代码:

public class TaxiDetails extends Activity{

ArrayList<Bus> listBus = new ArrayList<Bus>();
ArrayList<Taxi> listTaxi = new ArrayList<Taxi>();
TextView detalji, title;
ImageView backBtn;
String strType;
StringBuilder builder = new StringBuilder();

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);  
    setContentView(R.layout.numbers_details);
    detalji = (TextView) findViewById(R.id.txtNumbDetails);
    title = (TextView) findViewById(R.id.txtTitleNumbers);
    detalji.setTypeface(Typeface.DEFAULT_BOLD);
    Typeface TF = Typeface.createFromAsset(getAssets(), "fonts/Roboto-Black.ttf");
    backBtn = (ImageView) findViewById(R.id.backBtn);
    title.setTypeface(TF);

    Intent in = getIntent();
    strType = in.getStringExtra("type");

    if  (strType.equals("TAXI")){
        listTaxi = (ArrayList<Taxi>) in.getSerializableExtra("TAXI");
        title.setText("Taxi");
    } else if (strType.equals("BUS")){
        listBus = (ArrayList<Bus>) in.getSerializableExtra("BUS");
        title.setText("BUS");
    }   

    if (listBus != null) {
        for (int i = 0; i < listBus.size(); i++) {
            builder = new StringBuilder();
            String naslov = listBus.get(i).getTitle();
            String opis = listBus.get(i).getDescription();
            builder.append(naslov);
            builder.append("\n");
            builder.append(Html.fromHtml(opis));
            builder.append("\n");
        }
    }

    if (listTaxi != null) {
        for (int i = 0; i < listTaxi.size(); i++) {
            builder = new StringBuilder();
            String naslov = listTaxi.get(i).getTitle();
            String opis = listTaxi.get(i).getDescription();
            builder.append(naslov);
            builder.append("\n");
            builder.append(Html.fromHtml(opis));
            builder.append("\n");
        }
    }

    detalji.setText(builder.toString().trim());
}
}

我从之前的活动中传递了一个数组.可以是Taxi或Bus对象的数组,具体取决于用户选择的对象.然而,对于出租车来说,这非常有效.对于Bus,它只显示数组的最后一个对象,即使调试器显示listBus包含2个对象.我使用相同的listBus iN谷歌地图活动,它在那里显示所有对象的位置,那么为什么它在这里不起作用？

Answer 1

您正在StringBuilder循环的每次迭代中创建一个新的.它甚至不应该工作Taxis,因为你在那里做同样的事情.

只需在for循环外移动以下语句:

builder = new StringBuilder();

或者,您最好删除赋值,因为您已在实例变量声明中初始化它.所以你在这里不需要它.