提高活动绩效的建议？

Question

朋友，

我使用按照我的活动全局变量

private String Session_ID; 
    private String uid; 

    // menu item starts 
    private final int Trash = 0x003; 
    private final int More = 0x005; 
    private final int SignOut = 0x006; 
    private final int SignIn = 0x007; 
    //menu item ends 

    private EfficientAdapter adap; 

    private String[] Msg_id; 
    private String[] Msg_body; 
    private String[] Sent_by; 
    private String[] Sent_on; 
    private String[] Is_my_message; 
    private String[] Photo_thumbnail; 
    private String[] Photo_full_path; 


    private String Conversation_id; 
    ProgressBar progressBar; 
    Button getMoreButton; 


    boolean callComplete = false; 
    private Handler mHandler = new Handler(); 
    private int PageSize = Constants.pageSizeForMessages; 
    Object serviceData = null; 


    private String ConversationName; 
    private Uri selectedImage; 





public class EfficientAdapter extends BaseAdapter implements Filterable { 
        private LayoutInflater mInflater; 
        private Context context; 

        public EfficientAdapter(Context context) { 
         mInflater = LayoutInflater.from(context); 
         this.context = context; 
        } 


        public View getView(final int position, View convertView, ViewGroup parent) { 
         ViewHolder holder; 
         convertView = mInflater.inflate(R.layout.adaptor_contentmessagedetail, null); 
         holder = new ViewHolder(); 

         holder.ImgPhoto = (ImageView)convertView.findViewById(R.id.ImgPhoto); 
         holder.lblMsgSentBy = (TextView) convertView.findViewById(R.id.lblSentBy); 
         holder.lblMsgBody = (TextView) convertView.findViewById(R.id.lblMessageBody); 
         holder.lblMsgSentOn = (TextView) convertView.findViewById(R.id.lblSentOn); 


         convertView.setOnClickListener(new OnClickListener() { 
           @Override 
           public void onClick(View v) { 

            if (!((MessageDetail)v.getContext()).isConnected()) { 
             Constants.DisplayMessage(v.getContext(), 
               Constants.CONNECTION_ERROR_MESSAGE); 
             return; 
            } 


            if(!Photo_full_path[position].equals("")) 
            { 

             String str= Photo_full_path[position].substring(Photo_full_path[position].length() - 3); 
             if(str.equals("pdf")) 
             { 


             }else 
             { 

            Intent myIntent = new Intent(v.getContext(), ViewSingleImage.class); 
            Bundle b = new Bundle(); 
            b.putString("single_image_path", Photo_full_path[position]); 
            myIntent.putExtras(b); 
            v.getContext().startActivity(myIntent); 
             } 

            } 

           } 
          }); 





         convertView.setTag(holder); 


         // Bind the data efficiently with the holder. 

         if(Is_my_message[position].equals("1")) 
          holder.lblMsgSentBy.setTextColor(Color.BLACK); 
          else 
          holder.lblMsgSentBy.setTextColor(Color.rgb(255, 107, 1)); 



        SimpleDateFormat fromUser = new SimpleDateFormat(Constants.SERVICE_DATE_FORMAT); 
        java.text.DateFormat df=new SimpleDateFormat(Constants.DATE_FORMAT);       
        Date dt=new Date(); 
        try 
        { 
         dt = fromUser.parse(Sent_on[position]); 

        } catch (java.text.ParseException e) { 
         e.printStackTrace(); 
        } 





        // display photo 
        if(!Photo_thumbnail[position].equals("")) 
        { 

        // resize it 
         holder.ImgPhoto.setImageBitmap(DisplayLiveImage(Photo_thumbnail[position])); 

        }else 
        { 
         holder.ImgPhoto.setVisibility(View.GONE); 

        } 
        // display photo 



         holder.lblMsgSentBy.setText(Constants.GetSpecialCharacters(Sent_by[position])); 
         holder.lblMsgBody.setText(Constants.GetSpecialCharacters(Msg_body[position])); 
         holder.lblMsgSentOn.setText(df.format(dt)); 


         return convertView; 
        } 

        class ViewHolder { 

         ImageView ImgPhoto; 
         TextView lblMsgSentBy; 
         TextView lblMsgBody; 
         TextView lblMsgSentOn; 

        } 

        @Override 
        public Filter getFilter() { 
         // TODO Auto-generated method stub 
         return null; 
        } 

        @Override 
        public long getItemId(int position) { 
         // TODO Auto-generated method stub 
         return 0; 
        } 

        @Override 
        public int getCount() { 
         // TODO Auto-generated method stub 
         return Msg_id.length; 
        } 

        @Override 
        public Object getItem(int position) { 
         // TODO Auto-generated method stub 
         return Msg_id[position]; 
        } 

        } 

public Bitmap DisplayLiveImage(String ImageSrc) 
     { 
      Bitmap bm; 
         try { 

           URL aURL = new URL(ImageSrc); 
           URLConnection conn = aURL.openConnection(); 

           conn.connect(); 
           InputStream is = null; 
           try 
           { 
            is= conn.getInputStream(); 
           }catch(IOException e) 
           { 
            return null; 
           } 

           BufferedInputStream bis = new BufferedInputStream(is); 

           bm = BitmapFactory.decodeStream(bis); 
           bis.close(); 
           is.close(); 

          } catch (IOException e) { 
           return null; 
          } 

          return bm; 

     } 

我已经让他们全球的活动，因为我需要他们所有超过1个功能 现在我的问题是如何提高性能我的活动太慢了 我应该让它们变成静态还是什么？

任何帮助，将不胜感激。

Answer 1

建议缓存图像，不要一次又一次地将它们从互联网上带回来。

所以我的情况，而使用自定义适配器和滚动它一次又一次地加载图像从互联网 这是造成糟糕的表现。

也有内存泄漏问题。

所以我做了什么我也跟着下面的教程来加载实时图像和我的问题解决

答：LazyList

http://mobilebitworks.wordpress.com/2010/11/05/android-listview-and-dynamically-loading-images-from-the-web

Answer 2

你的全局变量几乎肯定不是你糟糕的表现的原因。除非你访问他们一百万次，否则它一定是别的。如果您告诉我们执行速度比您期望的要慢，并发布相关代码，我们可能会提供帮助。

您的getView()方法中有很多代码。这个方法在每次显示新视图时都会被调用。所以当listview被创建时，它被称为N次，其中N是被看到的列表元素的数量。然后当您滚动时，每次有新元素进入屏幕时，getView()会再次被调用。即使您再次向上滚动，它也会再次调用getView()。

您需要重构代码，每次创建视图时不需要运行该代码。