使用android查询从服务器html源加载图像
我有一个带有img标签的html内容字符串。对于我使用的图像URL：使用android查询从服务器html源加载图像,android,android-query,Android,Android Query,我有一个带有img标签的html内容字符串。对于我使用的图像URL： Spanned htmlSpan = Html.fromHtml(item.message, imgGetter, null); descriptionView.setText(htmlSpan); ImageGetter必须实现方法getDrawable，该方法应返回Drawable对象 Html.ImageGetter imgGetter = new Html.ImageGetter() { public Dra
Spanned htmlSpan = Html.fromHtml(item.message, imgGetter, null);
descriptionView.setText(htmlSpan);
getDrawableHtml.ImageGetter imgGetter = new Html.ImageGetter() {
public Drawable getDrawable(String source) {
aq.ajax(Cfg.SITE_URL+source, Drawable.class, new AjaxCallback<Drawable> (){
@Override
public void callback(String url, Drawable d, AjaxStatus status) {
//Something here
}
});
return result; // nothing for result now
}
};
Html.ImageGetter imgGetter=new Html.ImageGetter（）{
公共可绘制getDrawable（字符串源）{
ajax（Cfg.SITE\uURL+source，Drawable.class，新的AjaxCallback（）{
@凌驾
公共void回调（字符串url、可绘制d、AjaxStatus状态）{
//这里有东西
}
});
返回结果；//现在结果为空
}
};
UPD:aq是
aq=新水室（此）使用通用图像加载器下载所有图像您需要安卓查询吗？我认为这不是最好的方法。
实际上，有很多库可以做到这一点，比如
或
但是，如果您想有一个更简单的代码，您可以使用这个示例表单
这是哪个主要代码
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.imagedownloader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.net.http.AndroidHttpClient;
import android.os.AsyncTask;
import android.os.Handler;
import android.util.Log;
import android.widget.ImageView;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.concurrent.ConcurrentHashMap;
/**
* This helper class download images from the Internet and binds those with the provided ImageView.
*
* <p>It requires the INTERNET permission, which should be added to your application's manifest
* file.</p>
*
* A local cache of downloaded images is maintained internally to improve performance.
*/
public class ImageDownloader {
private static final String LOG_TAG = "ImageDownloader";
public enum Mode { NO_ASYNC_TASK, NO_DOWNLOADED_DRAWABLE, CORRECT }
private Mode mode = Mode.NO_ASYNC_TASK;
/**
* Download the specified image from the Internet and binds it to the provided ImageView. The
* binding is immediate if the image is found in the cache and will be done asynchronously
* otherwise. A null bitmap will be associated to the ImageView if an error occurs.
*
* @param url The URL of the image to download.
* @param imageView The ImageView to bind the downloaded image to.
*/
public void download(String url, ImageView imageView) {
resetPurgeTimer();
Bitmap bitmap = getBitmapFromCache(url);
if (bitmap == null) {
forceDownload(url, imageView);
} else {
cancelPotentialDownload(url, imageView);
imageView.setImageBitmap(bitmap);
}
}
/*
* Same as download but the image is always downloaded and the cache is not used.
* Kept private at the moment as its interest is not clear.
private void forceDownload(String url, ImageView view) {
forceDownload(url, view, null);
}
*/
/**
* Same as download but the image is always downloaded and the cache is not used.
* Kept private at the moment as its interest is not clear.
*/
private void forceDownload(String url, ImageView imageView) {
// State sanity: url is guaranteed to never be null in DownloadedDrawable and cache keys.
if (url == null) {
imageView.setImageDrawable(null);
return;
}
if (cancelPotentialDownload(url, imageView)) {
switch (mode) {
case NO_ASYNC_TASK:
Bitmap bitmap = downloadBitmap(url);
addBitmapToCache(url, bitmap);
imageView.setImageBitmap(bitmap);
break;
case NO_DOWNLOADED_DRAWABLE:
imageView.setMinimumHeight(156);
BitmapDownloaderTask task = new BitmapDownloaderTask(imageView);
task.execute(url);
break;
case CORRECT:
task = new BitmapDownloaderTask(imageView);
DownloadedDrawable downloadedDrawable = new DownloadedDrawable(task);
imageView.setImageDrawable(downloadedDrawable);
imageView.setMinimumHeight(156);
task.execute(url);
break;
}
}
}
/**
* Returns true if the current download has been canceled or if there was no download in
* progress on this image view.
* Returns false if the download in progress deals with the same url. The download is not
* stopped in that case.
*/
private static boolean cancelPotentialDownload(String url, ImageView imageView) {
BitmapDownloaderTask bitmapDownloaderTask = getBitmapDownloaderTask(imageView);
if (bitmapDownloaderTask != null) {
String bitmapUrl = bitmapDownloaderTask.url;
if ((bitmapUrl == null) || (!bitmapUrl.equals(url))) {
bitmapDownloaderTask.cancel(true);
} else {
// The same URL is already being downloaded.
return false;
}
}
return true;
}
/**
* @param imageView Any imageView
* @return Retrieve the currently active download task (if any) associated with this imageView.
* null if there is no such task.
*/
private static BitmapDownloaderTask getBitmapDownloaderTask(ImageView imageView) {
if (imageView != null) {
Drawable drawable = imageView.getDrawable();
if (drawable instanceof DownloadedDrawable) {
DownloadedDrawable downloadedDrawable = (DownloadedDrawable)drawable;
return downloadedDrawable.getBitmapDownloaderTask();
}
}
return null;
}
Bitmap downloadBitmap(String url) {
final int IO_BUFFER_SIZE = 4 * 1024;
// AndroidHttpClient is not allowed to be used from the main thread
final HttpClient client = (mode == Mode.NO_ASYNC_TASK) ? new DefaultHttpClient() :
AndroidHttpClient.newInstance("Android");
final HttpGet getRequest = new HttpGet(url);
try {
HttpResponse response = client.execute(getRequest);
final int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
Log.w("ImageDownloader", "Error " + statusCode +
" while retrieving bitmap from " + url);
return null;
}
final HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream inputStream = null;
try {
inputStream = entity.getContent();
// return BitmapFactory.decodeStream(inputStream);
// Bug on slow connections, fixed in future release.
return BitmapFactory.decodeStream(new FlushedInputStream(inputStream));
} finally {
if (inputStream != null) {
inputStream.close();
}
entity.consumeContent();
}
}
} catch (IOException e) {
getRequest.abort();
Log.w(LOG_TAG, "I/O error while retrieving bitmap from " + url, e);
} catch (IllegalStateException e) {
getRequest.abort();
Log.w(LOG_TAG, "Incorrect URL: " + url);
} catch (Exception e) {
getRequest.abort();
Log.w(LOG_TAG, "Error while retrieving bitmap from " + url, e);
} finally {
if ((client instanceof AndroidHttpClient)) {
((AndroidHttpClient) client).close();
}
}
return null;
}
/*
* An InputStream that skips the exact number of bytes provided, unless it reaches EOF.
*/
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;
}
}
/**
* The actual AsyncTask that will asynchronously download the image.
*/
class BitmapDownloaderTask extends AsyncTask<String, Void, Bitmap> {
private String url;
private final WeakReference<ImageView> imageViewReference;
public BitmapDownloaderTask(ImageView imageView) {
imageViewReference = new WeakReference<ImageView>(imageView);
}
/**
* Actual download method.
*/
@Override
protected Bitmap doInBackground(String... params) {
url = params[0];
return downloadBitmap(url);
}
/**
* Once the image is downloaded, associates it to the imageView
*/
@Override
protected void onPostExecute(Bitmap bitmap) {
if (isCancelled()) {
bitmap = null;
}
addBitmapToCache(url, bitmap);
if (imageViewReference != null) {
ImageView imageView = imageViewReference.get();
BitmapDownloaderTask bitmapDownloaderTask = getBitmapDownloaderTask(imageView);
// Change bitmap only if this process is still associated with it
// Or if we don't use any bitmap to task association (NO_DOWNLOADED_DRAWABLE mode)
if ((this == bitmapDownloaderTask) || (mode != Mode.CORRECT)) {
imageView.setImageBitmap(bitmap);
}
}
}
}
/**
* A fake Drawable that will be attached to the imageView while the download is in progress.
