android.support.v7.widget.LinearLayoutManager#scrollToPosition ( )源码实例Demo

@SuppressLint("CheckResult")
public DialogHolder(View itemView) {
    super(itemView);

    initUi(itemView);

    LinearLayoutManager layoutManager = new LinearLayoutManager(itemView.getContext());
    layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
    layoutManager.scrollToPosition(0);

    filterRecycler.setLayoutManager(layoutManager);
    filterRecycler.setHasFixedSize(true);
    filterRecycler.setItemAnimator(new DefaultItemAnimator());

    RxTextView.textChanges(searchEdt)
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(charSequence -> {
                getAdapter().filter(charSequence.toString());
            });
}
 

private void moveToPosition(int position) {
    if (position > data.size())
        return;
    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    int first = layoutManager.findFirstVisibleItemPosition();
    int end = layoutManager.findLastVisibleItemPosition();
    if (first == -1 || end == -1)
        return;
    if (position <= first) {
        layoutManager.scrollToPosition(position);
    } else if (position >= end) {
        isMove = true;
        scrollPosition = position;
        layoutManager.smoothScrollToPosition(recyclerView, null, position);
    } else {//中间部分
        int n = position - layoutManager.findFirstVisibleItemPosition();
        if (n > 0 && n < data.size()) {
            int top = layoutManager.findViewByPosition(position).getTop();
            recyclerView.scrollBy(0, top);
        }
    }
}
 

public void collapseChildrenComment(int position) {
    ArrayList<Comment> childrenComments = new ArrayList<>();
    Comment parentComment = (Comment) mItemList.get(position);
    LinearLayoutManager linearLayoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
    // if a comment header is not visible when collapsing, scroll to it's header
    if (position != linearLayoutManager.findFirstCompletelyVisibleItemPosition()) {
        linearLayoutManager.scrollToPosition(position);
    }

    for (int curPosition = position + 1;
         (mItemList.get(curPosition) instanceof Comment
             && ((Comment) mItemList.get(curPosition)).getLevel() > parentComment.getLevel());
         curPosition++) {
        childrenComments.add((Comment) mItemList.get(curPosition));
    }

    if (!childrenComments.isEmpty()) {
        mCollapsedChildrenCommentsIndex.put(parentComment.getCommentId(), childrenComments);
        for (Comment comment : childrenComments) {
            mItemList.remove(comment);
        }
        notifyItemChanged(position);
        notifyItemRangeRemoved(position + 1, childrenComments.size());
    }
}
 

private void initHorizontalList() {
    LinearLayoutManager layoutManager = new LinearLayoutManager(this);
    layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
    layoutManager.scrollToPosition(0);
    thumbListView.setLayoutManager(layoutManager);
    thumbListView.setHasFixedSize(true);
    bindDataToAdapter();
}
 

private void initHorizontalList() {
    LinearLayoutManager layoutManager = new LinearLayoutManager(this);
    layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
    layoutManager.scrollToPosition(0);
    thumbListView.setLayoutManager(layoutManager);
    thumbListView.setHasFixedSize(true);
    bindDataToAdapter();
}
 

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_blog_transition);

    initViews();

    // Setup layout manager for mBlogList and column count
    final LinearLayoutManager layoutManager = new LinearLayoutManager(this);

    // Control orientation of the mBlogList
    layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
    layoutManager.scrollToPosition(0);
    // Attach layout manager
    mRecyclerView.setLayoutManager(layoutManager);

    // Bind adapter to recycler
    mBlogList = new ArrayList<>();


