我正在使用Glide在Viewpager中显示来自服务器的图像。我有一个按钮,用户可以在单击时保存当前图像。
// Code from FullImage Fragment
save_img.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(myViewPagerAdapter.getBitmap() != null)
saveImage(myViewPagerAdapter.getBitmap());
}
});
我从ViewpagerAdapter获得位图,就像这样 -
public class MyViewPagerAdapter extends PagerAdapter {
Context context;
Bitmap bitmap;
private ArrayList<Object> imagesList = new ArrayList<>();
public MyViewPagerAdapter(Context context, ArrayList<Object> images) {
context = this.context;
this.imagesList = images;
}
@NonNull
@SuppressLint("ClickableViewAccessibility")
@Override
public Object instantiateItem(@NonNull final ViewGroup container, int position) {
Object recyclerViewItem = imagesList.get(position);
final View view = LayoutInflater.from(container.getContext()).inflate(R.layout.util_image_fullscreen_preview, container, false);
final TouchImageView imageViewPreview = view.findViewById(R.id.image_preview);
ProgressBar progressBar = new ProgressBar(view.getContext(), null, android.R.attr.progressBarStyleSmall);
progressBar.setVisibility(View.VISIBLE);
if (recyclerViewItem instanceof Advertiser) {
Advertiser advertiser = (Advertiser) imagesList.get(position);
GlideApp
.with(container.getContext())
.asBitmap()
.load(advertiser.getUrl())
.fitCenter().diskCacheStrategy(DiskCacheStrategy.ALL)
.into(new SimpleTarget<Bitmap>() {
@Override
public void onResourceReady(@NonNull Bitmap resource, Transition<? super Bitmap> transition) {
imageViewPreview.setImageBitmap(resource);
}
});
;
} else {
Photos image = (Photos) imagesList.get(position);
GlideApp
.with(container.getContext())
.asBitmap()
.load(image.getUrl())
.diskCacheStrategy(DiskCacheStrategy.ALL)
.into(new SimpleTarget<Bitmap>() {
@Override
public void onResourceReady(@NonNull Bitmap resource, Transition<? super Bitmap> transition) {
bitmap = resource;
imageViewPreview.setImageBitmap(resource);
}
});
}
container.addView(view);
return view;
}
@Override
public int getCount() {
return imagesList.size();
}
@Override
public boolean isViewFromObject(View view, Object obj) {
return view.equals(obj);
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
public interface OnClickListener {
void performClick();
}
public Bitmap getBitmap() {
return bitmap;
}
}
我的问题是这段代码有效,但它正在保存来自 viewpager 的下一张图像(我知道 viewpager 加载了 3 张图像,下一个、当前和上一个(。 现在如何获取当前位图?
- 添加一个变量 mMap,该类型是为您的视图页面
SparseArray<Bitmap>
在位图完全加载后放置位图 - 为您的 ViewPager 添加一个变量 mCurrentPosition,并在方法实例化项中设置其值
- 更改getBitmap的逻辑,例如以下代码片段
通过以下代码替换您的 getBitmap
public Bitmap getBitmap(int pos){
return mMap.get(pos);
}
redit:关于如何清除变量 mMap 并初始化它。
public class MyViewPagerAdapter extends PagerAdapter {
...
Context context;
SparseArray<Bitmap> mMap = new SparseArray<Bitmap>();
...
}
public Object instantiateItem(@NonNull final ViewGroup container, int position) {
...
//add your bitmap in here after it load complete
mMap.put(position,bitmap)
...
}
重新编辑:在保存图像中应如下所示:
saveImage(myViewPagerAdapter.getBitmap(position));