我有自定义arrayadapter的gridview。 在滚动图像时随机播放。我确定适配器有问题。我错过了什么。我已经发布了适配器的代码。
公共类CustomAdapterForDealsGrid扩展了ArrayAdapter {
private final boolean checkBoxState[] ;
private TCLruCache cache;
Context context;
int layoutResourceId;
private BtnClickListener mClickListener = null;
private OnClickListener clickListner = null;
ArrayList<Ads> data = new ArrayList<Ads>();
Map<String,Bitmap> imageMap = new HashMap<String, Bitmap>();
public CustomAdapterForDealsGrid(Context context, int resource,
ArrayList<Ads> objects,BtnClickListener listener) {
super(context, resource, objects);
ActivityManager am = (ActivityManager) context.getSystemService(
Context.ACTIVITY_SERVICE);
int memoryClass = am.getMemoryClass() * 1024 * 1024;
cache = new TCLruCache(memoryClass);
this.layoutResourceId = resource;
this.context = context;
this.data = objects;
checkBoxState=new boolean[this.data.size()];
mClickListener = listener;
//new GetImageAsync().execute();
}
private class GetImageAsync extends AsyncTask<Void, Void, Boolean> {
@Override
protected Boolean doInBackground(Void... arg0) {
setImageMap();
return null;
}
}
public void setImageMap(){
for(Ads ads : data){
try {
imageMap.put("http://"+ApplicationConstant.host+ "/"+ads.getImagepath(),getImageFromUrl("http://"+ApplicationConstant.host+ "/"+ads.getImagepath()));
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
@Override
public int getCount() {
return data.size();
}
@Override
public Ads getItem(int item) {
return data.get(item);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View row = convertView;
DealHolder holder = null;
if (row == null) {
LayoutInflater inflater = ((Activity) context).getLayoutInflater();
row = inflater.inflate(layoutResourceId, parent, false);
holder = new DealHolder();
holder.imageItem = (ImageView) row.findViewById(R.id.item_deal);
holder.txtURL =(TextView) row.findViewById(R.id.item_url);
holder.txtDesc =(TextView) row.findViewById(R.id.item_desc);
holder.chkGrid = (CheckBox)row.findViewById(R.id.chkGrid);
holder.txtPrice =(TextView) row.findViewById(R.id.item_price);
holder.button = (Button) row.findViewById(R.id.btnDeal);
holder.button.setTag(Integer.valueOf(position));
holder.button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if(mClickListener != null)
mClickListener.onBtnClick((Integer)v.getTag());
}
});
row.setTag(holder);
} else {
holder = (DealHolder) row.getTag();
}
if(holder.setFlag!=true){
Ads ads = data.get(position);
holder.imageItem.setImageResource(R.drawable.powerelectronics);
holder.txtPrice.setText(ads.getPricerange());
holder.txtURL.setText(ads.getUrl());
holder.txtDesc.setText(ads.getDesc());
holder.chkGrid.setChecked(checkBoxState[position]);
holder.chkGrid.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if(((CheckBox)v).isChecked()){
checkBoxState[position]=true;
data.get(position).setChecked(true);
}else{
checkBoxState[position]=false;
data.get(position).setChecked(false);
}
}
}
);
try {
if(cache.get("http://"+ApplicationConstant.host+ "/"+ads.getImagepath()) != null){
holder.imageItem.setImageBitmap(cache.get("http://"+ApplicationConstant.host+ "/"+ads.getImagepath()));
}
else{
BitmapFactory.decodeResource(context.getResources(), R.drawable.abs__activated_background_holo_light));
setBitmap(holder.imageItem, "http://"+ApplicationConstant.host+ "/"+ads.getImagepath(),ads.getDesc());
}
holder.setFlag = true;
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return row;
}
static class DealHolder {
TextView txtPrice,txtURL,txtDesc;
ImageView imageItem;
Button button;
CheckBox chkGrid;
Boolean setFlag = new Boolean(false);
}
public Bitmap getImageFromUrl(String imgPath) throws Exception{
