代码之家 › 专栏 › 技术社区 › UMAR-MOBITSOLUTIONS

提高活动绩效的建议?

android-activity android

UMAR-MOBITSOLUTIONS · 技术社区 · 15 年前

我在活动中使用以下全局变量

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;

        }

我已经使它们在活动中全球化,因为我需要它们在1个以上的函数中现在我的问题是如何提高我的活动表现太慢了我应该让它们静止还是什么?

任何帮助都将不胜感激。

2 回复 | 直到 15 年前

Falmarri 15 年前

你的全局变量几乎肯定不是你表现不佳的原因。除非你访问了一百万次,否则肯定是别的什么东西。如果你告诉我们什么比你预期的执行速度慢,并发布相关代码,我们可能会提供帮助。

你的代码太多了 getView() 方法。每次显示新视图时都会调用此方法。所以当listview被创建时,它被调用N次,其中N是所看到的列表元素的数量。当你滚动的时候,每次一个新的元素出现在屏幕上, 获取视图() 又接到电话了。即使你再向上滚动,它也会调用 获取视图() 再一次。

UMAR-MOBITSOLUTIONS 15 年前

建议您缓存图像,不要一次又一次地从internet将它们全部带来。

所以我在使用自定义适配器和滚动时,一次又一次地从internet加载图像

还有内存泄漏问题。

因此,我做了什么,我遵循以下教程加载实时图像和我的问题解决了

答:懒汉

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