如何解决listview数据刷新，下拉刷新，上拉加载更多时，图片不闪烁。
在Activity的onResume()方法中将adaper和listView重新再绑定一次。
listView.setAdapter(adapter);
adapter.notifyDataSetChanged();
http://www.eoeandroid.com/forum.php?mod=viewthread&tid=541113&extra=&ordertype=1
public class HomeWaterfallXlListAdapter extends BaseAdapter {private Bitmap defaultBm; private static final List<String> displayedImages = Collections.synchronizedList(new LinkedList<String>()); public HomeWaterfallXlListAdapter() { defaultBm = BitmapFactory.decodeResource(mActivity.getResources(), R.drawable.loading); } /**刷新视图**/ public void setList(List<HomeAnswersJSONResult.Answer> list) { this.answers = list; notifyDataSetInvalidated(); } /**加载更多**/ public void addList(List<HomeAnswersJSONResult.Answer> list) { if (this.answers != null) { this.answers.addAll(list); notifyDataSetChanged(); } else { setList(list); } } @Override public int getCount() { return answers == null ? 0 : answers.size(); } @Override public Object getItem(int arg0) { return answers.get(arg0); } @Override public long getItemId(int arg0) { return 0; } @Override public View getView(int position, View convertView, ViewGroup parent) { Answer answer = answers.get(position); final ViewHolder holder; if (convertView == null) { convertView = LayoutInflater.from(mActivity).inflate(R.layout.item_home_infos_list, null); holder = new ViewHolder(); holder.imageView = (ScaleImageView) convertView.findViewById(R.id.starImg); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } int w = answer.getImg().getWidth(); int h = answer.getImg().getHeight(); holder.imageView.setImageWidth(w); holder.imageView.setImageHeight(h); String imageUrl = answer.getImg().getUrl().toString() + "?w=" + AppActivity.screenWidth / 2; holder.imageView.setTag(imageUrl); imageLoader.loadImage(imageUrl, new ImageSize(w, h), options, new ImageLoadingListener() { @Override public void onLoadingStarted(String imageUri, View view) { holder.imageView.setImageBitmap(defaultBm); } @Override public void onLoadingFailed(String imageUri, View view, FailReason failReason) { } @Override public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) { if (loadedImage != null && imageUri.equals(holder.imageView.getTag())) { holder.imageView.setImageBitmap(loadedImage); boolean firstDisplay = !displayedImages.contains(imageUri); if (firstDisplay) { // 图片淡入效果 AlphaAnimation fadeImage = new AlphaAnimation(0, 1); fadeImage.setDuration(500); fadeImage.setInterpolator(new DecelerateInterpolator()); holder.imageView.startAnimation(fadeImage); displayedImages.add(imageUri); } } } @Override public void onLoadingCancelled(String imageUri, View view) { } }); convertView.setOnClickListener(new onItemClick(id)); return convertView; } static final class ViewHolder { ScaleImageView imageView; } private class onItemClick implements View.OnClickListener { private int id; public onItemClick(int id) { this.id = id; } @Override public void onClick(View arg0) { Intent intent = new Intent(mActivity, A.class); intent.putExtra("answerId", id); mActivity.startActivity(intent); } } /** * 图片加载第一次显示监听器 * @author Administrator * */ private static class AnimateFirstDisplayListener extends SimpleImageLoadingListener { static final List<String> displayedImages = Collections.synchronizedList(new LinkedList<String>()); @Override public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) { if (loadedImage != null) { ImageView imageView = (ImageView) view; // 是否第一次显示 boolean firstDisplay = !displayedImages.contains(imageUri); if (firstDisplay) { // 图片淡入效果 FadeInBitmapDisplayer.animate(imageView, 500); displayedImages.add(imageUri); } } } } }
ScaleImageView
/** * * This view will auto determine the width or height by determining if the * height or width is set and scale the other dimension depending on the images * dimension * * This view also contains an ImageChangeListener which calls changed(boolean * isEmpty) once a change has been made to the ImageView * * @author Maurycy Wojtowicz * */ public class ScaleImageView extends ImageView { private Bitmap currentBitmap; private ImageChangeListener imageChangeListener; private boolean scaleToWidth = false; // this flag determines if should // measure height manually dependent // of width public ScaleImageView(Context context) { super(context); init(); } public ScaleImageView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } public ScaleImageView(Context context, AttributeSet attrs) { super(context, attrs); init(); } private void init() { this.setScaleType(ScaleType.CENTER_INSIDE); } public void recycle() { setImageBitmap(null); if ((this.currentBitmap == null) || (this.currentBitmap.isRecycled())) return; this.currentBitmap.recycle(); this.currentBitmap = null; } @Override public void setImageBitmap(Bitmap bm) { currentBitmap = bm; super.setImageBitmap(currentBitmap); if (imageChangeListener != null) imageChangeListener.changed((currentBitmap == null)); } @Override public void setImageDrawable(Drawable d) { super.setImageDrawable(d); if (imageChangeListener != null) imageChangeListener.changed((d == null)); } @Override public void setImageResource(int id) { super.setImageResource(id); } public interface ImageChangeListener { // a callback for when a change has been made to this imageView void changed(boolean isEmpty); } public ImageChangeListener getImageChangeListener() { return imageChangeListener; } public void setImageChangeListener(ImageChangeListener imageChangeListener) { this.imageChangeListener = imageChangeListener; } private int imageWidth; private int imageHeight; public void setImageWidth(int w) { imageWidth = w; } public void setImageHeight(int h) { imageHeight = h; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int widthMode = MeasureSpec.getMode(widthMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); int width = MeasureSpec.getSize(widthMeasureSpec); int height = MeasureSpec.getSize(heightMeasureSpec); /** * if both width and height are set scale width first. modify in future * if necessary */ if (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST) { scaleToWidth = true; } else if (heightMode == MeasureSpec.EXACTLY || heightMode == MeasureSpec.AT_MOST) { scaleToWidth = false; } else throw new IllegalStateException("width or height needs to be set to match_parent or a specific dimension"); if (imageWidth == 0) { // nothing to measure super.onMeasure(widthMeasureSpec, heightMeasureSpec); return; } else { if (scaleToWidth) { int iw = imageWidth; int ih = imageHeight; int heightC = width * ih / iw; if (height > 0) if (heightC > height) { // dont let hegiht be greater then set max heightC = height; width = heightC * iw / ih; } this.setScaleType(ScaleType.CENTER_CROP); setMeasuredDimension(width, heightC); } else { // need to scale to height instead int marg = 0; if (getParent() != null) { if (getParent().getParent() != null) { marg += ((RelativeLayout) getParent().getParent()).getPaddingTop(); marg += ((RelativeLayout) getParent().getParent()).getPaddingBottom(); } } int iw = imageWidth; int ih = imageHeight; width = height * iw / ih; height -= marg; setMeasuredDimension(width, height); } } } }