单击由 AsyncTask 生成的列表视图项后，如何打开对话框？

Question

public class MainActivity extends Activity {

  ListView list;
    LinearLayout ll;
    Button loadBtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ll = (LinearLayout) findViewById(R.id.LinearLayout1);

    list = (ListView) findViewById(R.id.listView1);

    loadBtn = (Button) findViewById(R.id.button1);
    loadBtn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
           LoadContacts lc=new LoadContacts();
           if(lc.execute()!=null)
           {
            Toast toast=Toast.makeText(MainActivity.this, "hello", Toast.LENGTH_LONG);
            toast.show();
           }

        }
    });

}

    class LoadContacts extends AsyncTask<Void, Void, ArrayList<String>>
    {

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

             pd = ProgressDialog.show(MainActivity.this, "Loading Contacts",
                     "Please Wait");
         }
         protected ArrayList<String> doInBackground(Void... params) {
             // TODO Auto-generated method stub
             ArrayList<String> contacts = new ArrayList<String>();

             Cursor c = getContentResolver().query(
                     ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,
                     null, null, null);
             while (c.moveToNext()) {

                 String contactName = c
                         .getString(c
                                 .getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
                 String phNumber = c
                         .getString(c
                                 .getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));

                 contacts.add(contactName + ":" + phNumber);

             }
             c.close();

             return contacts;
         }
         @Override
         protected void onPostExecute(ArrayList<String> contacts) {
             // TODO Auto-generated method stub
             super.onPostExecute(contacts);

             pd.cancel();

             ll.removeView(loadBtn);

             ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                     getApplicationContext(), R.layout.text, contacts);

             list.setAdapter(adapter);

             list.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    AlertDialog.Builder adb=new AlertDialog.Builder(MainActivity.this);
                    adb.setTitle("call & message");
                    adb.setPositiveButton("call", new DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            // TODO Auto-generated method stub
                            //write here call coding

                        }
                    });

                    adb.setNegativeButton("message", new DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            // TODO Auto-generated method stub
                            //write here message coding
                        }
                    });     
                    }               

            });               
 }
}
}

这是我的MainActivity.java 文件。当我删除对话代码时，它可以正常工作并加载联系人，但对话代码无法正常工作，请任何人帮助我。

Answer 1

只需使用 setOnItemClickListener 而不是 onClickListener ：

            list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                // TODO Auto-generated method stub
                AlertDialog.Builder adb=new AlertDialog.Builder(MainActivity.this);
                adb.setTitle("call & message");
                adb.setPositiveButton("call", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        //write here call coding

                    }
                });

                adb.setNegativeButton("message", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        //write here message coding
                    }
                });
            }
        });

Answer 2

之后调用您的网络服务

list = (ListView) findViewById(R.id.listView1);

在onCreate()中调用webservice后编写listview clicklistener。

因此步骤将是，

• list = (ListView) findViewById(R.id.listView1)
• 新的 LoadContacts().execute()
• list.setOnItemClickListener()

Answer 3

您需要使用list.setOnItemClickListener 来点击列表中的特定项目。

list.setOnClickListener 将允许您单击列表视图，是的，但它将整个列表视为一个巨大的按钮。

您可以将整个侦听器代码块从 AsyncTask 移出并移到 onCreate 中，因为 AsyncTask 只需要获取联系人列表并更新列表视图适配器，仅此而已。