*
* <p>Contains a reference to the actual download task, so that a download task can be stopped
* if a new binding is required, and makes sure that only the last started download process can
* bind its result, independently of the download finish order.</p>
*/
static class DownloadedDrawable extends ColorDrawable {
private final WeakReference<BitmapDownloaderTask> bitmapDownloaderTaskReference;
public DownloadedDrawable(BitmapDownloaderTask bitmapDownloaderTask) {
super(Color.BLACK);
bitmapDownloaderTaskReference =
new WeakReference<BitmapDownloaderTask>(bitmapDownloaderTask);
}
public BitmapDownloaderTask getBitmapDownloaderTask() {
return bitmapDownloaderTaskReference.get();
}
}
public void setMode(Mode mode) {
this.mode = mode;
clearCache();
}
/*
* Cache-related fields and methods.
*
* We use a hard and a soft cache. A soft reference cache is too aggressively cleared by the
* Garbage Collector.
*/
private static final int HARD_CACHE_CAPACITY = 10;
private static final int DELAY_BEFORE_PURGE = 10 * 1000; // in milliseconds
// Hard cache, with a fixed maximum capacity and a life duration
private final HashMap<String, Bitmap> sHardBitmapCache =
new LinkedHashMap<String, Bitmap>(HARD_CACHE_CAPACITY / 2, 0.75f, true) {
@Override
protected boolean removeEldestEntry(LinkedHashMap.Entry<String, Bitmap> eldest) {
if (size() > HARD_CACHE_CAPACITY) {
// Entries push-out of hard reference cache are transferred to soft reference cache
sSoftBitmapCache.put(eldest.getKey(), new SoftReference<Bitmap>(eldest.getValue()));
return true;
} else
return false;
}
};
// Soft cache for bitmaps kicked out of hard cache
private final static ConcurrentHashMap<String, SoftReference<Bitmap>> sSoftBitmapCache =
new ConcurrentHashMap<String, SoftReference<Bitmap>>(HARD_CACHE_CAPACITY / 2);
private final Handler purgeHandler = new Handler();
private final Runnable purger = new Runnable() {
public void run() {
clearCache();
}
};
/**
* Adds this bitmap to the cache.
* @param bitmap The newly downloaded bitmap.
*/
private void addBitmapToCache(String url, Bitmap bitmap) {
if (bitmap != null) {
synchronized (sHardBitmapCache) {
sHardBitmapCache.put(url, bitmap);
}
}
}
/**
* @param url The URL of the image that will be retrieved from the cache.
* @return The cached bitmap or null if it was not found.
*/
private Bitmap getBitmapFromCache(String url) {
// First try the hard reference cache
synchronized (sHardBitmapCache) {
final Bitmap bitmap = sHardBitmapCache.get(url);
if (bitmap != null) {
// Bitmap found in hard cache
// Move element to first position, so that it is removed last
sHardBitmapCache.remove(url);
sHardBitmapCache.put(url, bitmap);
return bitmap;
}
}
// Then try the soft reference cache
SoftReference<Bitmap> bitmapReference = sSoftBitmapCache.get(url);
if (bitmapReference != null) {
final Bitmap bitmap = bitmapReference.get();
if (bitmap != null) {
// Bitmap found in soft cache
return bitmap;
} else {
// Soft reference has been Garbage Collected
sSoftBitmapCache.remove(url);
}
}
return null;
}
/**
* Clears the image cache used internally to improve performance. Note that for memory
* efficiency reasons, the cache will automatically be cleared after a certain inactivity delay.
*/
public void clearCache() {
sHardBitmapCache.clear();
sSoftBitmapCache.clear();
}
/**
* Allow a new delay before the automatic cache clear is done.
