一步一步構建本身的簡單日曆控件 MySimpleCalendar

日曆控件你們應該不陌生，github 上面一搜一大堆，可是咱們拿到 github 上面的一個日曆控件，想動手改改功能改改需求，有時可能會以爲無從下手，（固然了，老司機就忽略我說的 —。—）那麼，若是想知道一個日曆控件是如何從無到有構建起來的，不妨各位看官快速瀏覽一下個人這篇文章。 文章主要是帶你們一步一步熟悉構建的流程，並無什麼特別酷炫狂拽的效果。

先上一個效果圖鎮鎮樓。

1、數據準備

一、實體類 MyCalendarBean

/**
 * Created by deeson.woo
 */
public class MyCalendarBean {

    private int year;
    private int month;//1-12
    private int day;//1-31

    public MyCalendarBean(int year, int month, int day) {
        this.year = year;
        this.month = month;
        this.day = day;
    }

    public int getYear() {
        return year;
    }

    public int getMonth() {
        return month;
    }

    public int getDay() {
        return day;
    }
}
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二、構建日期實體

/**
     * 構建具體一天的對象
     * @param year
     * @param month
     * @param day
     * @return
     */
    public MyCalendarBean generateCalendarBean(int year, int month, int day) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month - 1, day);
        year = calendar.get(Calendar.YEAR);
        month = calendar.get(Calendar.MONTH) + 1;
        day = calendar.get(Calendar.DATE);

        return new MyCalendarBean(year, month, day);
    }
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三、打印當前月份的全部日期

/**
     * 獲取當前月份的日期列表
     * @param year
     * @param month
     * @return
     */
    public List<MyCalendarBean> getDaysListOfMonth(int year, int month) {

        List<MyCalendarBean> list = new ArrayList<>();

        int daysOfMonth = getDaysOfCertainMonth(year, month);

        for (int i = 0; i < daysOfMonth; i++) {
            MyCalendarBean bean = generateCalendarBean(year, month, i + 1);
            list.add(bean);
        }
        return list;
    }

    /**
     * 獲取具體月份的最大天數
     *
     * @param year
     * @param month
     * @return
     */
    public static int getDaysOfCertainMonth(int year, int month) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month - 1, 1);
        return calendar.getActualMaximum(Calendar.DATE);
    }
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//測試打印2018年2月份
printDaysList(getDaysListOfMonth(2018, 2));
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2018年2月 = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28 }

2、展現日期

一、將月份的全部日期按照7列展現

自定義ViewGroup（MonthCalendarView）

/**
 * Created by deeson.woo
 * 月份視圖
 */

public class MonthCalendarView extends ViewGroup {

    private int column = 7;

    public MonthCalendarView(Context context) {
        super(context);
    }

    public MonthCalendarView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

}
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（1）onMeasure（）方法

• 拿到控件的寬度，分紅七份，賦給 item 的寬度和高度
• 同時計算控件所需的高度

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        
        int parentWidth = MeasureSpec.getSize(MeasureSpec.makeMeasureSpec(widthMeasureSpec, MeasureSpec.EXACTLY));

        //將寬度平均分紅七份，每一個item的寬高都等於它
        int itemWidth = parentWidth / column;
        int itemHeight = itemWidth;

        int parentHeight = 0;

        for (int i = 0; i < getChildCount(); i++) {
            View childView = getChildAt(i);
            childView.measure(MeasureSpec.makeMeasureSpec(itemWidth, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(itemHeight, MeasureSpec.EXACTLY));
            
            //計算控件所需的高度
            if (i % column == 0) {
                parentHeight += childView.getMeasuredHeight();
            }
        }

        setMeasuredDimension(parentWidth, parentHeight);
    }
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（2）onLayout（）方法

• 按照七列布局的設計，計算出每一個 item 的 left, top, right, bottom，精確地添加到控件裏

@Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        for (int i = 0; i < getChildCount(); i++) {
            View itemView = getChildAt(i);
            int columnCount = i % column;
            int rowCount = i / column;

            int itemWidth = itemView.getMeasuredWidth();
            int itemHeight = itemView.getMeasuredHeight();

            left = columnCount * itemWidth;
            top = rowCount * itemHeight;
            right = left + itemWidth;
            bottom = top + itemHeight;
            itemView.layout(left, top, right, bottom);
        }
    }
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（3）填充月份日期數據

