如何在Android中将哈希映射数组从一个活动发送到另一个活动

Question

I have a list view in Main activity, I have fill some values in it by using Array Adapter

String[] arr = new String[]{"Android ListView Item 1", "Android ListView Item 2",
        "Simple List View In Android", "List View onClick Event","Android List View OnItemClickListener",
        "Open New Activity When ListView item Clicked", "List View onClick Source Code", "List View Array Adapter Item Click",
};

Now I want to set onclickListener to each item of the list. I am requesting an api which gives me jsonresponse and I want to iterate over jsonresponse and send required data to another activity when click item of the list.

I tried with following:

ArrayAdapter<String> arrayadapter = new ArrayAdapter<String>(this, 
R.layout.activity_main2, R.id.textview, arr);

    listview.setAdapter(arrayadapter);

    listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {
            String textToPass = "hello";
            if (position == 0) {
                Bundle passData = new Bundle();
                passData.putString("data",textToPass);
                Intent myIntent = new Intent(view.getContext(), Main2Activity.class);

                myIntent.putExtras(passData);
                startActivity(myIntent);
              }
         }
    });
}

private String jsonParse(){

    String url = "//testing/api.php"; //get json response locally
    RequestQueue requestQueue = Volley.newRequestQueue(this);
    JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(url, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            JSONArray jsonArray = null;
            try {
                jsonArray = response.getJSONArray("Item");

                for(int i=0; i<=jsonArray.length();i++){

                    HashMap<String,String> dict = new HashMap<String,String>();

                    JSONObject tv = jsonArray.getJSONObject(i);
                    String sid;

                    dict.put("cid", tv.getString("sid") );

                   // String cid = tv.getString("sid");
                    String categoryName =tv.getString("category_name");
                    String baseUrl = "//testing/";
                    String imageUrl = baseUrl + tv.getString("category_image");


                    //textView.append(cid + "," + categoryName + "," + imageUrl + "\n\n");

                }

            } catch (JSONException e) {
                e.printStackTrace();
            }
            assert jsonArray != null;
            Log.d("Main",jsonArray.toString());

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.d(error.getMessage(), "utf-8");
        }
    });



    requestQueue.add(jsonObjectRequest);

Please help

Answer 1

If I understood properly then I think you want to send HashMap dic to another activity. HashMap are serializable this means you can easily pass it in intent, moreover both key and value are string which are also serializable

intent.putExtra("dic.key", dic);

And in your next activity retrieve it with typecasting.. simple

HashMap<String, String> hashMap = (HashMap<String, String>) intent.getSerializableExtra("hashMap");

Answer 2

I have not test this yet, but give it a try:
At sender activity

HashMap<String, String> dict = new HashMap<>();

// Fill your data to dict 
...

Bundle data = new Bundle();

// Save hash map size
data.putInt("size", dict.size());

// Save each entry (String, String)
int i = 0;
for (Map.Entry<String, String> entry : dict.entrySet()) {
    String key = entry.getKey();
    String value = entry.getValue();
    data.putString("key" + i, key);
    data.putString("value" + i, value);
    ++i;
}

// Put data to intent starting receiver activity
...

At receiver activity

// Get bundle data from intent
Bundle data = getIntent().getExtras();

// Create a new map
HashMap<String, String> map = new HashMap<>();

// Get hash map size
int size = data.getInt("size");

// Get each entry from bundle then put to hash map
for (int i = 0; i < size; ++i){
    String key = data.getString("key" + i);
    String value = data.getString("value" + i);
    map.put(key, value);
}