在我的应用中，我有一个列表视图。每个listview项都包含一个图像视图和几个textview。要显示图像，我使用Drawable。但滚动时图像显示在错误的行中。连续的图像会多次更改，直到出现右图。我在网上搜索过，但发现没有任何对我有用的东西。我在下面发布我的代码。请帮我！提前谢谢！
MainActivity.java
package com.makemyandroidapp.example.stacksites;
import java.io.FileNotFoundException;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends Activity {
private SitesAdapter mAdapter;
private ListView sitesList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.i("StackSites", "OnCreate()");
setContentView(R.layout.activity_main);
//Get reference to our ListView
sitesList = (ListView)findViewById(R.id.sitesList);
//Set the click listener to launch the browser when a row is clicked.
sitesList.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v, int pos,long id) {
String posID = mAdapter.getItem(pos).getID();
Intent i = new Intent(getApplicationContext(), PositionDesc.class);
i.putExtra("posID", posID);
startActivity(i);
}
});
/*
* If network is available download the xml from the Internet.
* If not then try to use the local file from last time.
*/
if(isNetworkAvailable()){
Log.i("StackSites", "starting download Task");
SitesDownloadTask download = new SitesDownloadTask();
download.execute();
}else{
mAdapter = new SitesAdapter(getApplicationContext(), -1, SitesXmlPullParser.getStackSitesFromFile(MainActivity.this, "StackSites.xml"));
sitesList.setAdapter(mAdapter);
}
}
//Helper method to determine if Internet connection is available.
private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager
= (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}
/*
* AsyncTask that will download the xml file for us and store it locally.
* After the download is done we'll parse the local file.
*/
private class SitesDownloadTask extends AsyncTask<Void, Void, Void>{
@Override
protected Void doInBackground(Void... arg0) {
//Download the file
try {
Downloader.DownloadFromUrl("https://duapune.com/mobile/listaeplote.php", openFileOutput("StackSites.xml", Context.MODE_PRIVATE));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result){
//setup our Adapter and set it to the ListView.
mAdapter = new SitesAdapter(MainActivity.this, -1, SitesXmlPullParser.getStackSitesFromFile(MainActivity.this, "StackSites.xml"));
sitesList.setAdapter(mAdapter);
Log.i("StackSites", "adapter size = "+ mAdapter.getCount());
}
}
@Override
public void onBackPressed() {
// TODO Auto-generated method stub
Intent objIntent = new Intent(getApplication(), TabActivity.class);
finish();
startActivity(objIntent);
}
}
SitesAdapter.java
package com.makemyandroidapp.example.stacksites;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.List;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.view.View.OnClickListener;
/*
* Custom Adapter class that is responsible for holding the list of sites after they
* get parsed out of XML and building row views to display them on the screen.
*/
public class SitesAdapter extends ArrayAdapter<StackSite> {
//ImageLoader imageLoader;
//DisplayImageOptions options;
Context c;
String url1;
String url2;
Drawable backgr;
ImageView iconImg;
int posi;
RelativeLayout row;
public SitesAdapter(Context ctx, int textViewResourceId, List<StackSite> sites) {
super(ctx, textViewResourceId, sites);
c=ctx;
}
@Override
public View getView(int pos, View convertView, ViewGroup parent){
posi=pos;
row = (RelativeLayout)convertView;
Log.i("StackSites", "getView pos = " + pos);
if(null == row){
//No recycled View, we have to inflate one.
LayoutInflater inflater = (LayoutInflater)parent.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = (RelativeLayout)inflater.inflate(R.layout.row_site, null);
}
//Get our View References
final TextView kompaniaTxt = (TextView)row.findViewById(R.id.nameTxt);
TextView pozicioniTxt = (TextView)row.findViewById(R.id.aboutTxt);
final TextView kategoriaTxt = (TextView)row.findViewById(R.id.kategoriaTxt);
TextView qytetiTxt = (TextView)row.findViewById(R.id.qytetiTxt);
//final ProgressBar indicator = (ProgressBar)row.findViewById(R.id.progress);
kompaniaTxt.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//String emri_komp=kompaniaTxt.getText().toString().replaceAll("\\s+","%20");
String emri_komp=kompaniaTxt.getText().toString();
Intent intent=new Intent(c,CompanyDesc.class);
intent.putExtra("emri_komp", emri_komp);
intent.putExtra("url1", url1);
c.startActivity(intent);
}
});
kategoriaTxt.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
String idKateg=getItem(posi).getIdKategoria();
Intent intent=new Intent(c,CategoryList.class);
intent.putExtra("idKateg", idKateg);
intent.putExtra("url2", url2);
c.startActivity(intent);
}
});
//Set the relavent text in our TextViews
kompaniaTxt.setText(getItem(pos).getKompania());
pozicioniTxt.setText(getItem(pos).getPozicioni());
kategoriaTxt.setText(getItem(pos).getKategoria());
qytetiTxt.setText(getItem(pos).getQyteti());
url1=getItem(pos).getImgUrl();
SitesDownloadTask download=new SitesDownloadTask();
download.execute();
return row;
}
private class SitesDownloadTask extends AsyncTask<Void, Void, Void>{
@Override
protected Void doInBackground(Void... arg0) {
try { iconImg = (ImageView)row.findViewById(R.id.iconImg);
backgr=drawable_from_url(url1,"kot");
//backgr=drawable_from_url("https://duapune.com/photos/duapune@duapune.com1349707357.png","kot");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result){
iconImg.setBackground(backgr);
}
Drawable drawable_from_url(String url, String src_name) throws
java.net.MalformedURLException, java.io.IOException
{System.out.println("uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu");
return Drawable.createFromStream(((java.io.InputStream)
new java.net.URL(url.trim()).getContent()), src_name);
}
}
}
答案 0 :(得分：1)
试试这个..
您必须使用ViewHolder来解决该问题
private class ViewHolder {
ImageView iconImg;
TextView kompaniaTxt,pozicioniTxt,kategoriaTxt,qytetiTxt;
}
修改
public View getView(final int position, View convertView, ViewGroup parent) {
View view = convertView;
final ViewHolder holder;
if (convertView == null) {
view = getActivity().getLayoutInflater().inflate(R.layout.row_site, parent, false);
holder = new ViewHolder();
holder.iconImg = (ImageView) view.findViewById(R.id.iconImg);
holder.kompaniaTxt = (TextView) view.findViewById(R.id.nameTxt);
holder.pozicioniTxt = (TextView) view.findViewById(R.id.aboutTxt);
//holder.kategoriaTxt = (TextView) view.findViewById(R.id.kategoriaTxt);
holder.qytetiTxt = (TextView) view.findViewById(R.id.qytetiTxt);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
holder.kompaniaTxt.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//String emri_komp=kompaniaTxt.getText().toString().replaceAll("\\s+","%20");
String emri_komp=holder.kompaniaTxt.getText().toString();
Intent intent=new Intent(c,CompanyDesc.class);
intent.putExtra("emri_komp", emri_komp);
intent.putExtra("url1", url1);
c.startActivity(intent);
}
});
holder.kategoriaTxt.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
String idKateg=getItem(posi).getIdKategoria();
Intent intent=new Intent(c,CategoryList.class);
intent.putExtra("idKateg", idKateg);
intent.putExtra("url2", url2);
c.startActivity(intent);
}
});
//Set the relavent text in our TextViews
holder.kompaniaTxt.setText(getItem(pos).getKompania());
holder.pozicioniTxt.setText(getItem(pos).getPozicioni());
holder.kategoriaTxt.setText(getItem(pos).getKategoria());
holder.qytetiTxt.setText(getItem(pos).getQyteti());
url1=getItem(pos).getImgUrl();
SitesDownloadTask download=new SitesDownloadTask();
download.execute();
return view;
}
和onPostExecute
@Override
protected void onPostExecute(Void result){
holder.iconImg.setBackground(backgr);
}
修改
而不是使用SitesDownloadTask AsyncTask使用Universal Image Loader lib