Android View Pager 从文件夹中删除图像不刷新

Question

每当我从 ViewPager 中删除图像时。然后有时下一张图片会被删除。或者有时没有图像删除。

我不知道哪里错了。

我的画廊 Activity

public class GalleryActivity extends AppCompatActivity implements View.OnClickListener {

    ImageButton imgBtnDelete;
    TextView tvImageCount;
    ViewPager galleryViewPager;
    GalleryAdapter adapter;
    private static String filePath = "";
    public int mPosition = 0;

    // File Code
    public File mDirectory;
    File[] imageList;
    ArrayList<Integer> mTotalImages = new ArrayList<>();
    ArrayList<String> mFilePaths = new ArrayList<>();
    Uri[] mUrls;
    String[] mFiles, mFileNames;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Hide the Status bar...Write Before setContentView()
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        setContentView(R.layout.activity_gallery);

        imgBtnDelete = (ImageButton) findViewById(R.id.imgBtnDelete);

        imgBtnDelete.setOnClickListener(this);

        // File Code
        mDirectory = new File(android.os.Environment.getExternalStorageDirectory(), "CameraApp/Images");

        imageList = mDirectory.listFiles(new FilenameFilter() {
            @Override
            public boolean accept(File file, String name) {
                return ((name.endsWith(".jpg")) || (name.endsWith(".png")) || (name.endsWith(".mp4")));
            }
        });

        int imgLength = (imageList == null) ? 0 : imageList.length;
        if (imgLength > 0) {
            mFiles = new String[imgLength];

            // add imgLength here for set Total Images in TextView
            for (int k = 0; k < imageList.length; k++) {
                mTotalImages.add(imgLength);
                filePath = imageList[k].getAbsolutePath();
                mFilePaths.add(filePath);
            }

            mFileNames = new String[imgLength];

            tvImageCount.setVisibility(View.VISIBLE);
            tvImageCount.setText(1 + "/" + mTotalImages.size());

            mUrls = new Uri[imgLength];

            int i, j = 0;
            for (i = imgLength - 1; i >= 0; i--) {
                mFiles[j] = imageList[i].getAbsolutePath();
                mFileNames[j] = imageList[i].getName();
                j++;
            }

            galleryViewPager = (ViewPager) findViewById(R.id.galleryViewPager);
            adapter = new GalleryAdapter(this, mFiles);
            galleryViewPager.setAdapter(adapter);
            galleryViewPager.setOnPageChangeListener(pageChangeListener);
        } else {
            tvImageCount.setVisibility(View.INVISIBLE);
            Toast.makeText(this, "Please capture some images from App!", Toast.LENGTH_SHORT).show();
        }
    }

    OnPageChangeListener pageChangeListener = new OnPageChangeListener() {

        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }

        @Override
        public void onPageSelected(int position) {
            mPosition = position;
            tvImageCount.setText((position + 1) + "/" + mTotalImages.size());
            Toast.makeText(GalleryActivity.this, "mPosition is :  " + mPosition, Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onPageScrollStateChanged(int state) {
        }
    };

    private void openAlert() {
        new AlertDialog.Builder(this)
                .setTitle("Delete Image")
                .setMessage("Are you sure you want to delete this Image?")
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // continue with delete
                        DeleteImage();
                        adapter.notifyDataSetChanged();
                    }
                })
                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // do nothing
                        dialog.dismiss();
                    }
                })
                .setIcon(android.R.drawable.ic_dialog_alert)
                .setCancelable(true)
                .show();
    }

我的DeleteImage()

private void DeleteImage() {
    File file = new File(mFilePaths.get(mPosition));
    boolean deleted = file.delete();

    if (deleted) {
        mFilePaths.remove(mPosition);
        if (mFilePaths.size() == 0) {
            tvImageCount.setVisibility(View.INVISIBLE);
        }
        if (mFilePaths.size() != 0 && mFilePaths.size() != 1) {
            adapter.notifyDataSetChanged();
            galleryViewPager.setCurrentItem(mPosition + 1);
        }
    }
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
        Uri contentUri = Uri.fromFile(file);
        mediaScanIntent.setData(contentUri);
        this.sendBroadcast(mediaScanIntent);
    } else {
        sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"
                + Environment.getExternalStorageDirectory())));
    }
}

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.imgBtnDelete:
                if (mDirectory.exists() && mDirectory != null && mFilePaths.size() != 0) {
                    openAlert();
                } else {
                    Toast.makeText(this, "No Images to Delete!", Toast.LENGTH_SHORT).show();
                }
                break;

            default:
                break;
        }
    }

下面是我的Viewpager的GallaryAdapter

public class GalleryAdapter extends PagerAdapter {

    private Context mContext;

    private String[] mFiles;

    public GalleryAdapter(Context mContext, String[] mFiles) {
        this.mContext = mContext;
        this.mFiles = mFiles;
    }

    @Override
    public int getCount() {
        return mFiles.length;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        LayoutInflater mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View itemView = mLayoutInflater.inflate(R.layout.gallary_viewpager_item, container, false);

        ImageView mImageView = (ImageView) itemView.findViewById(R.id.imgViewCenterGallery);

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;

        Bitmap bitmap;
        bitmap = BitmapFactory.decodeFile(mFiles[position], options);

        mImageView.setImageBitmap(bitmap);

        container.addView(itemView);

        return itemView;
    }

    public int getItemPosition(Object object) {
        return PagerAdapter.POSITION_NONE;
    }

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

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

Answer 1

试试这个

if (imgLength > 0) {
        mFiles = new String[imgLength];

        mFileNames = new String[imgLength];

        mUrls = new Uri[imgLength];

        int j=0;
        for (int i = imgLength-1; i >= 0; i--) {
            mFiles[j] = imageList[i].getAbsolutePath();
            mFileNames[j] = imageList[i].getName();
            j++;
            Toast.makeText(this, "Image Name - " + Arrays.toString(mFileNames), Toast.LENGTH_SHORT).show();

            galleryViewPager = (ViewPager) findViewById(R.id.galleryViewPager);
            adapter = new GallerySlideImageAdapter(this, mFiles, mFileNames);
            galleryViewPager.setAdapter(adapter);
        }
    } else {
        Toast.makeText(this, "Please capture some images from App !", Toast.LENGTH_SHORT).show();
    }