    // Some of colors
    int[] color = {0xFFC2185B, 0xFFB3E5FC, 0xFFFFEB3B, 0xFFF8BBD0, 0xFFFF5252,
            0xFFE91E63, 0xFF448AFF, 0xFF00796B, 0xFFE91E63, 0xFFFF5252, 0xFFF8BBD0, 0xFF0288D1,};
    // Some of images
    int[] drawable = {R.drawable.apple_46, R.drawable.apple_style, R.drawable.steve_jobs,
            R.drawable.apple_46, R.drawable.apple_style, R.drawable.steve_jobs, R.drawable.apple_46,
            R.drawable.apple_style, R.drawable.steve_jobs, R.drawable.apple_46, R.drawable.apple_style,
            R.drawable.steve_jobs};

    //
    for (int i = 0; i < color.length; i++) {
        Blog blog = new Blog();
        blog.setImageRes(drawable[i]);
        blog.setBackGroundColor(color[i]);
        blog.setTitle("Label " + i);
        blog.setSubTitle("This is subTitle with number " + i + " and some description here");
        mBlogList.add(blog);
    }

    // Setting adapter
    final BlogRecyclerAdapter adapter = new BlogRecyclerAdapter(mBlogList);
    mRecyclerView.setAdapter(adapter);

    // Listen to the item touching
    mRecyclerView
            .addOnItemTouchListener(new RecyclerItemClickListener(
                    this,
                    new RecyclerItemClickListener.OnItemClickListener() {
                        @Override
                        public void onItemClick(View itemView, int position) {
                            if (!isOpen) {
                                BlogTransitionActivity.this.position = position;
                                openBlogInDetails(itemView);
                            }

                        }
                    }));
}
 

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.recycler_view_sample);
        mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);

        // use this setting to improve performance if you know that changes
        // in content do not change the layout size of the RecyclerView
        mRecyclerView.setHasFixedSize(true);

        // use a linear layout manager
        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        // specify an adapter (see also next example)
        String[] mDataset = new String[4];
        for (int i = 0; i < 4; i++) {
            mDataset[i] = i + "hh";
        }
        mAdapter = new MyAdapter(mDataset);
        mRecyclerView.setAdapter(mAdapter);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);

        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);

        layoutManager.scrollToPosition(0);

        mRecyclerView.setLayoutManager(layoutManager);
//        RecyclerView.ItemDecoration itemDecoration =
//        new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST);
//        mRecyclerView.addItemDecoration(itemDecoration);

// this is the default;
// this call is actually only necessary with custom ItemAnimators
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());

// onClickDetection is done in this Activity's OnItemTouchListener
// with the help of a GestureDetector;
// Tip by Ian Lake on G+ in a comment to this post:
// https://plus.google.com/+LucasRocha/posts/37U8GWtYxDE
//        mRecyclerView.addOnItemTouchListener(this);
//        gesturedetector =
//        new GestureDetectorCompat(this, new RecyclerViewDemoOnGestureListener());



    }
 

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.recycler_view_sample);
        mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);

        // use this setting to improve performance if you know that changes
        // in content do not change the layout size of the RecyclerView
        mRecyclerView.setHasFixedSize(true);

        // use a linear layout manager
        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        // specify an adapter (see also next example)
        String[] mDataset = new String[4];
        for (int i = 0; i < 4; i++) {
            mDataset[i] = i + "hh";
        }
        mAdapter = new MyAdapter(mDataset);
        mRecyclerView.setAdapter(mAdapter);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);

        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);

        layoutManager.scrollToPosition(0);

        mRecyclerView.setLayoutManager(layoutManager);
//        RecyclerView.ItemDecoration itemDecoration =
//        new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST);
//        mRecyclerView.addItemDecoration(itemDecoration);

// this is the default;
// this call is actually only necessary with custom ItemAnimators
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());

// onClickDetection is done in this Activity's OnItemTouchListener
// with the help of a GestureDetector;
// Tip by Ian Lake on G+ in a comment to this post:
// https://plus.google.com/+LucasRocha/posts/37U8GWtYxDE
//        mRecyclerView.addOnItemTouchListener(this);
//        gesturedetector =
//        new GestureDetectorCompat(this, new RecyclerViewDemoOnGestureListener());



    }