Question

我从Web服务中获取JSON中的数据，然后将数据放入自定义ListView。

点击ListView项后，我会打开一个新的Activity。现在我点击此活动的“提交”按钮，我将返回相同的ListView，

当我回到ListView时，我想更改我之前点击的listitem的文字

我只是想再次调用活动listticket.java

现在数据是静态的。我使用过网络服务。

listticket.java

public class listticket extends Activity {

    static ListView listView;

    ArrayList<String> aryTicket = new ArrayList<String>();

    private String[] listArr = { "A", "B" };

    private String[] listStatus = { "Alert", "Alert" };
    private String[] listTicketid = { "1", "2" };

    ArrayList<String> ary_ticket_code = new ArrayList<String>();

    ArrayList<String> ary_address = new ArrayList<String>();
    ArrayList<String> ary_ticketid = new ArrayList<String>();

    public static ArrayList<String> ary_status = new ArrayList<String>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        setContentView(R.layout.listticket);

        listView = (ListView) findViewById(R.id.itemList);

        // filllistdata();

        listArr = new String[ary_ticket_code.size()];
        listArr = ary_ticket_code.toArray(listArr);

        listStatus = new String[ary_status.size()];
        listStatus = ary_status.toArray(listStatus);

        listTicketid = new String[ary_ticketid.size()];
        listTicketid = ary_ticketid.toArray(listTicketid);

        MyArrayAdapter adapter = new MyArrayAdapter(this, listArr);
        listView.setAdapter(adapter);

    }

    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();

        ary_status.set(0, "Work Done");
        ((MyArrayAdapter) listView.getAdapter()).notifyDataSetChanged();

    }

    public class MyArrayAdapter extends ArrayAdapter<String> {

        Activity context;
        String[] listArr;

        private TextView btnchkout;

        // private final integer[] image;

        public MyArrayAdapter(Activity context, String[] objects) {
            super(context, R.layout.ticket, objects);
            // TODO Auto-generated constructor stub
            this.context = context;
            listArr = objects;

        }

        @Override
        public View getView(final int position, View convertView,
                ViewGroup parent) {
            // TODO Auto-generated method stub

            LayoutInflater inflater = (LayoutInflater) getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
            View view = inflater.inflate(R.layout.ticket, null, true);

            TextView textView = (TextView) view.findViewById(R.id.txtTicketNo);
            textView.setText(listArr[position]);

            final TextView txtAlert = (TextView) view
                    .findViewById(R.id.txtAlert1);
            // Toast.makeText(getApplicationContext(), listStatus[position],
            // Toast.LENGTH_LONG).show();
            String statusCheck = listStatus[position].toString().trim();

            if (statusCheck.equals("Alert") == true) {
                txtAlert.setText(statusCheck);
                txtAlert.setTextColor(getResources().getColor(R.color.red));

            } else if (statusCheck.equals("In Progress") == true) {
                txtAlert.setText(statusCheck);
                txtAlert.setTextColor(getResources().getColor(R.color.view));

            } else if (statusCheck.equals("Work Complete Pending paperwork") == true) {
                txtAlert.setText("Work Done");
                txtAlert.setTextColor(getResources().getColor(R.color.green));

            } else {
                txtAlert.setText(statusCheck);
                // txtAlert.setTextColor(getResources().getColor(R.color.defaulttextcolor));
            }

            final TextView btntextView = (TextView) view
                    .findViewById(R.id.btnCheckin);

            if (statusCheck.equals("In Progress")) {
                Drawable d = getResources().getDrawable(R.drawable.btncheckin);
                btntextView.setBackgroundDrawable(d);
            }

            btnchkout = (TextView) view.findViewById(R.id.btnCheckout);

            btnchkout.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    Intent intent = new Intent(listticket.this,
                            ticket_detail.class);
                    startActivity(intent);

                }
            });

            return view;
        }
    }

}

点击ListItem时的另一个布局

ticketdetail.java

protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        setContentView(R.layout.ticket_detail);



        btnSubmit = (TextView) findViewById(R.id.btnSubmit);


        btnSubmit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                     new AsyncAction().execute(null,null,null);


                //onBackPressed();
            }
        });
    }

    private class AsyncAction extends AsyncTask<String, Void, String> 
    {
         public boolean status=false;
        private ProgressDialog pd;
        @Override
        protected String doInBackground(String... arg0) 
        {
            // TODO Auto-generated method stub
            try
              {

            } 
              catch (Exception e) 
              {
                // TODO: handle exception
            }

            return null;
        }

        @Override
        protected void onPostExecute(String result) 
        {

           pd.dismiss();  
           Intent intent = new Intent(ticket_detail.this,listticket.class);
           intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
           intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
           startActivity(intent);
           //finish();

        }

        protected void onPreExecute() 
        {
            // TODO Auto-generated method stub
            super.onPreExecute();
            pd = new ProgressDialog(ticket_detail.this);
            pd.setMessage("Please Wait ...");
            pd.setIndeterminate(true);
            pd.setCancelable(false);
            pd.show();
        }

    }

      @Override
       public boolean onKeyDown(int keyCode, KeyEvent event) {
           if (keyCode == KeyEvent.KEYCODE_BACK) {
               Intent a = new Intent(ticket_detail.this,listticket.class);
               a.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
               startActivity(a);
               finish();

               return true;
           }
           return super.onKeyDown(keyCode, event);
       }

Answer 1

全局生成适配器对象，并在onCreate内部初始化一次，并在onResume()内部通知您的适配器，如下所示：

Delcaration

MyArrayAdapter适配器;

onCreate

adapter = new MyArrayAdapter(this, listArr);
listView.setAdapter(adapter);

onResume()

adapter.notifyDataSetChanged（）;

Answer 2

尝试此操作，添加，清除和删除调用notifyDataSetChanged本身，每次刷新信息时都不必更改适配器，价格昂贵。

adapter.clear()

for (Object o : object)
  adapter.add(o)

notifyDataSetChanged不起作用

2 个答案: