安卓自定义日历滑动的日历控件

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最近公司项目需要做这个需求，自己才疏学浅，总算能写出个大概来，遂在这里记录下来。

分析

先来分析一下：
首先，我们的需求是可以左右点击查看跳转到下一个月，中间的日历控件可以水平滚动选择日期，所以我们中间的日历控件用一个RecycleView来做，左右两位的为ImageVeiw。
LRCalendarView 总体流程：

1. 编写LRCalendarView的布局R.layout.calendar_view
2. 新建类LRCalendarView继承LinearLayout
3. LRCalendarView添加布局R.layout.calendar_view
4. 数据初始化
5. 构建GalleryAdapter
6. 给RecycleView设置GalleryAdapter并且给左右按钮添加点击事件
7. 处理左右日历翻页逻辑
8. 按需要给RecycleView添加item的点击事件

1. R.layout.calendar_view

"1.0" encoding="utf-8"?>
"http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#ffffff"
    android:padding="5dp"
    android:orientation="horizontal">

    "@+id/iv_left"
        android:layout_gravity="center_vertical"
        android:src="@drawable/ic_launcher"
        android:layout_width="31dp"
        android:layout_height="31dp"/>

    "5dp"
        android:layout_marginRight="5dp"
        android:id="@+id/recyclerView"
        android:layout_width="wrap_content"
        android:layout_weight="1"
        android:layout_height="50dp"
        android:layout_centerVertical="true"
        android:background="#ffffff"
        android:scrollbars="none" />

    "@+id/iv_right"
        android:layout_gravity="center_vertical"
        android:src="@drawable/ic_launcher"
        android:layout_width="30dp"
        android:layout_height="30dp"/>

2. 新建类LRCalendarView继承LinearLayout并添加布局

public class LRCalendarView extends LinearLayout {

    private Context context;
    private ImageView ivLeft, ivRight;
    private RecyclerView mRecyclerView;
    private GalleryAdapter mAdapter;
    private List data = new ArrayList<>();
    private int mCurrYear, mCurrMonth, mCurrDay;
    private int mSelYear, mSelMonth, mSelDay;
    //今天的日期的position
    private int todayPos;

    public LRCalendarView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        this.context = context;
        setupView(context);
    }

    public LRCalendarView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public LRCalendarView(Context context) {
        this(context, null);
    }

    /**
     * 初始化控件
     */
    private void setupView(final Context context) {
        View view = LayoutInflater.from(context).inflate(R.layout.calendar_view, null);
        this.addView(view);

        data = init();
        mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        ivLeft = (ImageView) findViewById(R.id.iv_left);
        ivRight = (ImageView) findViewById(R.id.iv_right);
        //设置manger
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(context);
        linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
        mRecyclerView.setLayoutManager(linearLayoutManager);
        //设置adapter
        mAdapter = new GalleryAdapter(context, init());
        mRecyclerView.setAdapter(mAdapter);

    }
}

public class Cell {

    private String day;
    private String month;
    private int mCurrDay;
    private boolean isSelect;

    public int getmCurrDay() {
        return mCurrDay;
    }

    public void setmCurrDay(int mCurrDay) {
        this.mCurrDay = mCurrDay;
    }

    public String getDay() {
        return day;
    }

    public void setDay(String day) {
        this.day = day;
    }

    public String getMonth() {
        return month;
    }

    public void setMonth(String month) {
        this.month = month;
    }

    public boolean isSelect() {
        return isSelect;
    }

    public void setSelect(boolean select) {
        isSelect = select;
    }

}

接下来都是获取日期数据，可以写在一个工具类里，我直接写在LRCalendarView

    /**
     * 初始化每个月的数据
     */
    private List init() {
        Calendar calendar = Calendar.getInstance();
        mCurrYear = calendar.get(Calendar.YEAR);
        mCurrMonth = calendar.get(Calendar.MONTH);
        mCurrDay = calendar.get(Calendar.DATE);
        return init(mCurrYear, mCurrMonth, mCurrDay, 0);
    }

    /**
     * @param flag  0：正常初始化日期 1：为左右点击的初始化日期
     */
    private List init(int year, int month, int day, int flag) {
        if (flag != 0) {
            day = 1;
        }
        setSelectYearMonth(year, month, day);
        List listData = new ArrayList<>();

        int mMonthDays = getMonthDays(year, month);
        for (int i = 0; i < mMonthDays; i++) {
            Cell cell = new Cell();
            cell.setDay((i + 1) + "");
            cell.setMonth((month + 1) + "月");
            if (i + 1 == day) {
                cell.setmCurrDay(day);
                todayPos = day;
            }
            listData.add(cell);
        }
        return listData;
    }

    private void setSelectYearMonth(int year, int month, int day) {
        mSelYear = year;
        mSelMonth = month;
        mSelDay = day;
    }

