我从 AOSP 壁纸选择器中获得了以下代码，我试图将我的壁纸预览图像简单地显示为平板电脑上的 centerCrop 和手机上的 FitXY，仅仅是因为壁纸图像可能不够大，无法填充活动屏幕平板电脑因此我想centerCrop它。
现在我加载我的中心图像的方式是通过我的片段并且我没有特定的 ImageView 我可以简单地在 xml 文件之间进行更改（简单的方法）。我只是在寻找实现这一目标的最佳方法的一些帮助。
这是代码 - （完整代码）
public class WallpaperChooser extends Activity {
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.wallpaper_chooser_base);
Fragment fragmentView = getFragmentManager().findFragmentById(
R.id.wallpaper_chooser_fragment);
if (fragmentView == null) {
DialogFragment fragment = WallpaperChooserDialogFragment
.newInstance();
fragment.show(getFragmentManager(), "dialog");
}
}
public class WallpaperChooserDialogFragment extends DialogFragment implements
AdapterView.OnItemSelectedListener, AdapterView.OnItemClickListener {
private static final String TAG = "MainActivity.WallpaperChooserDialogFragment";
private static final String EMBEDDED_KEY = "org.app.wallpapers."
+ "WallpaperChooserDialogFragment.EMBEDDED_KEY";
private static final String SD = Environment.getExternalStorageDirectory().getAbsolutePath();
private boolean mEmbedded;
private Bitmap mBitmap = null;
private ImageAdapter mAdapter;
private ImageView image;
private ArrayList<Integer> mThumbs;
private ArrayList<Integer> mImages;
private WallpaperLoader mLoader;
private WallpaperDrawable mWallpaperDrawable = new WallpaperDrawable();
public static WallpaperChooserDialogFragment newInstance() {
WallpaperChooserDialogFragment fragment = new WallpaperChooserDialogFragment();
fragment.setCancelable(true);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null && savedInstanceState.containsKey(EMBEDDED_KEY)) {
mEmbedded = savedInstanceState.getBoolean(EMBEDDED_KEY);
} else {
mEmbedded = isInLayout();
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
outState.putBoolean(EMBEDDED_KEY, mEmbedded);
}
private void cancelLoader() {
if (mLoader != null && mLoader.getStatus() != WallpaperLoader.Status.FINISHED) {
mLoader.cancel(true);
mLoader = null;
}
}
@Override
public void onDetach() {
super.onDetach();
cancelLoader();
}
@Override
public void onDestroy() {
super.onDestroy();
cancelLoader();
}
@Override
public void onDismiss(DialogInterface dialog) {
super.onDismiss(dialog);
/* On orientation changes, the dialog is effectively "dismissed" so this is called
* when the activity is no longer associated with this dying dialog fragment. We
* should just safely ignore this case by checking if getActivity() returns null
*/
Activity activity = getActivity();
if (activity != null) {
activity.finish();
}
}
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
findWallpapers();
return null;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
findWallpapers();
if (mEmbedded) {
View view = inflater.inflate(R.layout.wallpaper_chooser, container, false);
view.setBackgroundDrawable(mWallpaperDrawable);
final Gallery gallery = (Gallery) view.findViewById(R.id.gallery);
gallery.setCallbackDuringFling(false);
gallery.setOnItemSelectedListener(this);
//gallery.setAdapter(new ImageAdapter(getActivity()));
mAdapter = new ImageAdapter(getActivity());
gallery.setAdapter(mAdapter);
return view;
}
return null;
}
private void selectWallpaper(int position) {
try {
WallpaperManager wpm = (WallpaperManager) getActivity().getSystemService(
Context.WALLPAPER_SERVICE);
wpm.setResource(mImages.get(position));
Activity activity = getActivity();
activity.setResult(Activity.RESULT_OK);
activity.finish();
} catch (IOException e) {
Log.e(TAG, "Failed to set wallpaper: " + e);
}
}
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectWallpaper(position);
}
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if (mLoader != null && mLoader.getStatus() != WallpaperLoader.Status.FINISHED) {
//image.startAnimation(animFadeOut);
mLoader.cancel();
}
mLoader = (WallpaperLoader) new WallpaperLoader().execute(position);
}
public void onNothingSelected(AdapterView<?> parent) {
}
private void findWallpapers() {
mThumbs = new ArrayList<Integer>(24);
mImages = new ArrayList<Integer>(24);
final Resources resources = getResources();
final String packageName = resources.getResourcePackageName(R.array.all_wallpapers);
addWallpapers(resources, packageName, R.array.all_wallpapers);
}
private void addWallpapers(Resources resources, String packageName, int list) {
final String[] extras = resources.getStringArray(list);
for (String extra : extras) {
int res = resources.getIdentifier(extra, "drawable", packageName);
if (res != 0) {
final int thumbRes = resources.getIdentifier(extra + "_thumb",
"drawable", packageName);
if (thumbRes != 0) {
mThumbs.add(thumbRes);
mImages.add(res);
}
}
}
}
private class ImageAdapter extends BaseAdapter implements ListAdapter, SpinnerAdapter {
private LayoutInflater mLayoutInflater;
ImageAdapter(Activity activity) {
mLayoutInflater = activity.getLayoutInflater();
}
public int getCount() {
return mThumbs.size();
}
public Bitmap getImage(int i)
{
return getBitmap(((Integer)mImages.get(i)).intValue());
}
public Bitmap getItem(int i)
{
return getBitmap(((Integer)mImages.get(i)).intValue());
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
View view;
if (convertView == null) {
view = mLayoutInflater.inflate(R.layout.wallpaper_item, parent, false);
} else {
//image.startAnimation(animFadeIn);
view = convertView;
}
image = (ImageView) view.findViewById(R.id.wallpaper_image);
int thumbRes = mThumbs.get(position);
image.setImageResource(thumbRes);
Drawable thumbDrawable = image.getDrawable();
if (thumbDrawable != null) {
thumbDrawable.setDither(true);
} else {
Log.e(TAG, "Error decoding thumbnail resId=" + thumbRes + " for wallpaper #"
+ position);
}
return view;
}
}
class WallpaperLoader extends AsyncTask<Integer, Void, Bitmap> {
BitmapFactory.Options mOptions;
WallpaperLoader() {
mOptions = new BitmapFactory.Options();
mOptions.inDither = false;
mOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;
}
@Override
protected Bitmap doInBackground(Integer... params) {
if (isCancelled()) return null;
try {
return BitmapFactory.decodeResource(getResources(),
mImages.get(params[0]), mOptions);
} catch (OutOfMemoryError e) {
return null;
}
}
@Override
protected void onPostExecute(Bitmap b) {
if (b == null) return;
if (!isCancelled() && !mOptions.mCancel) {
// Help the GC
if (mBitmap != null) {
mBitmap.recycle();
}
View v = getView();
if (v != null) {
mBitmap = b;
mWallpaperDrawable.setBitmap(b);
v.postInvalidate();
} else {
mBitmap = null;
mWallpaperDrawable.setBitmap(null);
}
mLoader = null;
} else {
b.recycle();
}
}
void cancel() {
mOptions.requestCancelDecode();
super.cancel(true);
}
}
static class WallpaperDrawable extends Drawable {
Bitmap mBitmap;
int mIntrinsicWidth;
int mIntrinsicHeight;
/* package */void setBitmap(Bitmap bitmap) {
mBitmap = bitmap;
if (mBitmap == null)
return;
mIntrinsicWidth = mBitmap.getWidth();
mIntrinsicHeight = mBitmap.getHeight();
}
@Override
public void draw(Canvas canvas) {
if (mBitmap == null) return;
int width = canvas.getWidth();
int height = canvas.getHeight();
int x = (width - mIntrinsicWidth) / 2;
int y = (height - mIntrinsicHeight) / 2;
canvas.drawBitmap(mBitmap, x, y, null);
}
@Override
public int getOpacity() {
return android.graphics.PixelFormat.OPAQUE;
}
}
private Bitmap getBitmap(int i)
{
System.out.println(i);
if(i != 0)
{
System.out.println("ResourceID != 0");
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), i);
PrintStream printstream = System.out;
StringBuilder stringbuilder = new StringBuilder("Bitmap = null = ");
boolean flag;
if(bitmap == null)
flag = true;
else
flag = false;
printstream.println(stringbuilder.append(flag).toString());
if(bitmap != null)
return bitmap;
}
return null;
}