如何在android中将数组列表转换为数组

Question

我想搜索城市。我从服务器数据库获取城市的名称，我在listview.i上的Android手机上获得这个城市名称也使用搜索过滤器。在此代码中，我已经将arraylist转换为array.It没有从arraylist转换为postexecute中的数组。我可以将arraylist转换为数组??? 这是我的代码，我收到此错误：android.widget.ArrayAdapter.createViewfromresources中的java.lang.nullpointerexception 提前谢谢你

protected void onPostExecute（String file_url）

{

        runOnUiThread(new Runnable()

         {

            public void run() 

            {

                for(int j=1;j<10;j++)

                {

                    ListView lv = getListView();

                    String[] namesArr = new String[weatherlist.size()];

                    namesArr[j]=weatherlist.get(j).get(TAG_STATION);

                    Log.d("weather",namesArr[j]);

                    adapter = new ArrayAdapter<String>(Search.this, R.layout.list_item1, R.id.station_name, namesArr);

                    // updating list view

                    lv.setAdapter(adapter);

                    inputSearch.addTextChangedListener(new TextWatcher() 

                    {

                    @Override

                    public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) 

                    {
                        // When user changed the Text

                    Search.this.adapter.getFilter().filter(cs);  

                    }

                });

           } 

Answer 1

试试这个;

protected void onPostExecute(String file_url)

{

pDialog.dismiss();

runOnUiThread(new Runnable() 

{

public void run() 

{

    String[] namesArr = new String[weatherlist.size()];

    for(int i = 0 ; i < weatherlist.size() < i++){
        namesArr[i] = weatherlist.get(i).get("yourstringkey");

    }

    adapter = new ArrayAdapter<String>(Search.this, R.layout.list_item1, R.id.station_name, namesArr);

    // updating list view

    lv.setAdapter(adapter);

    inputSearch.addTextChangedListener(new TextWatcher() 

        {
            @Override

              public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) 
                {

                    // When user changed the Text

                    Search.this.adapter.getFilter().filter(cs);  
                }

               });

            }   
    });

}
}
}