如何将列表视图数据传递给另一个活动

Question

我已经成功获取json数据并制作了列表视图。 现在，我想发送一些附加功能，但是在发送附加功能之前，我试图展示一个测试用的面包。 但是，tost总是返回我提到的最后一个ID作为名称。 :(

（我是android dev的新手）

这是我的工作。 我做错了什么？ Tost完美地显示了位置，但是Tost显示了姓氏作为常量。 就像我单击第一个文件时显示的是“最后一个”字段，如果我单击中间文件时，它也显示了最后一个字段。

private String TAG = MainActivity.class.getSimpleName();
private ListView lv;
private ListView listView;


ArrayList<HashMap<String, String>> channelList;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.live_stream);

    channelList = new ArrayList<>();
    lv = (ListView) findViewById(R.id.list);
    lv.setOnItemClickListener(mMessageClickedHandler);

    new GetChannel().execute();
}





private class GetChannel extends AsyncTask<Void, Void, Void> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        Toast.makeText(LiveStreaming.this, "Streaming list is loading", Toast.LENGTH_LONG).show();
    }

    @Override
    protected Void doInBackground(Void... arg0) {
        HttpHandler sh = new HttpHandler();
        // Making a request to url and getting response
        String url = "http://ubpower.net/cricktv/tv.json";
        String jsonStr = sh.makeServiceCall(url);

        Log.e(TAG, "Response from url: " + jsonStr);
        if (jsonStr != null) {

            try {
                JSONObject jsonObj = new JSONObject(jsonStr);

                // Getting JSON Array node
                JSONArray channel = jsonObj.getJSONArray("channel");

                for (int i = 0; i < channel.length(); i++) {
                   JSONObject c = channel.getJSONObject(i);
                    String id = c.getString("id");
                    name = c.getString("name");
                    String quality = c.getString("quality");
                    address = c.getString("address");


                    // tmp hash map for single contact
                    HashMap<String, String> channel_hash = new HashMap<>();

                    // adding each child node to HashMap key => value
                    channel_hash.put("id", id);
                    channel_hash.put("name", name);
                    channel_hash.put("quality", quality);
                    channel_hash.put("address", address);



                    // adding contact to contact list
                    channelList.add(channel_hash);
                }



            } catch (final JSONException e) {
                Log.e(TAG, "Json parsing error: " + e.getMessage());
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(getApplicationContext(),
                                "Json parsing error: " + e.getMessage(),
                                Toast.LENGTH_LONG).show();
                    }
                });

            }

        } else {
            Log.e(TAG, "Couldn't get json from server.");
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(getApplicationContext(),
                            "Couldn't get json from server. Check LogCat for possible errors!",
                            Toast.LENGTH_LONG).show();
                }
            });
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        ListAdapter adapter = new SimpleAdapter(LiveStreaming.this, channelList,
                R.layout.stream_list, new String[]{ "name","quality","address"},
                new int[]{R.id.channel_title, R.id.channel_quality, R.id.channel_address});
        lv.setAdapter(adapter);



    }






}

// ********************用于单击列表项并传递数据的适配器

public AdapterView.OnItemClickListener mMessageClickedHandler = new AdapterView.OnItemClickListener() {
    public void onItemClick(AdapterView parent, View v, int position, long id) {

        Toast.makeText(LiveStreaming.this, "click item" + position + name , Toast.LENGTH_SHORT).show();
        Intent intent = new Intent(LiveStreaming.this, video_view.class);;
      // intent.putExtra("address", address);
        startActivity(intent);


    }

};

}

Answer 1

要获得点击，您需要向适配器添加一个项目Click监听器。 这是一种实现方法：

private OnItemClickListener mMessageClickedHandler = new OnItemClickListener() {
    public void onItemClick(AdapterView parent, View v, int position, long id) {
        // Do something in response to the click
    }
};

listView.setOnItemClickListener(mMessageClickedHandler);

要将数据放入新活动中，最简单的方法是将这些数据字段添加到用于创建新活动的Intent中。

Intent intent = new Intent(this, NewActivity.class);

intent.putExtra("SomeKey", value );

startActivity(intent);

Answer 2

//This may help
//Attach and Send date to another activity:

Bundle bundle = new Bundle();
bundle.putString("Name",Object); //This is for a String
i.setClass(CurrentClass.this, Class.class);
i.putExtras(bundle);
startActivity(i);

//Receive Data on second Activity:

Bundle bundle = null;
bundle = this.getIntent().getExtras();
String myString = bundle.getString("Name");//this is for String