我有一些照片的活动，我正在使用 ViewPager 刷这些照片。如何在活动开始时显示一些透明图像，只是为了显示一些关于滑动和东西的说明，就像 ES File Explorer 在下图中所做的那样？我有和图像，像下面的那样透明。我想在我的第一张图片上显示它，用户可以滑动它。
这是我的课：
public class Photo_gallery extends Activity implements OnClickListener{
Button save;
Context mContext;
final File myDir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/Pictures/Images/");
boolean success = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
mContext = this;
super.onCreate(savedInstanceState);
setContentView(R.layout.photo_gallery);
save = (Button) findViewById(R.id.bSave);
final ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
final ImagePagerAdapter adapter = new ImagePagerAdapter();
viewPager.setAdapter(adapter);
save.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
final Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
final String fname = "StyleMe-" + n + ".png";
myDir.mkdirs();
File image = new File(myDir, fname);
int currentItem = viewPager.getCurrentItem();
Drawable drawable = mContext.getResources().getDrawable(adapter.mImages[currentItem]);
Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
// Encode the file as a PNG image.
FileOutputStream outStream;
try {
outStream = new FileOutputStream(image);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
/* 100 to keep full quality of the image */
outStream.flush();
outStream.close();
success = true;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
if (success) {
Toast.makeText(getApplicationContext(), "Image saved with success at /sdcard/Pictures/SexyImages",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(),
"Error during image saving", Toast.LENGTH_LONG).show();
}
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse
("file://"
+ Environment.getExternalStorageDirectory())));
}
});
}
public class ImagePagerAdapter extends PagerAdapter {
public int[] mImages = new int[] {
R.drawable.p1,
R.drawable.p2,
R.drawable.p3,
.
.
.
R.drawable.p108
};
@Override
public int getCount() {
return mImages.length;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == ((ImageView) object);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
Context context = Photo_gallery.this;
ImageView imageView = new ImageView(context);
int padding = context.getResources().getDimensionPixelSize(
R.dimen.padding_medium);
imageView.setPadding(padding, padding, padding, padding);
imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
imageView.setImageResource(mImages[position]);
((ViewPager) container).addView(imageView, 0);
return imageView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ImageView) object);
}
}
public void onClick(View arg0) {
// TODO Auto-generated method stub
}
}