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我想List adapter在此示例中使用自定义,以便我可以从中受益,getView() 然后获取列表视图中按钮的id

这样我就可以从数据库中检索(name_id)学生delete作为带有按钮的列表。

我想实现delete这样当用户点击它时,delete它会获取学生并将其从数据库中删除。 id

如何在此处将我的适配器更改为自定义列表适配器?

我的代码如下:

public class ManageSection extends ListActivity {

//ProgresogressDialog pDialog;

    private ProgressDialog pDialog;

    // Creating JSON Parser object

// Creating JSON Parser object
JSONParser jParser = new JSONParser(); //class
boolean x =true; 

ArrayList<HashMap<String, String>> studentList;

//url to get all products list
private static String url_all_student = "http://10.0.2.2/SmsPhp/view_student_info.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_student = "student";
private static final String TAG_StudentID = "StudentID";
private static final String TAG_StudentNo = "StudentNo";
private static final String TAG_FullName = "FullName";
// course JSONArray
JSONArray student = null;
private TextView mDateDisplay;
private int mYear;
private int mMonth;
private int mDay;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.manage_section);
        mDateDisplay = (TextView) findViewById(R.id.day);

        // add a click listener to the button

        // get the current date

        final Calendar c = Calendar.getInstance();
       mYear = c.get(Calendar.YEAR);
      mMonth = c.get(Calendar.MONTH);
        mDay = c.get(Calendar.DAY_OF_MONTH);
        mDateDisplay.setText(mDay+"-"+mMonth+"-"+mYear);


        studentList = new ArrayList<HashMap<String, String>>();



     // on seleting single course
        // launching Edit course Screen
         // on seleting single course
           // launching Edit course Screen




        new LoadAllstudent().execute();


    }


    /**
     * Background Async Task to Load all student by making HTTP Request
     * */
    class LoadAllstudent extends AsyncTask<String, String, String>
    {

        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(ManageSection.this);
            pDialog.setMessage("Loading student. Please wait...");
            pDialog.setIndeterminate(false);
                  }




        /**
         * getting All student from u r l
         * */
        @Override
        protected String doInBackground(String... args) {
            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            // getting JSON string from URL
            JSONObject json = jParser.makeHttpRequest(url_all_student, "GET", params);

            // Check your log cat for JSON response
            Log.d("All student : ", json.toString());

            try {
                // Checking for SUCCESS TAG
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1)
                {
                    // student found
                    // Getting Array of course
                    student = json.getJSONArray(TAG_student);

                    // looping through All courses
                    for (int i = 0; i < student.length(); i++)//course JSONArray
                    {
                        JSONObject c = student.getJSONObject(i); // read first

                        // Storing each json item in variable
                        String StudentID = c.getString(TAG_StudentID);
                        String StudentNo = c.getString(TAG_StudentNo);
                        String FullName = c.getString(TAG_FullName);

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

                        // adding each child node to HashMap key => value
                        map.put(TAG_StudentID, StudentID);
                        map.put(TAG_StudentNo, StudentNo);
                        map.put(TAG_FullName, FullName);

                        // adding HashList to ArrayList
                        studentList.add(map);
                    }
                } else {
                    x=false;

                }

            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }   

        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) { 
              // dismiss the dialog after getting all products 
              pDialog.dismiss(); 
              if (x==false)
                Toast.makeText(getBaseContext(),"no student" ,Toast.LENGTH_LONG).show();

              ListAdapter adapter = new SimpleAdapter( 
                      ManageSection.this,  studentList, 
                        R.layout.list_student, new String[] { TAG_StudentID, 
                              TAG_StudentNo,TAG_FullName}, 
                        new int[] { R.id.StudentID, R.id.StudentNo,R.id.FullName}); 
               setListAdapter(adapter); 

             // Updating parsed JSON data into ListView 

        } 


    }
}

请注意,如果有一种无需更改适配器的简单方法,我可以id为每个按钮制作一个。因为我听说我必须使用自定义列表适配器...

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2 回答 2

2

在此处使用 setListAdapter 为您的 ListActivity 使用自定义适配器:http: //developer.android.com/reference/android/app/ListActivity.html#setListAdapter (android.widget.ListAdapter )

然后,您将能够使用他们的 ID 等标记您的视图。

另一种没有自定义适配器的方法(更简单但不是首选)是将所有条目手动映射到列表中的位置。(因为你可以提供一个元素数组,你可以只使用位置来获取对象)。话虽如此,如果您只是想连接按钮,您可以让 onClick 记录元素的位置,然后当他们按下按钮时,您可以通过访问数组做出正确反应。

编辑:

在你的 onCreate 做:

getListView().setOnItemClickListener(new OnItemClickListener() {

public void onItemClick(AdapterView<?> parent, View view, final int pos, long id){
    selected_student=studentList.get(pos); //member of your activity.
});

然后在您的按钮 onClickListener 中,您只需执行 delete(selected_student);

于 2012-10-09T15:51:27.647 回答
1

您的列表需要一个点击监听器!

这是一个例子;

list.setOnItemClickListener(new OnItemClickListener() {

            public void onItemClick(AdapterView<?> arg0, View arg1, final int arg2, long arg3) {
                //get your information through array.get(arg0), find and delete in database, delete from your arraylist here, then call adapter.notifyDataSetChanged()


                });

这就是你所需要的!

于 2012-10-09T15:57:14.460 回答