*/
private void resetPurgeTimer() {
purgeHandler.removeCallbacks(purger);
purgeHandler.postDelayed(purger, DELAY_BEFORE_PURGE);
}
}
/*
*版权所有（C）2010安卓开源项目
*
*根据Apache许可证2.0版（以下简称“许可证”）获得许可；
*除非遵守许可证，否则不得使用此文件。
*您可以通过以下方式获得许可证副本：
*
* http://www.apache.org/licenses/LICENSE-2.0
*
*除非适用法律要求或书面同意，软件
*根据许可证进行的分发是按“原样”进行分发的，
*无任何明示或暗示的保证或条件。
*请参阅许可证以了解管理权限和权限的特定语言
*许可证下的限制。
*/
包com.example.android.imagedownloader；
导入org.apache.http.HttpEntity；
导入org.apache.http.HttpResponse；
导入org.apache.http.HttpStatus；
导入org.apache.http.client.HttpClient；
导入org.apache.http.client.methods.HttpGet；
导入org.apache.http.impl.client.DefaultHttpClient；
导入android.graphics.Bitmap；
导入android.graphics.BitmapFactory；
导入android.graphics.Color；
导入android.graphics.drawable.ColorDrawable；
导入android.graphics.drawable.drawable；
导入android.net.http.AndroidHttpClient；
导入android.os.AsyncTask；
导入android.os.Handler；
导入android.util.Log；
导入android.widget.ImageView；
导入java.io.FilterInputStream；
导入java.io.IOException；
导入java.io.InputStream；
导入java.lang.ref.SoftReference；
导入java.lang.ref.WeakReference；
导入java.util.HashMap；
导入java.util.LinkedHashMap；
导入java.util.concurrent.ConcurrentHashMap；
/**
*这个助手类从Internet下载图像，并将这些图像与提供的ImageView绑定。
*
*它需要INTERNET权限，该权限应添加到应用程序的清单中
*文件
*
*下载图像的本地缓存在内部维护，以提高性能。
*/
公共类图像下载程序{
私有静态最终字符串日志\u TAG=“ImageDownloader”；
公共枚举模式{NO_ASYNC_TASK，NO_download_DRAWABLE，CORRECT}
私有模式=模式。无异步任务；
/**
*从Internet下载指定的图像并将其绑定到提供的ImageView
*如果在缓存中找到映像，则绑定是立即的，并且将异步完成
*否则。如果发生错误，则会将空位图关联到ImageView。
*
*@param url要下载的图像的url。
*@param imageView将下载的图像绑定到的imageView。
*/
公共void下载（字符串url，ImageView）{
重置PurgeTimer（）；
位图位图=getBitmapFromCache（url）；
如果（位图==null）{
强制下载（url、imageView）；
}否则{
取消潜在下载（url、imageView）；
设置图像位图（位图）；
}
}
/*
*与下载相同，但始终下载映像，不使用缓存。
*由于利益不明，目前保密。
私有void forceDownload（字符串url、图像视图）{
强制下载（url、视图、空）；
}
*/
/**
*与下载相同，但始终下载映像，不使用缓存。
*由于利益不明，目前保密。
*/
私有void forceDownload（字符串url，ImageView）{
//状态健全性：url在下载的可绘制和缓存密钥中保证永远不为空。
如果（url==null）{
imageView.setImageDrawable（空）；
返回；
}
if（取消潜在下载（url，图像视图））{
开关（模式）{
案例编号异步任务：
位图位图=下载位图（url）；
addBitmapToCache（url、位图）；
设置图像位图（位图）；
打破
案例编号\u下载\u可提取：
imageView.setMinimumHeight（156）；
BitmapDownloaderTask任务=新建BitmapDownloaderTask（图像视图）；
task.execute（url）；
打破
大小写正确：
任务=新位图下载任务（imageView）；
DownloadedDrawable DownloadedDrawable=新的DownloadedDrawable（任务）；
imageView.setImageDrawable（可下载Drawable）；
imageView.setMinimumHeight（156）；
task.execute（url）；
打破
}
}
}
/**
*如果当前下载已取消或中没有下载，则返回true
*此图像视图的进度。
*如果正在进行的下载处理相同的url，则返回false。下载不正确
*在那种情况下停止。
*/
私有静态布尔cancelPotentialDownload（字符串url，ImageView ImageView）{
BitMapDownloader任务BitMapDownloader任务=getBitmapDownloader