我有一个URL中的两个图像到我的图库视图中。但是当我去另一个活动时，图像会再次从在线重新加载。我想为每个应用程序实例请求一次。我将如何保存这个状态？
/** Simple Constructor saving the 'parent' context. */
public ImageAdapter(Context c) { this.myContext = c; }
/** Returns the amount of images we have defined. */
public int getCount() { return this.myRemoteImages.length; }
/* Use the array-Positions as unique IDs */
public Object getItem(int position) { return position; }
public long getItemId(int position) { return position; }
/** Returns a new ImageView to
* be displayed, depending on
* the position passed. */
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(this.myContext);
try {
/* Open a new URL and get the InputStream to load data from it. */
URL aURL = new URL(myRemoteImages[position]);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
/* Buffered is always good for a performance plus. */
BufferedInputStream bis = new BufferedInputStream(is);
/* Decode url-data to a bitmap. */
Bitmap bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
/* Apply the Bitmap to the ImageView that will be returned. */
i.setImageBitmap(bm);
} catch (IOException e) {
Log.e("DEBUGTAG", "Remtoe Image Exception", e);
}
/* Image should be scaled as width/height are set. */
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
/* Set the Width/Height of the ImageView. */
i.setLayoutParams(new Gallery.LayoutParams(150, 150));
return i;
}
/** Returns the size (0.0f to 1.0f) of the views
* depending on the 'offset' to the center. */
public float getScale(boolean focused, int offset) {
/* Formula: 1 / (2 ^ offset) */
return Math.max(0, 1.0f / (float)Math.pow(2, Math.abs(offset)));
}
}
public class ImageAdapter2 extends BaseAdapter {
/** The parent context */
private Context myContext;public ImageAdapter2() {
// TODO Auto-generated constructor stub
}
/** URL-Strings to some remote images. */
private String[] myRemoteImages = {imageUrl2};
/** Simple Constructor saving the 'parent' context. */
public ImageAdapter2(Context c) { this.myContext = c; }
/** Returns the amount of images we have defined. */
public int getCount() { return this.myRemoteImages.length; }
/* Use the array-Positions as unique IDs */
public Object getItem(int position) { return position; }
public long getItemId(int position) { return position; }
/** Returns a new ImageView to
* be displayed, depending on
* the position passed. */
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(this.myContext);
try {
/* Open a new URL and get the InputStream to load data from it. */
URL aURL = new URL(myRemoteImages[position]);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
/* Buffered is always good for a performance plus. */
BufferedInputStream bis = new BufferedInputStream(is);
/* Decode url-data to a bitmap. */
Bitmap bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
/* Apply the Bitmap to the ImageView that will be returned. */
i.setImageBitmap(bm);
} catch (IOException e) {
Log.e("DEBUGTAG", "Remtoe Image Exception", e);
}
/* Image should be scaled as width/height are set. */
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
/* Set the Width/Height of the ImageView. */
i.setLayoutParams(new Gallery.LayoutParams(150, 150));
return i;
}
/** Returns the size (0.0f to 1.0f) of the views
* depending on the 'offset' to the center. */
public float getScale(boolean focused, int offset) {
/* Formula: 1 / (2 ^ offset) */
return Math.max(0, 1.0f / (float)Math.pow(2, Math.abs(offset)));
}
}
答案 0 :(得分：0)
您可以将图像保存为静态图像，也可以将它们放在HashMap中（键是URL，值是图像位图）供以后使用，或者您可以进行图像的延迟下载，或者最后可以使用Application类（参见{ {3}}保持全局状态）但是存储图像并不好（通常会产生内存问题），每次使用延迟加载时都要下载它们。