我试图在gridview中获取图像和文本。
从Web服务检索这些数据。我检索了相同但不知道如何在gridview中设置这些数据！
答案 0 :(得分：0)
您可以使用以下命令在gridview
的同一单元格上显示图像视图和textview创建一个viewHolder类并编辑适配器的getView()，如下所示
public static class ViewHolder {
public TextView text;
public ImageView image;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View vi;
ViewHolder holder;
if (convertView == null) {
vi = new View(activity);
LayoutInflater inflater = activity.getLayoutInflater();
vi = inflater.inflate(R.layout.item, null, true);
holder = new ViewHolder();
holder.text = (TextView) vi.findViewById(R.id.text);
holder.image = (ImageView) vi.findViewById(R.id.image);
vi.setTag(holder);
} else {
vi = convertView;
holder = (ViewHolder) vi.getTag();
holder.text.setText(CategoryList.get(position).toString());
holder.image.setImageDrawable(drawable);
holder.image.setTag(R.drawable.arrow);
}
holder.text.setText(CategoryList.get(position).toString());
holder.image.setTag(R.drawable.arrow);
vi.setTag(holder);
return vi;
}
编辑：
我也有同样的问题我从webservices获取图像网址，我想在listview上显示图像：所以我使用以下类在SD卡上使用hashset保存图像
public class CacheImages {
private HashMap<String, Bitmap> cache = new HashMap<String, Bitmap>();
private File cacheDir;
final int stub_id = your.package.name.R.drawable.stub;
PhotosQueue photosQueue = new PhotosQueue();
PhotosLoader photoLoaderThread = new PhotosLoader();
CacheImages(Context context) {
// Make the background thead low priority. This way it will not affect
// the UI performance
photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
// Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)) {
cacheDir = new File(
android.os.Environment.getExternalStorageDirectory(),
"/data/projectname");
//Log.v("cacheDir ", cacheDir + "");
} else {
cacheDir = context.getCacheDir();
}
if (!cacheDir.exists())
cacheDir.mkdirs();
}
// 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 extends Thread {
public void run() {
try {
while (true) {
// thread waits until there are any images to load in the
// queue
if (photosQueue.photosToLoad.size() == 0)
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.wait();
}
//else{
if (photosQueue.photosToLoad.size() != 0) {
PhotoToLoad photoToLoad;
synchronized (photosQueue.photosToLoad) {
photoToLoad = photosQueue.photosToLoad.pop();
}
Bitmap bmp = getBitmap(photoToLoad.url);
cache.put(photoToLoad.url, bmp);
if ((photoToLoad.imageView.getTag())
.equals(photoToLoad.url)) {
BitmapDisplayer bd = new BitmapDisplayer(bmp,
photoToLoad.imageView);
Activity a = (Activity) photoToLoad.imageView
.getContext();
a.runOnUiThread(bd);
}
}
//}
if (Thread.interrupted())
break;
}
} catch (InterruptedException e) {
// allow thread to exit
}
}
}
private Bitmap getBitmap(String url) {
// PhotoToLoad photoToLoad = new PhotoToLoad(url, new ImageView(a));
// String filename = photoToLoad.url;
//String filename = url;
String filename = String.valueOf(url.hashCode());
//Log.v("TAG FILE :", filename);
File f = new File(cacheDir, filename);
// Is the bitmap in our cache?
Bitmap bitmap = BitmapFactory.decodeFile(f.getPath());
if (bitmap != null)
return bitmap;
else {
// Nope, have to download it
try {
bitmap = BitmapFactory.decodeStream(new URL(url)
.openConnection().getInputStream());
// save bitmap to cache for later
writeFile(bitmap, f);
return bitmap;
} catch (FileNotFoundException ex) {
ex.printStackTrace();
//Log.v("FILE NOT FOUND", "FILE NOT FOUND");
return null;
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
return null;
}
}
}
private void writeFile(Bitmap bmp, File f) {
FileOutputStream out = null;
try {
out = new FileOutputStream(f);
bmp.compress(Bitmap.CompressFormat.PNG, 80, out);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (out != null)
out.close();
} catch (Exception ex) {
}
}
}
public void DisplayImage(String url, Activity activity, ImageView imageView) {
if (cache.containsKey(url))
imageView.setImageBitmap(cache.get(url));
else {
queuePhoto(url, activity, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, Activity activity, ImageView imageView) {
// This ImageView may be used for other images before. So there may be
// some old tasks in the queue. We need to discard them.
photosQueue.Clean(imageView);
PhotoToLoad p = new PhotoToLoad(url, imageView);
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.push(p);
photosQueue.photosToLoad.notifyAll();
}
// start thread if it's not started yet
if (photoLoaderThread.getState() == Thread.State.NEW)
photoLoaderThread.start();
}
// stores list of photos to download
class PhotosQueue {
private Stack<PhotoToLoad> photosToLoad = new Stack<PhotoToLoad>();
// removes all instances of this ImageView
public void Clean(ImageView image) {
for (int j = 0; j < photosToLoad.size();) {
if (photosToLoad.get(j).imageView == image)
photosToLoad.remove(j);
else
++j;
}
}
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
ImageView imageView;
public BitmapDisplayer(Bitmap b, ImageView i) {
bitmap = b;
imageView = i;
}
public void run() {
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else
imageView.setImageResource(stub_id);
}
}
public void clearCache() {
// clear memory cache
cache.clear();
// clear SD cache
File[] files = cacheDir.listFiles();
for (File f : files)
f.delete();
}
}
然后从url加载图像我使用下面的代码在listitem上显示图像
holder.image.setTag(img.getImage(holder.image, Url));