    /**
     * 通过年份和月份 得到当月的日子
     *
     * @param year
     * @param month
     * @return
     */
    public int getMonthDays(int year, int month) {
        month++;
        switch (month) {
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                return 31;
            case 4:
            case 6:
            case 9:
            case 11:
                return 30;
            case 2:
                if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) {
                    return 29;
                } else {
                    return 28;
                }
            default:
                return -1;
        }
    }

GalleryAdapter

class GalleryAdapter extends RecyclerView.Adapter {

    private LayoutInflater mInflater;
    private List mDatas;
    /**
     * 用来记录点击的item
     */
    private int selectedPos;
    private boolean isClick;

    public GalleryAdapter(Context context, List data) {
        mInflater = LayoutInflater.from(context);
        this.mDatas = data;
    }

    public void setList(List data) {
        this.mDatas = data;
        isClick = false;
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public ViewHolder(View view) {
            super(view);
            tv1 = (TextView) view.findViewById(R.id.textView1);
            tv2 = (TextView) view.findViewById(R.id.textView2);
            linearLayout = (LinearLayout) view.findViewById(R.id.ll);
        }

        TextView tv1;
        TextView tv2;
        LinearLayout linearLayout;
    }

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

    /**
     * 创建ViewHolder
     */
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View view = mInflater.inflate(R.layout.cell, null);
        ViewHolder viewHolder = new ViewHolder(view);
        return viewHolder;
    }

    /**
     * 设置值
     */
    @Override
    public void onBindViewHolder(final ViewHolder viewHolder, final int i) {

        if (!isClick) {
            selectedPos = Integer.valueOf(mDatas.get(i).getmCurrDay());
            selectedPos -= 1;
        }

        viewHolder.tv1.setText(mDatas.get(i).getDay());
        viewHolder.tv2.setText(mDatas.get(i).getMonth());

        if (selectedPos == i) {
            viewHolder.linearLayout.setSelected(true);
        } else {
            viewHolder.linearLayout.setSelected(false);
        }

        //如果设置了回调，则设置点击事件
        if (mOnItemClickLitener != null) {
            viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    isClick = true;
                    clearSelection(i);
                    notifyDataSetChanged();
                    String date = mDatas.get(i).getMonth() + mDatas.get(i).getDay();
                    mOnItemClickLitener.onItemClick(viewHolder.itemView, i, date);
                }
            });
        }

    }

    public void clearSelection(int pos) {
        selectedPos = pos;
    }

    private OnItemClickLitener mOnItemClickLitener;

    public interface OnItemClickLitener {
        void onItemClick(View view, int position, String date);
    }

    public void setOnItemClickLitener(OnItemClickLitener mOnItemClickLitener) {
        this.mOnItemClickLitener = mOnItemClickLitener;
    }

给左右的ImageView设置点击事件

    ivLeft.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                data.clear();
                data.addAll(onLeftClick(mSelYear, mSelMonth, mSelDay));
                mAdapter.setList(data);
                mAdapter.notifyDataSetChanged();
                mRecyclerView.scrollToPosition(0);
            }
        });

    ivRight.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                data.clear();
                data.addAll(onRightClick(mSelYear, mSelMonth, mSelDay));
                mAdapter.setList(data);
                mAdapter.notifyDataSetChanged();
                mRecyclerView.scrollToPosition(0);
            }
        });

    /**
     * 左点击，日历向后翻页
     */
    public List onLeftClick(int mSelYear, int mSelMonth, int mSelDay) {
        int year = mSelYear;
        int month = mSelMonth;
        int day = mSelDay;

        if (month == 0) {//若果是1月份，则变成12月份
            year = mSelYear - 1;
            month = 11;
        } else if (getMonthDays(year, month) == day) {
            //如果当前日期为该月最后一点，当向前推的时候，就需要改变选中的日期
            month = month - 1;
            day = getMonthDays(year, month);
        } else {
            month = month - 1;
        }

        return init(year, month, day, 1);
    }

    /**
     * 右点击，日历向后翻页
     */
    public List onRightClick(int mSelYear, int mSelMonth, int mSelDay) {
        int year = mSelYear;
        int month = mSelMonth;
        int day = mSelDay;
        if (month == 11) {//若果是12月份，则变成1月份
            year = mSelYear + 1;
            month = 0;
        } else if (getMonthDays(year, month) == day) {
            //如果当前日期为该月最后一点，当向前推的时候，就需要改变选中的日期
            month = month + 1;
            day = getMonthDays(year, month);
        } else {
            month = month + 1;
        }
        return init(year, month, day, 1);
    }

给adapter设置item的点击事件

    mAdapter.setOnItemClickLitener(new GalleryAdapter.OnItemClickLitener() {
            @Override
            public void onItemClick(View view, int position, String date) {
                Toast.makeText(context.getApplicationContext(), date, Toast.LENGTH_SHORT).show();
            }
        });

以上完成后即可在activity中使用

    "@+id/bottom_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

大功告成。