Question

我试图实现如下图所示的事情。这里当recyclerview为空时，它将在页脚中显示摄像机图像视图，当我点击图像时，我可以从摄像机或图库中选择图像（将保存在内部存储文件夹中）并在recyclerview中显示它们。但我在ArrayIndexOutOfBoundsException的onBindViewHolder中获得case 1。如何显示内部文件夹中的图像？

＆＃13;

java.lang.ArrayIndexOutOfBoundsException: length=0; index=-1
                                                                     at java.util.ArrayList.get(ArrayList.java:413)
                                                                     at com.sam.testapp.ImageAdapter.onBindViewHolder(ImageAdapter.java:85)
                                                                     at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6279)
                                                                     at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6312)
                                                                     at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5258)
                                                                     at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5521)
                                                                     at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5363)
                                                                     at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5359)
                                                                     at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2141)
                                                                     at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1525)
                                                                     at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1488)
                                                                     at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:585)
                                                                     at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3506)
                                                                     at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:2969)

＆＃13;

// Activity

public class MainActivity extends AppCompatActivity{

    Toolbar toolbar;
    RecyclerView recycler;
    ImageAdapter adapter;
    private ArrayList<Object> itemList;
    String[] items = new String []  {"http://i.imgur.com/7P2v384.jpg", "http://i.imgur.com/Fb95GwC.jpg", "http://i.imgur.com/qciJxBg.jpg","http://i.imgur.com/h2jgdAd.jpg"};


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        recycler = (RecyclerView)findViewById(R.id.recycler);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(MainActivity.this, OrientationHelper.HORIZONTAL, false);
        recycler.setLayoutManager(linearLayoutManager);
        recycler.setItemAnimator(new DefaultItemAnimator());
        adapter = new ImageAdapter(MainActivity.this, itemList);
        recycler.setAdapter(adapter);

        //Collections.addAll(itemList, items);
        itemList = new ArrayList<Object>(Arrays.asList(items));
        itemList.add(1);

    }




}

＆＃13;

// Adapter

public class ImageAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private Context mContext;
    private static final int TYPE_FOOTER = 0;
    private static final int TYPE_ITEM = 1;
    final CharSequence[] items = {
            "Camera", "Gallery", "Cancel"
    };
    private ArrayList<Object> finalImages = new ArrayList<>();
    private static final String file_path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TESTAPP";


    public ImageAdapter(Context context, ArrayList<Object> itemList) {
        this.finalImages = itemList;
        this.mContext = context;

    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        RecyclerView.ViewHolder viewHolder = null;
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        switch (viewType) {
            case 0:
                View v0 = LayoutInflater.from(parent.getContext()).inflate(R.layout.customrowlayout, parent, false);
                viewHolder = new VHFooter(v0);
                break;
            case 1:
                View v1 = inflater.inflate(R.layout.imagerowlayout, parent, false);
                viewHolder = new VHItem(v1);
                break;
        }
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
        switch (holder.getItemViewType()) {
            case 0:
                VHFooter vh0 = (VHFooter) holder;
                vh0.imgv.setImageResource(R.drawable.camera);
          
                vh0.imgv.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        showDialog();
                    }
                });
                break;
            case 1:
                VHItem vh1 = (VHItem) holder;

                String path = (String) finalImages.get(position);

                if (!TextUtils.isEmpty(path)) {
                    Picasso.with(mContext).load(path).into(vh1.image);
                }
                break;
        }


    }

    private void showDialog() {
        AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
        builder.setItems(items, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int item) {
                if (item == 0) {
                    Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                    ((Activity) mContext).startActivityForResult(intent, 0);
                    dialog.dismiss();
                } else if (item == 1) {
                    Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                    ((Activity) mContext).startActivityForResult(intent, 1);
                    dialog.dismiss();
                } else if (item == 2) {
                    dialog.dismiss();
                }
            }
        });
        AlertDialog alert = builder.create();
        alert.show();
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK && requestCode == 0) {

            savefile(data, true);
            loadfile();


        } else if (resultCode == RESULT_OK && requestCode == 1) {
            savefile(data, false);
            loadfile();
        }
    }

    private void savefile(Intent data, boolean isCamera) {
        if (isCamera) {

            Bitmap bmap = (Bitmap) data.getExtras().get("data");

            File directory = new File(file_path);
            if (!directory.exists()) {
                directory.mkdirs();
            }
            File file = new File(directory, "myimage.jpg");
            try {
                FileOutputStream fos = new FileOutputStream(file);
                bmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
                fos.flush();
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }


        } else {
            Uri uri = data.getData();
            String[] filePathColumn = {MediaStore.Images.Media.DATA};

            Cursor cursor = mContext.getContentResolver().query(uri, filePathColumn, null, null, null);
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String picturePath = cursor.getString(columnIndex);
            cursor.close();

            Bitmap bmap = (BitmapFactory.decodeFile(picturePath));

            File directory = new File(file_path);
            if (!directory.exists()) {
                directory.mkdirs();
            }
            String timeStamp = new SimpleDateFormat("yyyyMMdd-HHmmss", Locale.ENGLISH).format(new Date());
            File file = new File(directory, "IMG_" + timeStamp + ".jpg");
            try {
                FileOutputStream fos = new FileOutputStream(file);
                bmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
                fos.flush();
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }


    }

    private void loadfile() {

        File directory = new File(file_path);
        File newfile[] = directory.listFiles();

        Log.e("sammy_arrlistsize_befor", " " + finalImages.size());

        if (finalImages != null) finalImages.clear();

        for (int i = 0; i < newfile.length; i++) {
            String path = "file://" + newfile[i].getAbsolutePath();
            finalImages.add(path);
            Log.e("sammy_imagepath", " " + path);
        }

        Log.e("sammy_arrlistsize_after", " " + finalImages.size());

        notifyDataSetChanged();

    }


    @Override
    public int getItemCount() {
        return this.finalImages.size();
    }


    @Override
    public int getItemViewType(int position) {

        if (finalImages.get(position) instanceof String) {
            return TYPE_ITEM;
        } else if (finalImages.get(position) instanceof Integer) {
            return TYPE_FOOTER;
        }
        return -1;
    }

    class VHItem extends RecyclerView.ViewHolder {
        ImageView image;

        public VHItem(View itemView) {
            super(itemView);
            image = (ImageView) itemView.findViewById(R.id.image);
        }
    }

    class VHFooter extends RecyclerView.ViewHolder {
        ImageView imgv;

        public VHFooter(View itemView) {
            super(itemView);
            imgv = (ImageView) itemView.findViewById(R.id.imgv);
        }

    }


}

＆＃13;

Answer 1

您的异常被抛出，因为

@Override
public int getItemCount() {
    return this.finalImages.size()+1;
}

应该是

@Override
public int getItemCount() {
    return this.finalImages.size();
}

Answer 2

MainActivity中的第一个

private ArrayList<Object> itemList = new ArrayList<>();
itemList.addAll(yourStringList);
itemList.add(1);

然后使用下面的适配器类

 public class ImageAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

        private Context mContext;
        private static final int TYPE_FOOTER = 0;
        private static final int TYPE_ITEM = 1;
        final CharSequence[] items = {
                "Camera", "Gallery", "Cancel"
        };
        private ArrayList<Object> finalImages = new ArrayList<>();
        private static final String file_path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TESTAPP";


        public ImageAdapter(Context context, ArrayList<Object> itemList) {
            this.finalImages = itemList;
            this.mContext = context;

        }

        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            RecyclerView.ViewHolder viewHolder = null;
            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            switch (viewType) {
                case 0:
                    View v0 = LayoutInflater.from(parent.getContext()).inflate(R.layout.customrowlayout, parent, false);
                    viewHolder = new VHFooter(v0);
                    break;
                case 1:
                    View v1 = inflater.inflate(R.layout.imagerowlayout, parent, false);
                    viewHolder = new VHItem(v1);
                    break;
            }
            return viewHolder;
        }

        @Override
        public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
            switch (holder.getItemViewType()) {
                case 0:
                    VHFooter vh0 = (VHFooter) holder;
                    vh0.imgv.setImageResource(R.drawable.camera);
    //                Picasso.with(mContext).load(R.drawable.camera).into(vh0.imgv);
//piccaso is commented for now 
                    vh0.imgv.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            showDialog();
                        }
                    });
                    break;
                case 1:
                    VHItem vh1 = (VHItem) holder;

                    String path = (String) finalImages.get(position);

                    if (!TextUtils.isEmpty(path)) {
                        Picasso.with(mContext).load(path).into(vh1.image);
                    }
                    break;
            }


        }

        private void showDialog() {
            AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
            builder.setItems(items, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int item) {
                    if (item == 0) {
                        Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                        ((Activity) mContext).startActivityForResult(intent, 0);
                        dialog.dismiss();
                    } else if (item == 1) {
                        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                        ((Activity) mContext).startActivityForResult(intent, 1);
                        dialog.dismiss();
                    } else if (item == 2) {
                        dialog.dismiss();
                    }
                }
            });
            AlertDialog alert = builder.create();
            alert.show();
        }

        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            if (resultCode == RESULT_OK && requestCode == 0) {

                savefile(data, true);
                loadfile();


            } else if (resultCode == RESULT_OK && requestCode == 1) {
                savefile(data, false);
                loadfile();
            }
        }

        private void savefile(Intent data, boolean isCamera) {
            if (isCamera) {

                Bitmap bmap = (Bitmap) data.getExtras().get("data");

                File directory = new File(file_path);
                if (!directory.exists()) {
                    directory.mkdirs();
                }
                File file = new File(directory, "myimage.jpg");
                try {
                    FileOutputStream fos = new FileOutputStream(file);
                    bmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
                    fos.flush();
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }


            } else {
                Uri uri = data.getData();
                String[] filePathColumn = {MediaStore.Images.Media.DATA};

                Cursor cursor = mContext.getContentResolver().query(uri, filePathColumn, null, null, null);
                cursor.moveToFirst();

                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                String picturePath = cursor.getString(columnIndex);
                cursor.close();

                Bitmap bmap = (BitmapFactory.decodeFile(picturePath));

                File directory = new File(file_path);
                if (!directory.exists()) {
                    directory.mkdirs();
                }
                String timeStamp = new SimpleDateFormat("yyyyMMdd-HHmmss", Locale.ENGLISH).format(new Date());
                File file = new File(directory, "IMG_" + timeStamp + ".jpg");
                try {
                    FileOutputStream fos = new FileOutputStream(file);
                    bmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
                    fos.flush();
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }


        }

        private void loadfile() {

            File directory = new File(file_path);
            File newfile[] = directory.listFiles();

            Log.e("sammy_arrlistsize_befor", " " + finalImages.size());

            if (finalImages != null) finalImages.clear();

            for (int i = 0; i < newfile.length; i++) {
                String path = "file://" + newfile[i].getAbsolutePath();
                finalImages.add(path);
                Log.e("sammy_imagepath", " " + path);
            }

            Log.e("sammy_arrlistsize_after", " " + finalImages.size());

            notifyDataSetChanged();

        }


        @Override
        public int getItemCount() {
            return this.finalImages.size();
        }


        @Override
        public int getItemViewType(int position) {

            if (finalImages.get(position) instanceof String) {
                return TYPE_ITEM;
            } else if (finalImages.get(position) instanceof Integer) {
                return TYPE_FOOTER;
            }
            return -1;
        }

        class VHItem extends RecyclerView.ViewHolder {
            ImageView image;

            public VHItem(View itemView) {
                super(itemView);
                image = (ImageView) itemView.findViewById(R.id.image);
            }
        }

        class VHFooter extends RecyclerView.ViewHolder {
            ImageView imgv;

            public VHFooter(View itemView) {
                super(itemView);
                imgv = (ImageView) itemView.findViewById(R.id.imgv);
            }

        }


    }

recyclerview页脚单击以加载图像

2 个答案: