Android 如何在listview中缓存imageview？
我和这家伙有同样的问题 我看到了我必须缓存它的解决方案。但是在我的缓存中，我不确定如何应用解决方案中给出的缓存。我一直收到错误 我怀疑这是我遇到的问题：Android 如何在listview中缓存imageview？,android,listview,caching,bitmap,imageview,Android,Listview,Caching,Bitmap,Imageview,我和这家伙有同样的问题 我看到了我必须缓存它的解决方案。但是在我的缓存中，我不确定如何应用解决方案中给出的缓存。我一直收到错误 我怀疑这是我遇到的问题： holder.icon.setImageBitmap(bitmapList[position]); //loadImageBitmap(mObjects.get(position), position); //onBitmapLoaded(position, holder.mTask.myB
holder.icon.setImageBitmap(bitmapList[position]);
//loadImageBitmap(mObjects.get(position), position);
//onBitmapLoaded(position, holder.mTask.myBitmap());
private static final String TAG = "Adapter";
private Activity mActivity;
public ArrayList<Data> mObjects;
static class ViewHolder {
ImageView icon;
TextView title;
WebView newimage;
DownloadImageTask mTask;
public void setOnClickListener(OnItemClickListener onItemClickListener) {
// TODO Auto-generated method stub
}
}
private Bitmap[] bitmapList;
private Bitmap bitmapPlaceholder;
private void initBitmapListWithPlaceholders(){
// call this whenever the list size changes
// you can also use a list or a map or whatever so you
// don't need to drop all the previously loaded bitmap whenever
// the list contents are modified
int count = getCount();
bitmapList = new Bitmap[count];
for(int i=0;i<count;i++){
bitmapList[i]=bitmapPlaceholder;
}
}
private void onBitmapLoaded(int position, Bitmap bmp){
// this is your callback when the load async is done
bitmapList[position] = bmp;
}
public Adapter(Activity activity, ArrayList<Data> mObjects) {
this.mActivity = (Activity) activity;
this.mObjects = mObjects;
}
public void setObjects(ArrayList<Data> mObjects) {
this.mObjects = mObjects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Data item = mObjects.get(position);
View rowView = convertView;
if (rowView == null) {
LayoutInflater inflater = mActivity.getLayoutInflater();
rowView = inflater.inflate(R.layout.item, parent, false);
ViewHolder viewHolder = new ViewHolder();
viewHolder.icon = (ImageView) rowView.findViewById(R.id.image);
viewHolder.title = (TextView) rowView.findViewById(R.id.title);
viewHolder.newimage =(WebView)rowView.findViewById(R.id.newimage);
rowView.setTag(viewHolder);
}
ViewHolder holder = (ViewHolder) rowView.getTag();
holder.title.setText(item.getmTitle());
//String html = " <html><head></head><body><p font-size='8px'>" + item.getmImageUrl() + "</p><img src='" + item.getmImageUrl() + "' width='100%' height='100%'></body></html>";
String html = " <html><head></head><body><img src='" + item.getmImageUrl() + "' width='100%' height='100%'></body></html>";
holder.newimage.loadData(html, "text/html", "utf-8");
holder.newimage.setFocusable(false);
holder.newimage.setClickable(false);
holder.setOnClickListener(new OnItemClickListener() {
private Object title;
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
//Toast.makeText(Adapter.this,"Button is clicked", Toast.LENGTH_LONG).show();
Log.e("log_tag",this.title.toString() + " clicked");
}
});
//holder.icon.setBackgroundResource(R.drawable.ic_launcher);
holder.mTask = new DownloadImageTask(item.getmImageUrl(), holder.icon);
holder.icon.setImageBitmap(bitmapList[position]);
//loadImageBitmap(mObjects.get(position), position);
//onBitmapLoaded(position, holder.mTask.myBitmap());
if (!holder.mTask.isCancelled()) {
holder.mTask.execute();
}
return rowView;
}
@Override
public int getCount() {
return (this.mObjects.size());
}
@Override
public Object getItem(int position) {
return (this.mObjects.get(position));
}
@Override
public long getItemId(int position) {
return (position);
}
public AbsListView.RecyclerListener mRecyclerListener = new RecyclerListener( ){
public void onMovedToScrapHeap(View view) {
ViewHolder viewHolder = (ViewHolder) view.getTag();
DownloadImageTask imagetask = viewHolder.mTask;
if (imagetask != null) {
imagetask.cancel(true);
}
}
};
public void setOnClickListener(OnItemClickListener onItemClickListener) {
// TODO Auto-generated method stub
}
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.view.View;
import android.widget.ImageView;
public class DownloadImageTask extends AsyncTask<Void, Void, Bitmap> {
public Bitmap g;
private String mUrl;
private ImageView mImageView = null;
public DownloadImageTask(String Url, ImageView imageView) {
mUrl = Url;
this.mImageView = imageView;
}
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
/*
if (result != null) {
mImageView.setImageBitmap(result);
}
*/
if (!(this.mImageView.getTag().toString()).equals(this.mUrl)) {
/* The path is not same. This means that this
image view is handled by some other async task.
We don't do anything and return. */
return;
}
if(result != null && mImageView != null){
mImageView.setVisibility(View.VISIBLE);
mImageView.setImageBitmap(result);
mImageView.setTag(this.mUrl);
}else{
mImageView.setVisibility(View.GONE);
}
}
protected Bitmap doInBackground(Void... params) {
Bitmap bitmap = getBitmap(mUrl);
return bitmap;
}
public Bitmap getBitmap(String imageUrl) {
Bitmap mBitmap = null;
try {
/*URL newurl = new URL(imageUrl);
mBitmap = BitmapFactory.decodeStream(newurl.openConnection() .getInputStream()); */
//mImageView.setImageBitmap(mBitmap);
/*
URL url = new URL(imageUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
InputStream is = conn.getInputStream();
mBitmap = BitmapFactory.decodeStream(new FlushedInputStream(is));*/
InputStream in = new java.net.URL(imageUrl).openStream();
mBitmap = BitmapFactory.decodeStream(new FlushedInputStream (in));
//this.mImageView.setTag(this.mUrl);
//mBitmap.recycle();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
this.g = mBitmap;
return mBitmap;
}
public Bitmap myBitmap() {
Bitmap fg;
fg = (Bitmap) g;
return fg;
}
static class FlushedInputStream extends FilterInputStream {
public FlushedInputStream(InputStream inputStream) {
super(inputStream);
}
@Override
public long skip(long n) throws IOException {
long totalBytesSkipped = 0L;
while (totalBytesSkipped < n) {
long bytesSkipped = in.skip(n - totalBytesSkipped);
if (bytesSkipped == 0L) {
int b = read();
if (b < 0) {
break; // we reached EOF
} else {
bytesSkipped = 1; // we read one byte
}
}
totalBytesSkipped += bytesSkipped;
}
return totalBytesSkipped;
}
}
}
导入java.io.FilterInputStream；
导入java.io.IOException；
导入java.io.InputStream；
导入java.net.MalformedURLException；
导入android.graphics.Bitmap；
导入android.graphics.BitmapFactory；
导入android.os.AsyncTask；
导入android.view.view；
导入android.widget.ImageView；
公共类DownloadImageTask扩展了AsyncTask{
公共图书馆；
私人字符串mUrl；
私有图像视图mImageView=null；
公共下载ImageTask（字符串Url，ImageView ImageView）{
mUrl=Url；
this.mImageView=imageView；
}
受保护的void onPostExecute（位图结果）{
super.onPostExecute（结果）；
/*
如果（结果！=null）{
设置图像位图（结果）；
}
*/
如果（！（this.mImageView.getTag（）.toString（））.equals（this.mUrl））{
/*路径不同。这意味着
图像视图由其他异步任务处理。
我们什么都不做就回来*/
返回；
}
if（结果！=null&&mImageView！=null）{
mImageView.setVisibility（View.VISIBLE）；
设置图像位图（结果）；
setTag（this.mUrl）；
}否则{
mImageView.setVisibility（View.GONE）；
}
}
受保护位图doInBackground（无效…参数）{
位图位图=获取位图（mUrl）；
返回位图；
}
公共位图getBitmap（字符串imageUrl）{
位图mBitmap=null；
试一试{
/*URL newurl=新URL（imageUrl）；
mBitmap=BitmapFactory.decodeStream（newurl.openConnection（）.getInputStream（））*/
//设置图像位图（mBitmap）；
/*
URL URL=新URL（imageUrl）；
HttpURLConnection conn=（HttpURLConnection）url.openConnection（）；
InputStream is=conn.getInputStream（）；
mBitmap=BitmapFactory.decodeStream（新的FlushedInputStream（is））*/
InputStream in=newjava.net.URL（imageUrl.openStream（）；
mBitmap=BitmapFactory.decodeStream（新FlushedInputStream（in））；
//this.mImageView.setTag（this.mUrl）；
//mBitmap.recycle（）；
}捕获（格式错误）{
e、 printStackTrace（）；
}捕获（IOE异常）{
e、 printStackTrace（）；
