如何解決java.lang.ClassCastException Android

我有搜索這種情況下，我發現它，但在C＃中。 Oke，我嘗試使用ListFragment android，json和mysql顯示我的數據到listview中，但是當我運行它時我得到了一個錯誤類Cast，我希望任何人都可以幫助我。這裏我的錯誤：如何解決java.lang.ClassCastException Android

06-12 17:04:04.685 20975-20975/com.spp.udi.sppmap E/AndroidRuntime: FATAL EXCEPTION: main 
                    Process: com.spp.udi.sppmap, PID: 20975 
                    java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.spp.udi.sppmap/com.spp.udi.sppmap.Potensi}: java.lang.ClassCastException: com.spp.udi.sppmap.Potensi cannot be cast to android.app.Activity 
                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2345) 
                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2494) 
                     at android.app.ActivityThread.access$900(ActivityThread.java:153) 
                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1347) 
                     at android.os.Handler.dispatchMessage(Handler.java:102) 
                     at android.os.Looper.loop(Looper.java:148) 
                     at android.app.ActivityThread.main(ActivityThread.java:5451) 
                     at java.lang.reflect.Method.invoke(Native Method) 
                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
                    Caused by: java.lang.ClassCastException: com.spp.udi.sppmap.Potensi cannot be cast to android.app.Activity 
                     at android.app.Instrumentation.newActivity(Instrumentation.java:1068) 
                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2335) 
                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2494)  
                     at android.app.ActivityThread.access$900(ActivityThread.java:153)  
                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1347)  
                     at android.os.Handler.dispatchMessage(Handler.java:102)  
                     at android.os.Looper.loop(Looper.java:148)  
                     at android.app.ActivityThread.main(ActivityThread.java:5451)  
                     at java.lang.reflect.Method.invoke(Native Method)  
                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  
                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

我Potensi.java：

package com.spp.udi.sppmap; 

import android.app.Fragment; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ListView; 
import android.app.ListFragment; 
import java.util.ArrayList; 
import java.util.HashMap; 
import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 
import android.util.Log; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ListAdapter; 
import android.widget.SimpleAdapter; 
import android.widget.TextView; 

public class Potensi extends ListFragment { 
    private static final String ID_KECAMATAN = "id_kecamatan"; 
    private static final String NAMA_KECAMATAN = "nama_kecamatan"; 
    ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String,String>>(); 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     JSONObject json = JSONFunction.getJSONFromUrl("http://192.168.43.203/project/s9/udi/android/potensi.php"); 
     try { 
      JSONArray laporan = json.getJSONArray("result"); 
      for(int i=0; i<laporan.length(); i++){ 
       JSONObject jsonobj = laporan.getJSONObject(i); 
       String id_kecamatan = jsonobj.getString(ID_KECAMATAN); 
       String nama_kecamatan = jsonobj.getString(NAMA_KECAMATAN); 
       HashMap<String, String> map = new HashMap<String, String>(); 
       map.put("id_kecamatan", id_kecamatan); 
       map.put("nama_kecamatan", nama_kecamatan); 
       mylist.add(map); 
      } 
     } catch (JSONException e) { 
      Log.e("log_tag","error parsing data "+e.toString()); 
     } 
     this.adapter_listview(); 
    } 

    public void adapter_listview() { 
     ListAdapter adapter = new SimpleAdapter(getActivity(), mylist, R.layout.potensi, 
       new String[] {ID_KECAMATAN, NAMA_KECAMATAN}, new int[] {R.id.id_kecamatan, R.id.nama_kecamatan}); 

     setListAdapter(adapter); 
     ListView lv = getListView(); 
     lv.setOnItemClickListener(new OnItemClickListener() { 
      public void onItemClick(AdapterView<?> parent, View view,int position, long id) { 
       String id_kecamatan = ((TextView) view.findViewById(R.id.id_kecamatan)).getText().toString(); 
       Intent in = new Intent(getActivity(), DetailPotensi.class); 
       in.putExtra(ID_KECAMATAN, id_kecamatan); 
       startActivity(in); 
      } 
     }); 
    } 
}

我的輸出JSON：

{"result":[{"id_kecamatan":"8","nama_kecamatan":"Batang Dua"},{"id_kecamatan":"7","nama_kecamatan":"Pulau Moti"},{"id_kecamatan":"6","nama_kecamatan":"Pulau Hiri"},{"id_kecamatan":"5","nama_kecamatan":"Pulau Ternate"},{"id_kecamatan":"4","nama_kecamatan":"Ternate Utara"},{"id_kecamatan":"3","nama_kecamatan":"Ternate Tengah"},{"id_kecamatan":"2","nama_kecamatan":"Ternate Selatan"}]}

來源

2017-06-12 Muh Fadly Sangadji

'Fragment' - 因此'ListFragment' - 不是'Activity'。也許你打算'擴展ListActivity'來代替。 –

你可以發佈你的活動代碼 –

活動是Okhay .. –

ClassCastException

投擲以表明代碼已嘗試將對象投射到其不屬於實例的子類。

Caused by: java.lang.ClassCastException: com.spp.udi.sppmap.Potensi cannot be cast to android.app.Activity

您正在使用安卓inbuild列表視圖@ + ID /安卓列表

所以，請擴展ListActivity，而不是ListFragment。

public class Potensi extends ListActivity{

來源

2017-06-12 08:24:22

如何解決java.lang.ClassCastException Android

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