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我要在 Android JSON Parsing Activity 之前创建一个 Main Screen Activity，他的内容是

main_screen.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:gravity="center_horizontal">

    <!--  Sample Dashboard screen with Two buttons -->
    <Button android:id="@+id/btnViewProducts"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="View Products"
        android:layout_marginTop="25dip"/>
</LinearLayout>

AndroidJSONParsingActivity.java

public class AndroidJSONParsingActivity extends ListActivity {


    // url to make request
    private static String url = "http://api.androidhive.info/contacts/";

    // JSON Node names
    private static final String TAG_CONTACTS = "contacts";
    private static final String TAG_ID = "id";
    private static final String TAG_NAME = "name";
    private static final String TAG_EMAIL = "email";
    private static final String TAG_ADDRESS = "address";

    // contacts JSONArray
    JSONArray contacts = null;




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

        // Hashmap for ListView
        ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();

        // Creating JSON Parser instance
        JSONParser jParser = new JSONParser();

        // getting JSON string from URL
        JSONObject json = jParser.getJSONFromUrl(url);

        try {
            // Getting Array of Contacts
            contacts = json.getJSONArray(TAG_CONTACTS);

            // looping through All Contacts
            for(int i = 0; i < contacts.length(); i++){
                JSONObject c = contacts.getJSONObject(i);

                // Storing each json item in variable
                String id = c.getString(TAG_ID);
                String name = c.getString(TAG_NAME);
                String email = c.getString(TAG_EMAIL);
                String address = c.getString(TAG_ADDRESS);

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

                // adding each child node to HashMap key => value
                map.put(TAG_ID, id);
                map.put(TAG_NAME, name);
                map.put(TAG_EMAIL, email);
                map.put(TAG_ADDRESS, address);

                // adding HashList to ArrayList
                contactList.add(map);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }


        /**
         * Updating parsed JSON data into ListView
         * */
        ListAdapter adapter = new SimpleAdapter(this, contactList,
                R.layout.list_item,
                new String[] { TAG_NAME, TAG_EMAIL, TAG_ADDRESS }, new int[] {
                        R.id.name, R.id.email, R.id.address });

        setListAdapter(adapter);

        // selecting single ListView item
        ListView lv = getListView();

        // Launching new screen on Selecting Single ListItem
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                // getting values from selected ListItem
                String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
                String email = ((TextView) view.findViewById(R.id.email)).getText().toString();
                String address = ((TextView) view.findViewById(R.id.address)).getText().toString();

                // Starting new intent
                Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
                in.putExtra(TAG_NAME, name);
                in.putExtra(TAG_EMAIL, email);
                in.putExtra(TAG_ADDRESS, address);
                startActivity(in);

            }
        });     

    }
}

我需要在 json 解析器数据之前创建一个 ProgressDialog 并在解析数据完成后关闭它

我是 Android 新手 谢谢你的进步

4

2 回答 2

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试试这个...使用 AsyncTask 并使用下面的代码。

private ProgressDialog progressDialog; // class variable

private void showProgressDialog(String title, String message)
{
        progressDialog = new ProgressDialog(this);

        progressDialog.setTitle(title); // set title 

        progressDialog.setMessage(message); // set message

        progressDialog.setCancelable(false);

        progressDialog.show();
}

onPreExecute()

 showProgressDialog("Please wait...", "Connecting to server for data");

onPostExecute()

  if(progressDialog != null && progressDialog.isShowing())
  {
     progressDialog.dismiss();
  }
于 2013-05-15T10:06:50.197 回答
0

使用 Async Task 下载 json 数据，

因此您可以在 preexecute 方法上启动进度 dilog 并在 Post execute 方法上停止它

于 2013-05-15T10:07:54.677 回答