使用viewPager的图像滑块.滑动时冻结 [英] Image slider using viewPager. freeze while sliding

问题描述

我创建了一个应用，该应用从图库中获取图像，并在VewPager中显示，我们可以对其进行滑动.唯一的问题是，如果图像大小大于1mb，则幻灯片会冻结，滞后.如果我在图库中添加图像100-200kb，则不会冻结.有什么办法吗?谢谢.

I'm created app, which gets images from gallery, shows in VewPager and we can slide it. There only problem is that if the image size is more than 1mb, the slide freezes, lagging. If i add images in gallery 100-200kb, that not freeze. Any solution? Thanks.

在这里适配器.

public class PhotoPagerAdapter extends PagerAdapter {

private ImageView imageView;
private Context context;
private LayoutInflater inflater;
private ArrayList<String> listOfAllImages = new ArrayList<>();
private ArrayList<Bitmap> listOfAllBitmap = new ArrayList<>();

public PhotoPagerAdapter(Context context) {
    this.context = context;
    getAllShownImagesPath();
}

@Override
public int getCount() {
    return listOfAllImages.size();
}

@Override
public boolean isViewFromObject(View view, Object object) {
    return view == object;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View view = inflater.inflate(R.layout.photopager, null);
    imageView = (ImageView) view.findViewById(R.id.photoView2);


    imageView.setImageBitmap(listOfAllBitmap.get(position));
    imageView.setRotation(90);

    ViewPager viewPager = (ViewPager) container;
    viewPager.addView(view, 0);
    return view;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    ViewPager vp = (ViewPager) container;
    View view = (View) object;
    vp.removeView(view);
}

private void getAllShownImagesPath() {
    Uri uri;
    Cursor cursor;
    int column_index_data;
    String absolutePathOfImage;
    uri = android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

    String[] projection = {MediaStore.MediaColumns.DATA,
            MediaStore.Images.Media.BUCKET_DISPLAY_NAME};

    cursor = context.getContentResolver().query(uri, projection, null,
            null, null);

    column_index_data = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
    while (cursor.moveToNext()) {
        absolutePathOfImage = cursor.getString(column_index_data);
        listOfAllImages.add(absolutePathOfImage);
        listOfAllBitmap.add(BitmapFactory.decodeFile(absolutePathOfImage));
    }

    cursor.close();
}
}

这是片段.

public class ShowCamera2 extends BaseFragment{

private View mainView;
private ViewPager viewPager;
private PhotoPagerAdapter photoPagerAdapter;
private Button prev, next;
private TextView imageCount;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    mainView = inflater.inflate(R.layout.camera_fragment, container, false);

    prev = (Button) mainView.findViewById(R.id.prevPhoto2);
    next = (Button) mainView.findViewById(R.id.nextPhoto2);

    viewPager = (ViewPager) mainView.findViewById(R.id.viewPager);
    photoPagerAdapter = new PhotoPagerAdapter(this.getActivity());
    viewPager.setAdapter(photoPagerAdapter);

    prev.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            viewPager.setCurrentItem(viewPager.getCurrentItem() - 1);
        }
    });

    next.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            viewPager.setCurrentItem(viewPager.getCurrentItem() + 1);
        }
    });

    return mainView;
}
}

有人可以帮助我吗?谢谢您的阅读.

Anyone can help me? Thank you for reading.

这里是更新.

public class PhotoPagerAdapter extends PagerAdapter {

private ImageView imageView;
private Context context;
private LayoutInflater inflater;
private ArrayList<String> listOfAllImages = new ArrayList<>();
private ArrayList<Bitmap> listOfAllBitmap = new ArrayList<>();

public PhotoPagerAdapter(Context context) {
    this.context = context;
    getAllShownImagesPath();
}

@Override
public int getCount() {
    return listOfAllBitmap.size();
}

@Override
public boolean isViewFromObject(View view, Object object) {
    return view == object;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View view = inflater.inflate(R.layout.photopager, null);
    imageView = (ImageView) view.findViewById(R.id.photoView2);


    imageView.setImageBitmap(listOfAllBitmap.get(position));
    imageView.setRotation(90);

    ViewPager viewPager = (ViewPager) container;
    viewPager.addView(view, 0);
    return view;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    ViewPager vp = (ViewPager) container;
    View view = (View) object;
    vp.removeView(view);
}

private void getAllShownImagesPath() {
    Uri uri;
    Cursor cursor;
    int column_index_data;
    String absolutePathOfImage;
    uri = android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

    String[] projection = {MediaStore.MediaColumns.DATA,
            MediaStore.Images.Media.BUCKET_DISPLAY_NAME};

    cursor = context.getContentResolver().query(uri, projection, null,
            null, null);

    column_index_data = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
    while (cursor.moveToNext()) {
        absolutePathOfImage = cursor.getString(column_index_data);
        //listOfAllImages.add(absolutePathOfImage);
        listOfAllBitmap.add(decodeBitmapURI(context, absolutePathOfImage, 1000, 500));
    }

    cursor.close();
}

public Bitmap decodeBitmapURI(Context context, String uri, int imageWidth, int imageHeight) {

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    try {
        BitmapFactory.decodeStream(context.getContentResolver().openInputStream(Uri.parse(uri)), null, options);
        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, imageWidth, imageHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeStream(context.getContentResolver().openInputStream(Uri.parse(uri)), null, options);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

    return null;
}

public int calculateInSampleSize(
        BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {

        final int halfHeight = height / 2;
        final int halfWidth = width / 2;

        // Calculate the largest inSampleSize value that is a power of 2 and keeps both
        // height and width larger than the requested height and width.
        while ((halfHeight / inSampleSize) >= reqHeight
                && (halfWidth / inSampleSize) >= reqWidth) {
            inSampleSize *= 2;
        }
    }

    return inSampleSize;
}
}

推荐答案

我使用了Glide，这对我有所帮助.

I used Glide, and this helped me.

public class ImageAdapter extends PagerAdapter {

private ImageView imageView;
private Context context;
private LayoutInflater inflater;
private ArrayList<String> listOfAllImages = new ArrayList<>();

public ImageAdapter(Context context) {
    this.context = context;
    getAllShownImagesPath();
}


@Override
public int getCount() {
    return listOfAllImages.size();
}

@Override
public boolean isViewFromObject(View view, Object object) {
    return view == object;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View view = inflater.inflate(R.layout.photopager, null);
    imageView = (ImageView) view.findViewById(R.id.photoView2);

    Glide.with(context).load(listOfAllImages.get(position))
            .thumbnail(1f)
            .crossFade()
            .diskCacheStrategy(DiskCacheStrategy.ALL)
            .into(imageView);

    ViewPager viewPager = (ViewPager) container;
    viewPager.addView(view, 0);
    return view;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    ViewPager vp = (ViewPager) container;
    View view = (View) object;
    vp.removeView(view);
}

private void getAllShownImagesPath() {
    Uri uri;
    Cursor cursor;
    int column_index_data;
    String absolutePathOfImage;
    uri = android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

    String[] projection = {MediaStore.MediaColumns.DATA,
            MediaStore.Images.Media.BUCKET_DISPLAY_NAME};

    cursor = context.getContentResolver().query(uri, projection, null,
            null, null);

    column_index_data = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
    while (cursor.moveToNext()) {
        absolutePathOfImage = cursor.getString(column_index_data);
        listOfAllImages.add(absolutePathOfImage);
    }

    cursor.close();
}
}

这篇关于使用viewPager的图像滑块.滑动时冻结的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！