• 暴露一個公共方法用於填充數據
• 根據傳進來的年、月，構建日期列表
• 逐一構建 itemView，填充到控件裏
• 調用requestLayout（）方法，從新繪製

public void setMonth(int year, int month) {
        mList = calendarUtils.getDaysListOfMonth(year, month);
        addAllItem();
        requestLayout();
    }

    private void addAllItem() {
        for (int i = 0; i < mList.size(); i++) {
            MyCalendarBean bean = mList.get(i);

            View itemView = generateDateView(bean);
            addViewInLayout(itemView, i, itemView.getLayoutParams(), true);
        }
    }

    private View generateDateView(MyCalendarBean bean) {
        View itemView = LayoutInflater.from(getContext()).inflate(R.layout.item_date_view, null);
        if (bean.isCurrentMonth()) {
            TextView date = itemView.findViewById(R.id.date);
            date.setText(String.valueOf(bean.getDay()));
        }
        return itemView;
    }
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把 item_date_view.xml 佈局也放出來

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:gravity="center"
        android:textSize="14sp"
        android:textColor="@color/text_black"
        />

</RelativeLayout>
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二、在佈局中使用

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@color/background_white"
    >

    <com.example.deesonwoo.mysimplecalendar.calendar.MonthCalendarView
        android:id="@+id/month_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/colorAccent">

    </com.example.deesonwoo.mysimplecalendar.calendar.MonthCalendarView>

</LinearLayout>

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三、在 MainActivity 中的使用

package com.example.deesonwoo.mysimplecalendar;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.example.deesonwoo.mysimplecalendar.calendar.MonthCalendarView;
import com.example.deesonwoo.mysimplecalendar.calendar.MyCalendarBean;
import com.example.deesonwoo.mysimplecalendar.calendar.MyCalendarUtils;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    MonthCalendarView monthView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        monthView = findViewById(R.id.month_view);
        initCalendar();
    }

    private void initCalendar() {
        //測試顯示2018年3月
        monthView.setMonth(2018, 3);
    }
}

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效果展現以下：

四、添加頂部周佈局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@color/background_white"
    >


    <LinearLayout
        android:id="@+id/week_layout"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:orientation="horizontal"
        android:background="@color/white"
        >

        <TextView
            android:id="@+id/week_00"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="週日"
            android:textColor="@color/text_black"
            android:textSize="12sp" />

        <TextView
            android:id="@+id/week_01"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="週一"
            android:textColor="@color/text_black"
            android:textSize="12sp" />

        <TextView
            android:id="@+id/week_02"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="週二"
            android:textColor="@color/text_black"
            android:textSize="12sp" />

        <TextView
            android:id="@+id/week_03"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="週三"
            android:textColor="@color/text_black"
            android:textSize="12sp" />

        <TextView
            android:id="@+id/week_04"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="週四"
            android:textColor="@color/text_black"
            android:textSize="12sp" />

        <TextView
            android:id="@+id/week_05"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="週五"
            android:textColor="@color/text_black"
            android:textSize="12sp" />

        <TextView
            android:id="@+id/week_06"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="週六"
            android:textColor="@color/text_black"
            android:textSize="12sp" />
    </LinearLayout>

    <com.example.deesonwoo.mysimplecalendar.calendar.MonthCalendarView
        android:id="@+id/month_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/colorAccent">

    </com.example.deesonwoo.mysimplecalendar.calendar.MonthCalendarView>

</LinearLayout>

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效果以下：

五、優化日期與星期的對應關係

相信大家已經發現，上面展現的效果中，日期與星期並無進行一一對應的排布。接下來，一塊兒咱們優化一下。

• 找到當前月份第一天對應的星期
• 修改工具類方法 getDaysListOfMonth（）， 將前面空缺的上一個月的日期填充到月份列表中
• 將上個月的日期隱藏

（1）在 MyCalendarUtils 工具類中添加下面「獲取具體一天對應的星期」的方法

/**
     * 獲取具體一天對應的星期
     *
     * @param year
     * @param month
     * @param day
     * @return 1-7(週日-週六)
     */
    private int getWeekDayOnCertainDate(int year, int month, int day) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month - 1, day);
        return calendar.get(Calendar.DAY_OF_WEEK);
    }
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（2）修改 getDaysListOfMonth（）方法，將前面空缺的上一個月的日期填充到月份列表中

/**
     * 獲取當前月份的日期列表
     *
     * @param year
     * @param month
     * @return
     */
    public List<MyCalendarBean> getDaysListOfMonth(int year, int month) {

        List<MyCalendarBean> list = new ArrayList<>();

        int daysOfMonth = getDaysOfCertainMonth(year, month);

