Question

这是我完成的android studio项目编码：我知道我犯了多个错误，但在哪里？我是初学者

这是我的MainActivity类：

public class MainActivity extends AppCompatActivity{

public Elements titles;
public ArrayList<String> news_list = new ArrayList<>();
private CustomAdapter customAdapter;
private ListView lv;

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    lv = (ListView) findViewById(R.id.listView1);

   customAdapter = new CustomAdapter(this,news_list);
    new NewThread().execute();

}

    public class NewThread extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... arg) {

        Document doc;
        try {
            doc = Jsoup.connect("http://www.varzesh3.com").get();

            titles = doc.getElementsByClass("small-news-link");

            news_list.clear();
            for (Element news : titles) {
                news_list.add(news.text());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(String result) {

        lv.setAdapter(customAdapter);

    }
}

}

这是我的CustomAdapter类

public class CustomAdapter extends ArrayAdapter<String> {
List<String> listString;
Activity context;
Typeface typeFace;

public CustomAdapter(MainActivity mainActivity, List<String> listString) {
    super(mainActivity, R.layout.list_item,listString);
    this.context = mainActivity;
    this.listString = listString;
}



static class ViewHolder {
    public TextView textView;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View vi = convertView;
    if (vi == null) {
        LayoutInflater inflater = context.getLayoutInflater();
        vi = inflater.inflate(R.layout.list_item, null);
        ViewHolder viewHolder = new ViewHolder();
        viewHolder.textView = (TextView) vi.findViewById(R.id.news);
        vi.setTag(viewHolder);
    }
    ViewHolder holder = (ViewHolder) vi.getTag();
    typeFace = Typeface.createFromAsset(context.getAssets(), "fonts/IRANSans.ttf");
    holder.textView.setTypeface(typeFace);


    return vi;
}

}`

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >

<ListView
    android:id="@+id/listView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true" >
</ListView>

list_item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<TextView android:id="@+id/news"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="10dip"
    android:textSize="15dip"
    android:textStyle="bold"
    android:textColor="#000000"/>

Answer 1

在getView()的{{1}}方法中，您实际上从未显示任何文字。您为视图充气，创建CustomAdapter，设置ViewHolder ...但不显示任何文字。添加看起来像这样的代码：

Typeface

Answer 2

@Ben P.给你确切的答案，你没有从任何地方获得字符串，你刚刚膨胀list_row而没有得到任何acsual字符串。我建议你打开一个新类来处理带有外部类的Strings / Objetcs，然后用getter和setter说明 StringClass 并将ArrayList<StringClass> list;放在上面并将它连接到适配器之后只需在asynctask中使用它，更容易并使用OOP ... 干杯，祝你好运！

以下android CustomAdapter不起作用？

2 个答案: