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 build.gradle Îļþ:

repositories {
    // ...
    maven { url "https://jitpack.io" }
}
dependencies {
    // ...
    compile('com.afollestad:drag-select-recyclerview:0.1.0@aar') {
        transitive = true
    }
}

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DragSelectRecyclerView

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<com.afollestad.dragselectrecyclerview.DragSelectRecyclerView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical" />

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DragSelectRecyclerView list = (DragSelectRecyclerView) findViewById(R.id.list);
list.setLayoutManager(new GridLayoutManager(this, 3));
list.setAdapter(adapter);

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DragSelectRecyclerViewAdapter

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public class MainAdapter extends DragSelectRecyclerViewAdapter<MainAdapter.MainViewHolder>
        implements View.OnClickListener, View.OnLongClickListener {
    // Receives View.OnClickListener set in onBindViewHolder(), tag contains index
    @Override
    public void onClick(View v) {
        if (v.getTag() != null) {
            int index = (int) v.getTag();
            // Forwards to the adapter's constructor callback
            if (mCallback != null) mCallback.onClick(index);
        }
    }
    // Receives View.OnLongClickListener set in onBindViewHolder(), tag contains index
    @Override
    public boolean onLongClick(View v) {
        if (v.getTag() != null) {
            int index = (int) v.getTag();
            // Forwards to the adapter's constructor callback
            if (mCallback != null) mCallback.onLongClick(index);
            return true;
        }
        return false;
    }
    public interface ClickListener {
        void onClick(int index);
        void onLongClick(int index);
    }
    private final ClickListener mCallback;
    // Constructor takes click listener callback
    protected MainAdapter(ClickListener callback) {
        super();
        mCallback = callback;
    }
    @Override
    public MainViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.griditem_main, parent, false);
        return new MainViewHolder(v);
    }
    @Override
    public void onBindViewHolder(MainViewHolder holder, int position) {
        // Sets position + 1 to a label view
        holder.label.setText(String.format("%d", position + 1));
        if (isIndexSelected(position)) {
            // Item is selected, change it somehow 
        } else {
            // Item is not selected, reset it to a non-selected state
        }
        // Tag is used to retrieve index from the click/long-click listeners
        holder.itemView.setTag(position);
        holder.itemView.setOnClickListener(this);
        holder.itemView.setOnLongClickListener(this);
    }
    @Override
    public int getItemCount() {
        return 60;
    }
    public class MainViewHolder extends RecyclerView.ViewHolder {
        public final TextView label;
        public MainViewHolder(View itemView) {
            super(itemView);
            this.label = (TextView) itemView.findViewById(R.id.label);
        }
    }
}

You choose what to do when an item is selected (in onBindViewHolder). isIndexSelected(int)returns true or false. The click listener implementation used here will aid in the next section.

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---

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public class MainActivity extends AppCompatActivity implements
        MainAdapter.ClickListener, DragSelectRecyclerViewAdapter.SelectionListener {
    private DragSelectRecyclerView mList;
    private MainAdapter mAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Setup adapter and callbacks
        mAdapter = new MainAdapter(this);
        // Listen for selection changes to update indicators
        mAdapter.setSelectionListener(this);
        // Restore selected indices after Activity recreation
        mAdapter.restoreInstanceState(savedInstanceState);
        // Setup the RecyclerView
        mList = (DragSelectRecyclerView) findViewById(R.id.list);
        mList.setLayoutManager(new GridLayoutManager(this, getResources().getInteger(R.integer.grid_width)));
        mList.setAdapter(mAdapter);
    }
    @Override
    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
        super.onSaveInstanceState(outState, outPersistentState);
        // Save selected indices to be restored after recreation
        mAdapter.saveInstanceState(outState);
    }
    @Override
    public void onClick(int index) {
        // Single click will select or deselect an item
        mAdapter.toggleSelected(index);
    }
    @Override
    public void onLongClick(int index) {
        // Long click initializes drag selection, and selects the initial item
        mList.setDragSelectActive(true, index);
    }
    @Override
    public void onDragSelectionChanged(int count) {
        // TODO Selection was changed, updating an indicator, e.g. a Toolbar or contextual action bar
    }
}

DragSelectRecyclerViewAdapter°üº¬ÁËÐí¶à¿ÉÒÔ°ïÖúÄãµÄ·½·¨£¡

// Clears all selected indices
adapter.clearSelected();
// Sets an index as selected (true) or unselected (false);
adapter.setSelected(index, true);
// If an index is selected, unselect it. Otherwise select it. Returns new selection state.
boolean selectedNow = adapter.toggleSelected(index);
// Gets the number of selected indices
int count = adapter.getSelectedCount();
// Gets all selected indices
Integer\[\] selectedItems = adapter.getSelectedIndices();
// Checks if an index is selected, useful in adapter subclass
boolean selected = adapter.isIndexSelected(index);
// Sets a listener that's notified of selection changes, used in the section above
adapter.setSelectionListener(listener);
// Used in section above, saves selected indices to Bundle
adapter.saveInstanceState(outState);
// Used in section above, restores selected indices from Bundle
adapter.restoreInstanceState(inState);