Android 在listView中加载异步映像
在列表视图中加载数据后,我想从服务器加载图像。 我知道这个问题有很多话题,但我还没有找到解决办法 这是我的代码:Android 在listView中加载异步映像,android,listview,asynchronous,Android,Listview,Asynchronous,在列表视图中加载数据后,我想从服务器加载图像。 我知道这个问题有很多话题,但我还没有找到解决办法 这是我的代码: //asyncTackClass for loadingpictures public class LoadImagesThread extends AsyncTask<Bundle, Void, Bitmap> { private ImageView view; private Bitmap bm; private Context context
//asyncTackClass for loadingpictures
public class LoadImagesThread extends AsyncTask<Bundle, Void, Bitmap> {
private ImageView view;
private Bitmap bm;
private Context context;
private final WeakReference<ImageView> imageViewReference;
private final String BUNDLE_URL = "url";
private final String BUNDLE_NAME = "name";
private final String BUNDLE_BM = "bm";
public LoadImagesThread(Context context, ImageView view) {
this.context=context;
imageViewReference = new WeakReference<ImageView>(view);
}
@Override
protected Bitmap doInBackground(Bundle... b) {
Bitmap bm =null;
if (StorageHelper.getBitmap(b[0].getString(BUNDLE_NAME)) != null) { // Check the sdcard
bm = StorageHelper.getBitmap(b[0].getString(BUNDLE_NAME));
Log.w("LoadImagesThread", "Get image from sdcard : "+b[0].getString(BUNDLE_NAME));
} else { // Check the server
bm = ServiceHelper.getBitmapFromURL(b[0].getString(BUNDLE_URL));
StorageHelper.saveBitmap(bm, b[0].getString(BUNDLE_NAME)); // Save image on sdcard
Log.w("LoadImagesThread", "Get image from server : "+b[0].getString(BUNDLE_NAME));
}
return bm;
}
@Override
protected void onPostExecute(final Bitmap bm) {
super.onPostExecute(bm);
if (bm != null){ //if bitmap exists...
view = imageViewReference.get();
// Fade out
Animation fadeOutAnimation = AnimationUtils.loadAnimation(context, R.anim.fadeoutimage);
fadeOutAnimation.setAnimationListener(new AnimationListener() {
public void onAnimationStart(Animation animation) {
}
public void onAnimationRepeat(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
// Fade in
view.setImageBitmap(bm);
Animation fadeInAnimation = AnimationUtils.loadAnimation(context, R.anim.fadeinimage);
view.startAnimation(fadeInAnimation);
}
});
// Launch the fadeout
view.startAnimation(fadeOutAnimation);
}else{ //if not picture, display the default ressource
view.setImageResource(R.drawable.productcarre);
}
}
}
//用于加载图片的asyncTackClass
公共类LoadImagesThread扩展异步任务{
私有图像视图;
私有位图bm;
私人语境;
私有最终WeakReference imageViewReference;
私有最终字符串包\u URL=“URL”;
私有最终字符串包\u NAME=“NAME”;
专用最终字符串束\u BM=“BM”;
公共LoadImagesThread(上下文上下文,ImageView){
this.context=context;
imageViewReference=新的WeakReference(视图);
}
@凌驾
受保护位图doInBackground(束…b){
位图bm=null;
如果(StorageHelper.getBitmap(b[0].getString(BUNDLE_NAME))!=null){//检查SD卡
bm=StorageHelper.getBitmap(b[0].getString(BUNDLE_NAME));
Log.w(“LoadImagesThread”,“从SD卡获取图像:”+b[0].getString(BUNDLE_NAME));
}否则{//请检查服务器
bm=ServiceHelper.getBitmapFromURL(b[0].getString(BUNDLE_URL));
StorageHelper.saveBitmap(bm,b[0].getString(BUNDLE_NAME));//将图像保存到SD卡上
Log.w(“LoadImagesThread”,“从服务器获取图像:”+b[0].getString(BUNDLE_NAME));
}
返回bm;
}
@凌驾
受保护的void onPostExecute(最终位图bm){
super.onPostExecute(bm);
如果(bm!=null){//如果位图存在。。。
view=imageViewReference.get();
//淡出
Animation fadeOutAnimation=AnimationUtils.loadAnimation(上下文,R.anim.fadeoutimage);
setAnimationListener(新建AnimationListener()){
onAnimationStart上的公共无效(动画){
}
onAnimationRepeat上的公共无效(动画){
}
onAnimationEnd上的公共无效(动画){
//淡入
view.setImageBitmap(bm);
Animation fadeInAnimation=AnimationUtils.loadAnimation(上下文,R.anim.fadeinimage);
视图。startAnimation(fadeInAnimation);
}
});
//启动淡出
视图。开始动画(淡出动画);
}否则{//如果不是图片,则显示默认的ressource
view.setImageResource(R.drawable.productcarre);
}
}
}
该代码用于在ImageView中显示位图
这是适配器:
public class ListViewShoplistStoresAdapter extends BaseAdapter {
private ArrayList<Shop> shopList;
private Activity activity;
private HashMap<Integer, ImageView> views;
private final String BUNDLE_URL = "url";
private final String BUNDLE_NAME = "name";
private final String BUNDLE_POS = "pos";
private final String BUNDLE_ID = "id";
public ListViewShoplistStoresAdapter(Activity activity, ArrayList<Shop> shopList) {
super();
this.activity = activity;
this.shopList = shopList;
this.views = new HashMap<Integer, ImageView>();