}
这个.g=mBitmap；
返回mBitmap；
}
公共位图myBitmap（）{
位图fg；
fg=（位图）g；
返回fg；
}
静态类FlushedInputStream扩展FilterInputStream{
公共FlushedInputStream（InputStream InputStream）{
超级（输入流）；
}
@凌驾
公共长跳过（长n）引发IOException{
长的总重量=0升；
while（totalBytesSkippedAsyncTaskgetViewAQuery _aq = new AQuery(mActivity);
_aq.id(R.id.icon).image("IMAGE_URI_TO_LOAD");
holder.icon.setImageBitmap（位图列表[position]）；有关如何使用此库加载图像的详细信息，请查看此处：Hi all…虽然我收到了1个响应，但我需要的是我正在做的事情。仍然无法解决我的问题。McContext中有一个错误。我替换为“this”、“Adapter.this”、“Adapter.java”，但仍然存在问题…我已编辑答案是。尝试使用mActivity而不是McContextNot。我不知道…@_;@顺便说一句，我在DownloadImageTask.java上更新了我的帖子。我无法让它工作。无法调用AQuery。新的AQuery（mActivity）。你已经将AQuery库导入到你的项目中了吗？（通过将AQuery jar文件添加到项目的libs文件夹中）
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.view.View;
import android.widget.ImageView;
public class DownloadImageTask extends AsyncTask<Void, Void, Bitmap> {
public Bitmap g;
private String mUrl;
private ImageView mImageView = null;
public DownloadImageTask(String Url, ImageView imageView) {
mUrl = Url;
this.mImageView = imageView;
}
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
/*
if (result != null) {
mImageView.setImageBitmap(result);
}
*/
if (!(this.mImageView.getTag().toString()).equals(this.mUrl)) {
/* The path is not same. This means that this
image view is handled by some other async task.
We don't do anything and return. */
return;
}
if(result != null && mImageView != null){
mImageView.setVisibility(View.VISIBLE);
mImageView.setImageBitmap(result);
mImageView.setTag(this.mUrl);
}else{
mImageView.setVisibility(View.GONE);
}
}
protected Bitmap doInBackground(Void... params) {
Bitmap bitmap = getBitmap(mUrl);
return bitmap;
}
public Bitmap getBitmap(String imageUrl) {
Bitmap mBitmap = null;
try {
/*URL newurl = new URL(imageUrl);
mBitmap = BitmapFactory.decodeStream(newurl.openConnection() .getInputStream()); */
//mImageView.setImageBitmap(mBitmap);
/*
URL url = new URL(imageUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
InputStream is = conn.getInputStream();
mBitmap = BitmapFactory.decodeStream(new FlushedInputStream(is));*/
InputStream in = new java.net.URL(imageUrl).openStream();
mBitmap = BitmapFactory.decodeStream(new FlushedInputStream (in));
//this.mImageView.setTag(this.mUrl);
//mBitmap.recycle();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
this.g = mBitmap;
return mBitmap;
}
public Bitmap myBitmap() {
Bitmap fg;
fg = (Bitmap) g;
return fg;
}
static class FlushedInputStream extends FilterInputStream {
public FlushedInputStream(InputStream inputStream) {
super(inputStream);
}
@Override
public long skip(long n) throws IOException {
long totalBytesSkipped = 0L;
while (totalBytesSkipped < n) {
long bytesSkipped = in.skip(n - totalBytesSkipped);
if (bytesSkipped == 0L) {
int b = read();
if (b < 0) {
break; // we reached EOF
} else {
bytesSkipped = 1; // we read one byte
}
}
totalBytesSkipped += bytesSkipped;
}
return totalBytesSkipped;
}
}
}
AQuery _aq = new AQuery(mActivity);
_aq.id(R.id.icon).image("IMAGE_URI_TO_LOAD");