我用图片网址获取了json数据。现在我想从json数据中获取该图像URL的图像。那么，我如何从该图像网址获取图像？有什么建议吗？
我从json获得了以下图片网址。
[{....,"image":"xyz.net/abc/img/p/9/0/9/7/9097-tonytheme_product.jpg",....},{....}]
我想在动态创建的imageview上显示上面的图片网址。 我有以下方法用于动态创建的imageview。
public void addImagesToView() {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
Log.i("ArrayList In Image","" +arraylist);
for (int i = 0; i < arraylist.size(); i++) {
imageButton = new ImageView(this);
LinearLayout.LayoutParams params = new LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
// for setting image margin and spacing(left,top,right,bottom)
params.setMargins(60, 20, 5, 5);
imageButton.setLayoutParams(params);
horizontalOuterLayouthome.addView(imageButton);
// horizontalOuterLayouthome.setVisibility(View.INVISIBLE);
}
}
答案 0 :(得分：4)
试试这个..
for (int i = 0; i < arraylist.size(); i++) {
imageButton = new ImageView(this);
Bitmap bitmap = loadImage(arraylist.get(i));
imageButton.setImageBitmap(bitmap);
LinearLayout.LayoutParams params = new LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
// for setting image margin and spacing(left,top,right,bottom)
params.setMargins(60, 20, 5, 5);
imageButton.setLayoutParams(params);
horizontalOuterLayouthome.addView(imageButton);
// horizontalOuterLayouthome.setVisibility(View.INVISIBLE);
}
loadImage 功能
protected Bitmap loadImage(String utl2) {
// TODO Auto-generated method stub
Log.v("utl2--", utl2);
URL imageURL = null;
Bitmap bitmap = null;
try {
imageURL = new URL(utl2);
}
catch (MalformedURLException e) {
e.printStackTrace();
}
try {
HttpURLConnection connection = (HttpURLConnection) imageURL
.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream inputStream = connection.getInputStream();
bitmap = BitmapFactory.decodeStream(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
return bitmap;
}
答案 1 :(得分：1)
试试这段代码：
public static Bitmap loadBitmap(String url) {
Bitmap bitmap = null;
InputStream in = null;
BufferedOutputStream out = null;
try {
in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE);
final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
copy(in, out);
out.flush();
final byte[] data = dataStream.toByteArray();
BitmapFactory.Options options = new BitmapFactory.Options();
//options.inSampleSize = 1;
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,options);
} catch (IOException e) {
Log.e(TAG, "Could not load Bitmap from: " + url);
} finally {
closeStream(in);
closeStream(out);
}
return bitmap;
}
答案 2 :(得分：1)
使用下面的图像加载器类代码和图像适配器.....
public class ImageLoader {
int image_size = 60;
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
Context m_c;
boolean mFlag = false;
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(2);
m_c=context;
}
// final int stub_id = R.drawable.animation_loding;
public void DisplayImage(String url,Bitmap my_bmp, ImageView imageView, int ad_b_width, boolean b)
{
this.mFlag = b;
this.image_size = ad_b_width;
if(url!=null)
{
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null)
{
if(mFlag)
{
int h = bitmap.getHeight();
int w = bitmap.getWidth();
int w1 = image_size;
if(w > w1)
{
int h1 = (h*w1)/w;
System.out.println("photos size :: "+w1 +" and "+h1);
//Bitmap bit = drawShadow(bitmap, 0, 1, 1, 1);
imageView.setLayoutParams(new LinearLayout.LayoutParams(w1, h1));
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageBitmap(bitmap);
}
else
{
imageView.setLayoutParams(new LinearLayout.LayoutParams(w, h));
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageBitmap(bitmap);
}
}
else
{
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageBitmap(bitmap);
}
}
else
{
queuePhoto(url, imageView);
imageView.setScaleType(ScaleType.CENTER);
imageView.setBackgroundResource(R.drawable.region_images);
}
}
else if (my_bmp != null)
{
Bitmap bitmap=my_bmp;
if (bitmap != null)
{
if(mFlag)
{
int h = bitmap.getHeight();
int w = bitmap.getWidth();
int w1 = image_size;
if(w > w1)
{
int h1 = (h*w1)/w;
System.out.println("photos size :: "+w1 +" and "+h1);
//Bitmap bit = drawShadow(bitmap, 0, 1, 1, 1);
imageView.setLayoutParams(new LinearLayout.LayoutParams(w1, h1));
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageBitmap(bitmap);
}
else
{
imageView.setLayoutParams(new LinearLayout.LayoutParams(w, h));
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageBitmap(bitmap);
}
}
else
{
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageBitmap(bitmap);
}
}
}
}
private void queuePhoto(String url, ImageView imageView)
{
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try
{
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex) {
ex.printStackTrace();
return null;
}
}
// 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;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = this.image_size;
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;
Log.i("images scal ", String.valueOf(scale));
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable
{
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad)
{
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
Activity a = (Activity) photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run()
{
if (imageViewReused(photoToLoad))
return;
if (bitmap != null)
{
if(mFlag)
{
int h = bitmap.getHeight();
int w = bitmap.getWidth();
int w1 = image_size;
if(w > w1)
{
int h1 = (h*w1)/w;
System.out.println("photos size :: "+w1 +" and "+h1);
photoToLoad.imageView.setLayoutParams(new LinearLayout.LayoutParams(w1, h1));
photoToLoad.imageView.setScaleType(ScaleType.FIT_XY);
photoToLoad.imageView.setImageBitmap(bitmap);
}
else
{
photoToLoad.imageView.setLayoutParams(new LinearLayout.LayoutParams(w, h));
photoToLoad.imageView.setScaleType(ScaleType.FIT_XY);
photoToLoad.imageView.setImageBitmap(bitmap);
}
bitmap = null;
}
else
{
photoToLoad.imageView.setScaleType(ScaleType.FIT_XY);
photoToLoad.imageView.setImageBitmap(bitmap);
bitmap = null;
}
}
else
{
}
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
答案 3 :(得分：1)
使用Universal Image Loader可以很好地显示和缓存图像https://github.com/nostra13/Android-Universal-Image-Loader
File cacheDir = StorageUtils.getOwnCacheDirectory(a, "your folder");
// Get singletone instance of ImageLoader
imageLoader = ImageLoader.getInstance();
// Create configuration for ImageLoader (all options are optional)
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(a)
// You can pass your own memory cache implementation
.discCache(new UnlimitedDiscCache(cacheDir)) // You can pass your own disc cache implementation
.discCacheFileNameGenerator(new HashCodeFileNameGenerator())
.enableLogging()
.build();
// Initialize ImageLoader with created configuration. Do it once.
imageLoader.init(config);
options = new DisplayImageOptions.Builder()
.showStubImage(R.drawable.stub_id)//display stub image
.cacheInMemory()
.cacheOnDisc()
.displayer(new RoundedBitmapDisplayer(20))
.build();
ImageView image=(ImageView)vi.findViewById(R.id.imageview);
imageLoader.displayImage(imageurl, image,options);
答案 4 :(得分：0)
正如Rich说picasso是一个很好的选择，如果你从JSon收到网址，它会在后台异步任务中非常快速地加载图像，例如：
String imageUrl = "xyz.net/abc/img/p/9/0/9/7/9097-tonytheme_product.jpg"; // this is an example, you can get this url from json
Picasso.with(this.getActivity()).load(imageUrl).into(imageView);
就是这样。