HttpGet httpRequest = null;
URL url = new URL(imgPath);
httpRequest = new HttpGet(url.toURI());
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = (HttpResponse) httpclient
.execute(httpRequest);
HttpEntity entity = response.getEntity();
BufferedHttpEntity b_entity = new BufferedHttpEntity(entity);
InputStream input = b_entity.getContent();
Bitmap bitmap = BitmapFactory.decodeStream(input);
return bitmap;
}
private Bitmap methodScaledImage(int width,int height,Bitmap origBitmap) throws FileNotFoundException{
Bitmap background = Bitmap.createBitmap((int)width, (int)height, Config.ARGB_8888);
float originalWidth = origBitmap.getWidth(), originalHeight = origBitmap.getHeight();
Canvas canvas = new Canvas(background);
float scale = width/originalWidth;
float xTranslation = 0.0f, yTranslation = (height - originalHeight * scale)/2.0f;
Matrix transformation = new Matrix();
transformation.postTranslate(xTranslation, yTranslation);
transformation.preScale(scale, scale);
Paint paint = new Paint();
paint.setFilterBitmap(true);
canvas.drawBitmap(origBitmap, transformation, paint);
return background;
}
private void setBitmap(final ImageView iv, final String path,final String desc) {
new AsyncTask<Void, Void, Bitmap>() {
@Override
protected Bitmap doInBackground(Void... params) {
Bitmap imageBtMP= null;
try {
imageBtMP = getImageFromUrl(path);
if(imageBtMP!= null){
cache.put(path, imageBtMP);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return imageBtMP;
}
@Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
iv.setImageBitmap(result);
iv.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
LayoutInflater layoutInflater = LayoutInflater.from(getContext());
View popupView = layoutInflater.inflate(R.layout.activity_desc_deal, null);
final PopupWindow popupWindow = new PopupWindow(
popupView,
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
final TextView descTextview = (TextView) popupView.findViewById(R.id.descdeal);
descTextview.setText(desc);
Button btnDismiss = (Button)popupView.findViewById(R.id.dismiss);
btnDismiss.setOnClickListener(new Button.OnClickListener(){
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
popupWindow.dismiss();
}});
popupWindow.showAsDropDown(v, 50, -30);
}
});
}
}.execute();
}
private class TCLruCache extends LruCache<String, Bitmap> {
public TCLruCache(int maxSize) {
super(maxSize);
}
}
}
答案 0 :(得分：1)
问题与您的setBitmap()方法有关。在整个异步期间，绝对不能保证您传入的ImageView与Bitmap中的onPostExecute()相同。这是由于适配器的View回收所致。此外，您必须将ImageView存储为WeakReference。否则你冒险泄漏它。
你的异步应该更像这样：
private class ExampleAsync extends AsyncTask<Void, Void, Bitmap> {
private WeakReference<ImageView> mImageViewRef;
private String mPath;
private String mDesc;
public ExampleAsync(ImageView iv, String path, String desc) {
iv.setTag(path); //Records which path the ImageView represents
mImageViewRef = new WeakReference<ImageView>(iv);
mPath = path;
mDesc = desc;
}
@Override
protected Bitmap doInBackground(Void... params) {
ImageView iv = mImageViewRef.get();
if (iv == null || !mPath.equals(iv.getTag())) {
return null;
}
//Retrieve bitmap logic. Return results or null if it fails
}
@Override
protected void onPostExecute(Bitmap bitmap) {
ImageView iv = mImageViewRef.get();
if (iv == null || bitmap == null || !mPath.equals(iv.getTag())) {
//In an invalid state or results had error. Ignore everything and just exit Async.
return;
}
//Received valid results and in good state. Set ImageView and do all your other logic
}
}
这只是一个粗略的草图，但应该得到重点。这将处理使用适配器和/或在用户滚动期间呈现视图的不同结果。当ImageView被回收并用于其他位置时，记录ImageView标记内的路径。存储在WeakReference中可确保实际销毁ImageView被销毁。否则，您将保留引用并继续加载并在其中放置Bitmap。您始终无效检查引用以确保View未被销毁。使用时，您总是暂时存储在局部变量中以防止它被GC。