清除「緩存」的onDestroy

我嘗試做清除「緩存」的onDestroy

我建立了我的頻道應用程序。我從Google獲取JSON數據，並通過SimpleAdapter將其填充到我的ListView中。

我可以在我的SimpleAdapter中顯示圖片，我將它們保存到我的SD卡上。現在的問題是，當應用程序被殺時，我得到了一個forceclose錯誤，因爲這些圖片已經準備好了。

問題

我怎麼能delte上的onDestroy我的SD卡的「網頁快照」影像（）？

在這裏你可以找到應用程序的代碼。提前謝謝你的幫助！

如果用戶卸載應用程序的外部存儲

代碼

ChannelActivity.java

package de.stepforward; 

import java.io.BufferedInputStream; 
import java.io.BufferedReader; 
import java.io.File; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.URI; 
import java.net.URL; 
import java.net.URLConnection; 
import java.util.ArrayList; 
import java.util.HashMap; 
import java.util.Map; 


import org.apache.http.util.ByteArrayBuffer; 
import org.json.JSONArray; 
import org.json.JSONObject; 

import de.stepforward.web.ShowVideo; 


import android.app.ListActivity; 
import android.content.Intent; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.drawable.BitmapDrawable; 
import android.graphics.drawable.Drawable; 
import android.os.Bundle; 
import android.os.Environment; 
import android.util.Log; 
import android.view.View; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.AdapterView; 
import android.widget.ImageView; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 



public class ChannelActivity extends ListActivity { 


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

    //Cache löschen wenn Applikation gekillt wird 


    String result = ""; 
    String line = null; 
    final ArrayList<HashMap<String, Object>> mylist = new ArrayList<HashMap<String, Object>>(); 


    //get the Data from URL 
    try{ 
    URL url = new URL("http://gdata.youtube.com/feeds/mobile/users/TheStepForward/uploads?alt=json&format=1"); 

    URLConnection conn = url.openConnection(); 
    StringBuilder sb = new StringBuilder(); 
    BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream())); 

    //read d response till d end 
    while ((line = rd.readLine()) != null) { 
    sb.append(line + "\n"); 
    } 
    result = sb.toString(); 
    Log.v("log_tag", "Append String " + result); 
    } catch (Exception e) { 
    Log.e("log_tag", "Error converting result " + e.toString()); 
    } 

    try{ 
     JSONObject json = new JSONObject(result); 
     JSONObject feed = json.getJSONObject("feed"); 
     JSONArray entrylist = feed.getJSONArray("entry"); 

     for(int i=0;i<entrylist.length();i++){ 
      //Get Title 
      JSONObject movie = entrylist.getJSONObject(i); 
      JSONObject title = movie.getJSONObject("title"); 
      String txtTitle = title.getString("$t"); 
      Log.d("Title", txtTitle); 

      //Get Description 
      JSONObject content = movie.getJSONObject("content"); 
      String txtContent = content.getString("$t"); 
      Log.d("Content", txtContent); 

      //Get Link 
      JSONArray linklist = movie.getJSONArray("link"); 
      JSONObject link = linklist.getJSONObject(0); 
      String txtLink = link.getString("href"); 
      Log.d("Link", txtLink); 


      //Get Thumbnail 
      JSONObject medialist = movie.getJSONObject("media$group"); 
      JSONArray thumblist = medialist.getJSONArray("media$thumbnail"); 
      JSONObject thumb = thumblist.getJSONObject(2); 
      String txtThumb = thumb.getString("url"); 
      Log.d("Thumb", txtThumb.toString()); 

      //ImageLoader 

      String name = String.valueOf(i); 
      String test = loadImageFromWebOperations(txtThumb, "StepForward/Cache"+name); 


      //String Array daraus machen und in Hashmap füllen 
      HashMap<String, Object> map = new HashMap<String, Object>(); 
      map.put("Thumb", test); 
      map.put("Title", txtTitle); 
      map.put("Content", txtContent); 
      map.put("Link", txtLink); 
      mylist.add(map); 

     } 
     //ListView füllen 
     ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.lit, 
       new String[] { "Thumb","Title","Content","Link"}, 
       new int[] { R.id.img_video,R.id.txt_title,R.id.txt_subtitle});  
     setListAdapter(adapter); 


     //OnClickLister um Youtube-Video zu öffnen 
     final ListView lv = getListView(); 
      lv.setOnItemClickListener(new OnItemClickListener(){ 
       public void onItemClick(AdapterView<?> parent, View v, int position, long id) { 

        //Video-Link auslesen 
        Map<String, Object> map = mylist.get(position); 
        String link = (String) map.get("Link"); 
        Log.d("Link", link); 

        //Link übergeben, Activity starter 
        final Intent Showvideo = new Intent(ChannelActivity.this, ShowVideo.class); 
        Showvideo.putExtra("VideoLink", link); 
        startActivity(Showvideo); 


       } 
      }); 


    }catch (Exception e) { 
     Log.e("log_tag", "Error converting result " + e.toString()); 
     } 
    } 


    //Path-Loader 
    public static String loadImageFromWebOperations(String url, String path) { 
     try { 
      InputStream is = (InputStream) new URL(url).getContent(); 

      System.out.println(path); 
      File f = new File(Environment.getExternalStorageDirectory(), path); 

      f.createNewFile(); 
      FileOutputStream fos = new FileOutputStream(f); 
      try { 

       byte[] b = new byte[100]; 
       int l = 0; 
       while ((l = is.read(b)) != -1) 
        fos.write(b, 0, l); 

      } catch (Exception e) { 

      } 

      return f.getAbsolutePath(); 
     } catch (Exception e) { 
      System.out.println("Exc=" + e); 
      return null; 

     } 
    } 

}

來源

2011-11-30 safari

其不需要的，因爲它的形象媒體鏈接退出，因爲該ID想清除的onDestroy的chached文件。 – safari

有些奇怪的... – user370305