【移动应用开发技术】ListView 相关使用优化 Day08

【移动应用开发技术】ListView相关使用，优化Day08

packagecom.example.ex_day_0611_day07_listview;importjava.io.IOException;importjava.io.InputStream;import.MalformedURLException;import.URL;import.URLConnection;importjava.security.PublicKey;importjava.util.HashMap;importjava.util.concurrent.Executor;importandroid.os.AsyncTask;importandroid.os.Bundle;importandroid.app.Activity;importandroid.graphics.Bitmap;importandroid.graphics.BitmapFactory;importandroid.view.LayoutInflater;importandroid.view.Menu;importandroid.view.View;importandroid.view.View.OnClickListener;importandroid.view.ViewGroup;importandroid.widget.BaseAdapter;importandroid.widget.Button;importandroid.widget.ImageView;importandroid.widget.ListView;importandroid.widget.ProgressBar;importandroid.widget.TextView;publicclassMainActivityextendsActivity{ HashMap<Integer,Bitmap>map=newHashMap<Integer,Bitmap>(); HashMap<Integer,Boolean>hashmap=newHashMap<Integer,Boolean>(); HashMap<Integer,MyAsyncTask2>myapa=newHashMap<Integer,MyAsyncTask2>(); HashMap<Integer,Integer>myint=newHashMap<Integer,Integer>(); privateListViewlistview; @Override protectedvoidonCreate(BundlesavedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); listview=(ListView)findViewById(R.id.listView1); MyApaptermyApapter=newMyApapter();

listview.setAdapter(myApapter); } classUser { ImageViewp_w_picpathview; ProgressBarpb; TextViewtv; Buttonbutton; }

classMyApapterextendsBaseAdapter

{ @Override

publicViewgetView(intposition,ViewconvertView,ViewGroupparent){

Viewview=null;

Useruser=newUser(); LayoutInflaterinflater=getLayoutInflater(); if(convertView==null) {

view=inflater.inflate(R.layout.itmp,null);

user.p_w_picpathview=(ImageView)view.findViewById(R.id.p_w_picpathView1);

user.pb=(ProgressBar)view.findViewById(R.gressBar1);

user.button=(Button)view.findViewById(R.id.button1);

user.tv=(TextView)view.findViewById(R.id.textView1);

view.setTag(user); }else { view=convertView; user=(User)view.getTag(); } //下载图片 //设置图片还未开始下载时的状态 user.p_w_picpathview.setImageResource(R.drawable.ic_launcher); Bitmapbitmap=map.get(position); if(bitmap==null)

{ MyAsyncTaskmyp_w_picpathview=newMyAsyncTask(user.p_w_picpathview,position,user.pb); myp_w_picpathview.execute(":8080/service/qq"+position+".png"); }else { user.p_w_picpathview.setImageBitmap(bitmap); } //实现按钮点击事件 finalButtonbutton1=user.button; finalintpos=position; finalProgressBarpb1=user.pb; finalTextViewtv=user.tv; button1.setOnClickListener(newOnClickListener(){ @Override publicvoidonClick(Viewv){

button1.setText("下载中");

button1.setEnabled(false);

MyAsyncTask2myasyctask2=newMyAsyncTask2(button1,pb1,tv,pos);

myapa.put(pos,myasyctask2);

myasyctask2.execute(":8080/service/qq"+pos+".zip");

hashmap.put(pos,null); } }); MyAsyncTask2task2=myapa.get(pos); ProgressBarpb2=user.pb; Buttonbutton2=user.button; TextViewtv1=user.tv; //按钮点击事件中设置进度条。 //下文件 if(hashmap.get(position)==null) { button1.setText("下载"); button1.setEnabled(true); user.tv.setText("=========="); pb1.setProgress(0); } elseif(hashmap.get(position)==false) { button1.setText("下载中"); button1.setEnabled(false); user.pb.setMax(myint.get(pos));

task2.setReplace(pb2,button2,tv1);

}elseif(hashmap.get(position)==true) { button1.setText("下载完成"); button1.setEnabled(true); user.tv.setText("=========="); pb1.setMax(100); pb1.setProgress(100); } returnview;

} @Override publicintgetCount(){ return20; } @Override publicObjectgetItem(intposition){ returnnull; } @Override publiclonggetItemId(intposition){ return0; }

}

classMyAsyncTask2extendsAsyncTask<String,Integer,String>

{

Buttonbutton1;

ProgressBarpb;

TextViewtv;

intposition; publicMyAsyncTask2(Buttonbutton1,ProgressBarpb,TextViewtv,intposition)

{

this.button1=button1;

this.pb=pb;

this.tv=tv;

this.position=position; } publicvoidsetReplace(ProgressBarpb,Buttonbutton1,TextViewtv) { this.pb=pb; this.button1=button1; this.tv=tv; } @Override protectedStringdoInBackground(String...params){

try{ URLurl=newURL(params[0]); URLConnectionopenConnection=url.openConnection(); intcontentLength=openConnection.getContentLength(); myint.put(position,contentLength); pb.setMax(contentLength); InputStreaminputStream=openConnection.getInputStream(); byte[]buffer=newbyte[1024]; intsum=0; intlen=0; hashmap.put(position,false); while(-1!=(len

=inputStream.read(buffer))) {

sum+=len;

Thread.sleep(100);

publishProgress(sum); } hashmap.put(position,true); }catch(MalformedURLExceptione){ e.printStackTrace(); }catch(IOExceptione){ e.printStackTrace(); }catch(InterruptedExceptione){ e.printStackTrace(); } return"下载完成"; } @Override protectedvoidonPostExecute(Stringresult){

button1.setText(result);

button1.setEnabled(true); super.onPostExecute(result); } @Override protectedvoidonProgressUpdate(Integer...values){ intfp=listview.getFirstVisiblePosition(); intlp=listview.getLastVisiblePosition(); if(position>=fp&&position<=lp){ pb.setProgress(values[0]); tv.setText((int)((double)values[0]/(double)pb.getMax()*100)+"%"); } super.onProgressUpdate(values); }

}

classMyAsyncTaskextendsAsyncTask<String,Void,Bitmap>

{

intposition;

ImageViewp_w_picpathview;

ProgressBarpb; publicMyAsyncTask(ImageViewp_w_picpathview,intposition,ProgressBarpb){ this.p_w_picpathview=p_w_picpathview; this.position=position; this.pb=pb; } @Override protectedBitmapdoInBackground(String...params){ Bitmapbitmap=null;

try{ URLurl=newURL(params[0]); URLConnectionconnection=url.openConnection(); InputStreamis=connection.getInputStream(); bitma