        //找到當前月第一天的星期，計算出前面空缺的上個月的日期個數，填充到當月日期列表中
        int weekDayOfFirstDay = getWeekDayOnCertainDate(year, month, 1);
        int preMonthDays = weekDayOfFirstDay - 1;

        for (int i = preMonthDays; i > 0; i--) {
            MyCalendarBean preMonthBean = generateCalendarBean(year, month, 1 - i);
            list.add(preMonthBean);
        }

        for (int i = 0; i < daysOfMonth; i++) {
            MyCalendarBean monthBean = generateCalendarBean(year, month, i + 1);
            list.add(monthBean);
        }
        return list;
    }
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展現效果以下：

顯然，上一個月的日期在這裏是須要區別展現或者須要隱藏的，否則會給用戶形成視覺上的困擾，這裏，我直接作隱藏操做。

（3）給日期實體類增長當前月標識，isCurrentMonth，並在構建數據的時候給標識賦值。

實體類以下：

/**
 * Created by deeson.woo
 */
public class MyCalendarBean {

    private int year;
    private int month;//1-12
    private int day;//1-31
    private boolean isCurrentMonth = true;//是否爲當前月份的日期

    public MyCalendarBean(int year, int month, int day) {
        this.year = year;
        this.month = month;
        this.day = day;
    }

    public int getYear() {
        return year;
    }

    public int getMonth() {
        return month;
    }

    public int getDay() {
        return day;
    }

    public boolean isCurrentMonth() {
        return isCurrentMonth;
    }

    public void setCurrentMonth(boolean currentMonth) {
        isCurrentMonth = currentMonth;
    }
}
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給標識賦值，在 getDaysListOfMonth（）中賦值：

/**
     * 獲取當前月份的日期列表
     *
     * @param year
     * @param month
     * @return
     */
    public List<MyCalendarBean> getDaysListOfMonth(int year, int month) {

        List<MyCalendarBean> list = new ArrayList<>();

        int daysOfMonth = getDaysOfCertainMonth(year, month);

        //找到當前月第一天的星期，計算出前面空缺的上個月的日期個數，填充到當月日期列表中
        int weekDayOfFirstDay = getWeekDayOnCertainDate(year, month, 1);
        int preMonthDays = weekDayOfFirstDay - 1;

        for (int i = preMonthDays; i > 0; i--) {
            MyCalendarBean preMonthBean = generateCalendarBean(year, month, 1 - i);
            preMonthBean.setCurrentMonth(false);
            list.add(preMonthBean);
        }

        for (int i = 0; i < daysOfMonth; i++) {
            MyCalendarBean monthBean = generateCalendarBean(year, month, i + 1);
            monthBean.setCurrentMonth(true);
            list.add(monthBean);
        }
        return list;
    }
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最後修改咱們自定義月曆類中 generateDateView（）方法，不顯示上個月的日期：

private View generateDateView(MyCalendarBean bean) {
        View itemView = LayoutInflater.from(getContext()).inflate(R.layout.item_date_view, null);
        if(bean.isCurrentMonth()){
            TextView date = itemView.findViewById(R.id.date);
            date.setText(String.valueOf(bean.getDay()));
        }
        return itemView;
    }
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效果以下：

3、持續優化改進

一、將靜態日曆改爲動態可切換顯示

（1）添加頭部佈局，用於顯示當前月份以及翻頁

<RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/background_blue"
        >
        <TextView
            android:id="@+id/title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:textSize="20sp"
            android:textColor="@color/white"
            />

        <ImageView
            android:id="@+id/pre_month"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:layout_centerVertical="true"
            android:layout_alignParentLeft="true"
            android:src="@mipmap/btn_preview"
            />
        <ImageView
            android:id="@+id/next_month"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:layout_centerVertical="true"
            android:layout_alignParentRight="true"
            android:src="@mipmap/btn_next"
            />

    </RelativeLayout>
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#####（2）修改自定義月曆類

• 增長當前顯示的年月成員變量

private int mYear, mMonth;

• 修改構造方法和填充數據的方法

public MonthCalendarView(Context context) {
        super(context);
        calendarUtils = new MyCalendarUtils(context);
    }

    public MonthCalendarView(Context context, AttributeSet attrs) {
        super(context, attrs);
        calendarUtils = new MyCalendarUtils(context);
    }

    public void setMonth(int year, int month) {
        this.mYear = year;
        this.mMonth = month;
        invalidateMonth();
    }

    private void invalidateMonth() {
        mList = calendarUtils.getDaysListOfMonth(mYear, mMonth);
        removeAllViews();
        addAllItem();
        requestLayout();
    }
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• 增長前翻頁、後翻頁方法

