Question

我有一个listView，可以让用户跟踪某些内容并删除项目行。当我按下删除按钮时，它显示问题如下。我已检查并在网上找到解决方案，但我无法理解他们的解决方式，也许我的情况与他们不同。对这个问题有什么想法？

Logcat输出（错误）：

java.lang.ArrayIndexOutOfBoundsException: length=1; index=-1
  at java.util.ArrayList.get(ArrayList.java:306)
  at android.widget.ArrayAdapter.getItem(ArrayAdapter.java:337)
  at com.example.android.project.ThirdActivity$3$2
      .onClick(ThirdActivity.java:295)
  at com.android.internal.app.AlertController$ButtonHandler
      .handleMessage(AlertController.java:174)
  at android.os.Handler.dispatchMessage(Handler.java:99)
  at android.os.Looper.loop(Looper.java:156)
  at android.app.ActivityThread.main(ActivityThread.java:4987)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:511)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller
      .run(ZygoteInit.java:784)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
  at dalvik.system.NativeStart.main(Native Method)

ThirdActivity.java

 friend = new ArrayList<String>(Arrays.asList(result.split("[*]")));  

 public void onListItemClick(ListView parent, View v, final int position, long id){
        AlertDialog.Builder adb = new AlertDialog.Builder(ThirdActivity.this);
               adb.setItems(item, new DialogInterface.OnClickListener() {                   
               public void onClick(DialogInterface dialog, int which) {                                        
                   if(item[which].equals("Track Location")){
                       ...
                   }else{
                       AlertDialog.Builder adb=new AlertDialog.Builder(ThirdActivity.this);
                       adb.setTitle("Delete?");
                       adb.setMessage("Are you sure you want to delete " + (String) lv.getItemAtPosition(position));
                       final int positionToRemove = position;
                       adb.setNegativeButton("Cancel", null);
                       adb.setPositiveButton("Ok", new AlertDialog.OnClickListener() {
                           public void onClick(DialogInterface dialog, final int which) {                                                                                               
                               new Thread(){
                                    public void run(){
                                        try{
                                             httpclient = new DefaultHttpClient();
                                             httppost = new HttpPost("http://www.kryptoquest.com/tracker/remove.php");
                                             nameValuePairs = new ArrayList<NameValuePair>(2);
                                             Log.d("12345678",user); 
                                             nameValuePairs.add(new BasicNameValuePair("Targetname", (String) lv.getItemAtPosition(position)));
                                             nameValuePairs.add(new BasicNameValuePair("Username", user));
                                             httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                                             response = httpclient.execute(httppost);
                                             is = response.getEntity().getContent();
                                        }catch(Exception e){
                                            Log.e("log_tag", "Error:"+e.toString());
                                        }

                                        //convert response to string
                                        try{
                                                reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
                                                sb = new StringBuilder();
                                                line = null;
                                                while ((line = reader.readLine()) != null) {

                                                        sb.append(line + "\n");

                                                }
                                                Log.d("test",sb.toString());
                                                is.close();

                                                result = sb.toString();                                                     

                                            runOnUiThread(new Runnable()
                                           {
                                               public void run()
                                               {
                                                 Toast.makeText(ThirdActivity.this, result +  lv.getItemAtPosition(position), Toast.LENGTH_LONG).show();
                                               }
                                           });
                                        }catch(Exception e){
                                                Log.e("log_tag", "Error converting result "+e.toString());
                                        }
                                    }
                                }.start();
                               String delete = (String) ((lv.getAdapter()).getItem(which));
                               friend.remove(delete);
                               friend.trimToSize();
                               adapter.notifyDataSetChanged();   

                           }});
                       adb.show();
                   }
               }  
        });  
         AlertDialog ad = adb.create(); 
         ad.show();       
    }

Answer 1

if(item[which].equals("Track Location"))

“item”是您提交给Adapter的数据集，您应该使用position代替which

Answer 2

替换

String delete = (String) ((lv.getAdapter()).getItem(which));

与

String delete = (String) ((lv.getAdapter()).getItem(position));

java.lang.ArrayIndexOutOfBoundsException：length = 1;指数= -1

2 个答案: