嗨，我找不到一种方法来加载异步模式的联系人图片，我的代码似乎在高端手机上没问题，但内存和处理器较少的手机很慢这是我的代码在我的活动，我使用onScrollchanged避免检索联系人图片上的滚动
mAdapter = new DialerContactsAdapter(contactos,getActivity());
listaContactos.setAdapter(mAdapter);
listaContactos.setFastScrollEnabled(true);
listaContactos.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
switch (scrollState) {
case OnScrollListener.SCROLL_STATE_IDLE:
mAdapter.mBusy = false;
mAdapter.notifyDataSetChanged();
break;
case OnScrollListener.SCROLL_STATE_TOUCH_SCROLL:
mAdapter.mBusy = false;
mAdapter.notifyDataSetChanged();
break;
case OnScrollListener.SCROLL_STATE_FLING:
mAdapter.mBusy = true;
break;
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
}
});
这是我的自定义适配器，我总是从数据库加载图像，我做大小调整，我保存到LruCache类
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder =null;
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.dialer_contact_list, null);
holder = new ViewHolder();
holder.Picture = (ImageView) v.findViewById(R.id.imgContactDialer);
holder.Desc =(TextView) v.findViewById(R.id.txtContactNameDialer);
holder.phone =(TextView)v.findViewById(R.id.txtContactNumberDialer);
v.setTag(holder);
}else
{
holder = (ViewHolder)v.getTag();
}
final ViewHolder holder2 = holder;
final ContactInfo ci = (ContactInfo) getItem(position);
holder2.Picture.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent contact = new Intent(context, ShowSingleContactFragment.class);
contact.putExtra("id", ci.get_id());
contact.putExtra("name", ci.getDisplayName());
context.startActivity(contact);
}
});
//genera PlaceHolder
Bitmap cacheImg = cache.getBitmapFromMemCache(ci.get_id());
if(cacheImg==null)
{
if(!mBusy)
{
new Thread(new Runnable() {
public void run() {
final Bitmap photo= Contacts.loadContactPhoto(ci.get_id(),context.getBaseContext(),context.getResources().getInteger(R.integer.contact_picture_size));
cache.addBitmapToMemoryCache(ci.get_id(), photo);
holder2.Picture.post(new Runnable() {
public void run() {
holder2.Picture.setImageBitmap(photo);
}
});
}
}).start();
}else
{
holder.Picture.setImageResource(R.drawable.ic_contact_picture);
}
}else
{
holder2.Picture.setImageBitmap(cacheImg);
}
}
这是我的BitmapCache类
public class BitmapCache {
public LruCache<String, Bitmap> mMemoryCache;
public BitmapCache(Context mContext)
{
final int memClass = ((ActivityManager) mContext.getSystemService(
Context.ACTIVITY_SERVICE)).getMemoryClass();
// Use 1/8th of the available memory for this memory cache.
final int cacheSize = 1024 * 1024 * memClass / 8;
mMemoryCache = new LruCache <String, Bitmap>(cacheSize) {
@Override
protected int sizeOf(String key, Bitmap bitmap) {
// The cache size will be measured in bytes rather than number of items.
return getByteCount(bitmap);
}
};
}
@SuppressLint("NewApi")
private int getByteCount(Bitmap bitmap)
{
if(Utils.isHoneyComb())
{
return bitmap.getByteCount();
}else
{
return bitmap.getRowBytes() * bitmap.getHeight();
}
}
public void addBitmapToMemoryCache(String key, Bitmap bitmap) {
if (getBitmapFromMemCache(key) == null) {
mMemoryCache.put(key, bitmap);
}
}
public Bitmap getBitmapFromMemCache(String key) {
return mMemoryCache.get(key);
}
}
我找不到库存android联系人列表，有人能帮我吗?非常感谢。
正如@Janmejoy所说，懒惰加载器是更好的选择，至少我是这样认为的。因为几周前我也遇到了同样的问题。我使用了Lazy loader和ViewHolder。首先，我在加载小图像时没有遇到任何问题。然而，我发现较大的图像似乎没有正确缩放，并且显示得很糟糕。然后我对Lazy loader做了一些改变，这样它就可以正确地缩放图像。我的缩放代码是基于这个
在ImageLoader类中，我定义了一个变量DisplayMetrics disMetrics;，并在构造函数中这样做:disMetrics = new DisplayMetrics();
下一步是对decodeFile(File file)方法进行一些修改:
//decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f){
try {
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1=new FileInputStream(f);
BitmapFactory.decodeStream(stream1,null,o);
stream1.close();
// my custom scaling
int tw = disMetrics.widthPixels;
int th = disMetrics.heightPixels;
int targetWidth = tw <= 0 ? Integer.MAX_VALUE : tw;
int targetHeight = th <= 0 ? Integer.MAX_VALUE : th;
int scale = 0;
while ((o.outWidth >> scale) > targetWidth || (o.outHeight >> scale) > targetHeight) {
scale++;
}
// native scaling
//Find the correct scale value. It should be the power of 2.
//final int REQUIRED_SIZE=70;
//int width_tmp=o.outWidth, height_tmp=o.outHeight;
//int scale=1;
//while(true){
// if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
// break;
// width_tmp/=2;
// height_tmp/=2;
// scale*=2;
//}
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
o2.inSampleSize = 1 << scale;
FileInputStream stream2=new FileInputStream(f);
Bitmap bitmap=BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
}
catch (IOException e) {
e.printStackTrace();
}
return null;
}
欢呼。