}
public int getCount() {
return shopList.size();
}
public Object getItem(int position) {
return shopList.get(position);
}
public long getItemId(int position) {
return shopList.get(position).getId();
}
private class ViewHolder {
public TextView store;
public TextView name;
public ImageView ImageStore;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder view;
LayoutInflater inflator = activity.getLayoutInflater();
if(convertView == null) {
view = new ViewHolder();
convertView = inflator.inflate(R.layout.listviewshops, null);
view.store = (TextView) convertView.findViewById(R.id.store);
view.name = (TextView) convertView.findViewById(R.id.name);
view.ImageStore = (ImageView) convertView.findViewById(R.id.imgstore);
convertView.setTag(view);
}else {
view = (ViewHolder) convertView.getTag();
}
Typeface regular=Typeface.createFromAsset(activity.getAssets(), "fonts/RobotoRegular.ttf");
view.store.setTypeface(regular);
Typeface light=Typeface.createFromAsset(activity.getAssets(), "fonts/RobotoLight.ttf");
view.store.setTypeface(light);
Brand brand = StorageHelper.getBrand(activity, shopList.get(position).getBrandId());
if (brand == null) {
Log.e("SetShopInAdapter","Brand null");
Toast.makeText(activity, "Impossible d'afficher la liste de magasins", Toast.LENGTH_LONG).show();
} else {
view.store.setText(brand.getName());
view.name.setText(shopList.get(position).getName());
view.ImageStore.setImageResource(R.drawable.productcarre);
}
Bundle b = new Bundle();
//url of the pict
b.putString(BUNDLE_URL, ServiceHelper.getImageUrl("brand", brand.getName()));
// name of image
b.putString(BUNDLE_NAME, ServiceHelper.getCleanImageName(brand.getName()));
//position in the listView
b.putInt(BUNDLE_POS, position);
//id of the current object
b.putInt(BUNDLE_ID, brand.getId());
//put info in the map in order to display in the onPostExecute
if(views.get(position)==null){
views.put(position, view.ImageStore);
// launch thread
new LoadImagesThread(activity.getApplicationContext(), view.ImageStore).execute(b);
}
return convertView;
}
}
公共类ListViewShoplistStoresAdapter扩展BaseAdapter{
私人ArrayList购物清单;
私人活动;
私有HashMap视图;
私有最终字符串包\u URL=“URL”;
私有最终字符串包\u NAME=“NAME”;
专用最终字符串束\u POS=“POS”;
私有最终字符串束\u ID=“ID”;
public ListViewShoplistStoresAdapter(活动活动,ArrayList商店列表){
超级();
这个。活动=活动;
this.shopList=购物清单;
this.views=newhashmap();
}
public int getCount(){
return shopList.size();
}
公共对象getItem(int位置){
返回购物清单。获取(位置);
}
公共长getItemId(int位置){
return shopList.get(position.getId();
}
私有类视窗持有者{
公共文本视图存储;
公共文本视图名称;
公共图像库;
}
公共视图getView(int位置、视图转换视图、视图组父视图){
视图持有者视图;
LayoutFlater充气器=活动。GetLayoutFlater();
if(convertView==null){
视图=新的ViewHolder();
convertView=充气机。充气(R.layout.listviewshops,null);
view.store=(TextView)convertView.findViewById(R.id.store);
view.name=(TextView)convertView.findViewById(R.id.name);
view.ImageStore=(ImageView)convertView.findViewById(R.id.imgstore);
setTag(视图);
}否则{
view=(ViewHolder)convertView.getTag();
}
Typeface regular=Typeface.createFromAsset(activity.getAssets(),“font/robotregular.ttf”);
view.store.setTypeface(常规);
Typeface light=Typeface.createFromAsset(activity.getAssets(),“font/RobotoLight.ttf”);
view.store.setTypeface(灯光);
Brand Brand=StorageHelper.getBrand(活动,shopList.get(位置).getBrandId());
如果(品牌==null){
Log.e(“SetShopInAdapter”、“品牌空”);
Toast.makeText(活动,“不可能的演讲”,Toast.LENGTH_LONG.show();
}否则{
view.store.setText(brand.getName());
view.name.setText(shopList.get(position.getName());
view.ImageStore.setImageResource(R.drawable.productcarre);
}
Bundle b=新Bundle();
//pict的url
b、 putString(BUNDLE_URL,serviceheloper.getImageUrl(“brand”,brand.getName());
//图像名称
b、 putString(BUNDLE_NAME,serviceheloper.getCleanImageName(brand.getName());
//在listView中的位置
b、 putInt(线束位置、位置);
//当前对象的id
b、 putInt(BUNDLE_ID,brand.getId());
//将信息放入地图中,以便在onPostExecute中显示
if(views.get(position)==null){
视图.放置(位置,视图.图像存储);
//启动线程
新的LoadImagesThread(activity.getApplicationContext(),view.ImageStore).execute(b);
}
返回视图;
}
}
所以,当我使用GridView时,没有问题,但是当我使用ListView时,图像仅在第一项中更改
示例:
我想显示“汽车”、“房子”和“苹果”项目的产品图像。
代码将启动线程,所有图像(汽车、房子、最后是苹果)将显示在第一个项目(汽车项目)中。。。
房子和苹果虽然没有图像
你知道我该怎么做吗
谢谢关于这一点,这里有很多,所以。。 异步的