/**
     * 展現上一個月
     */
    public void moveToPreMonth() {
        mMonth -= 1;
        invalidateMonth();
    }

    /**
     * 展現下一個月
     */
    public void moveToNextMonth() {
        mMonth += 1;
        invalidateMonth();
    }
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• 增長獲取當前顯示年月的方法

public String getCurrentYearAndMonth() {
        return MyCalendarUtils.formatYearAndMonth(mYear, mMonth);
    }
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（3）增長工具類方法

/**
     * 格式化標題展現
     * @param year
     * @param month
     * @return
     */
    public static String formatYearAndMonth(int year, int month) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month - 1, 1);
        year = calendar.get(Calendar.YEAR);
        month = calendar.get(Calendar.MONTH) + 1;
        return year + "年" + month + "月";
    }

    /**
     * 獲取系統當前年月日
     *
     * @return
     */
    public static int[] getNowDayFromSystem() {
        Calendar cal = Calendar.getInstance();
        cal.setTime(new Date());
        return new int[]{cal.get(Calendar.YEAR), cal.get(Calendar.MONTH) + 1, cal.get(Calendar.DATE)};
    }
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（4）修改 MainActivity 類

• 修改主題樣式
• 增長頭部佈局相關
• 默認顯示系統當前年月

package com.example.deesonwoo.mysimplecalendar;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.TextView;

import com.example.deesonwoo.mysimplecalendar.calendar.MonthCalendarView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    MonthCalendarView monthView;
    ImageView btnPreMonth, btnNextMonth;
    TextView title;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_main);
        monthView = findViewById(R.id.month_view);
        initCalendar();
        initTitleView();
        updateTitle();
    }

    private void initCalendar() {
        int[] nowDay = MyCalendarUtils.getNowDayFromSystem();
        monthView.setMonth(nowDay[0], nowDay[1]);
    }

    private void initTitleView() {
        title = findViewById(R.id.title);
        btnPreMonth = findViewById(R.id.pre_month);
        btnNextMonth = findViewById(R.id.next_month);
        btnPreMonth.setOnClickListener(this);
        btnNextMonth.setOnClickListener(this);
    }

    /**
     * 刷新標題顯示年月
     */
    private void updateTitle() {
        String yearAndMonth = monthView.getCurrentYearAndMonth();
        title.setText(yearAndMonth);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.pre_month:
                monthView.moveToPreMonth();
                updateTitle();
                break;
            case R.id.next_month:
                monthView.moveToNextMonth();
                updateTitle();
                break;
        }
    }
}
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最後顯示的效果以下動圖：

二、增長高亮顯示系統當天日期

• 增長工具類方法

/**
     * 判斷是否爲系統當天
     * @param bean
     * @return
     */
    public static boolean isToday(MyCalendarBean bean) {
        int[] nowDay = getNowDayFromSystem();
        return bean.getYear() == nowDay[0] && bean.getMonth() == nowDay[1] && bean.getDay() == nowDay[2];
    }
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• 修改自定義月曆類構建日期的方法

private View generateDateView(MyCalendarBean bean) {
        View itemView = LayoutInflater.from(getContext()).inflate(R.layout.item_date_view, null);
        if (bean.isCurrentMonth()) {
            TextView date = itemView.findViewById(R.id.date);
            if (MyCalendarUtils.isToday(bean)) {
                date.setBackgroundResource(R.drawable.item_today_bg);
            }
            date.setText(String.valueOf(bean.getDay()));
        }
        return itemView;
    }
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• 系統當天高亮顯示的背景 item_today_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <solid
        android:color="@color/theme_color" />

</shape>
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效果以下：

三、增長點擊日期效果

（1）修改自定義月曆類

• 修改構建日期方法

private View generateDateView(MyCalendarBean bean) {
        View itemView = LayoutInflater.from(getContext()).inflate(R.layout.item_date_view, null);
        if (bean.isCurrentMonth()) {
            TextView date = itemView.findViewById(R.id.date);
            if (MyCalendarUtils.isToday(bean)) {
                date.setBackgroundResource(R.drawable.item_today_bg);
            } else {
                date.setBackgroundResource(R.drawable.item_pick_up);
            }
            date.setText(String.valueOf(bean.getDay()));
        }
        return itemView;
    }
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• item_pick_up.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_selected="true">
        <shape android:shape="oval">
            <stroke android:color="@color/theme_color" android:width="1dp"/>
        </shape>
    </item>

    <item android:drawable="@android:color/transparent" />
</selector>
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• 增長在主界面點擊的回調接口方法

private OnDatePickUpListener onDatePickUpListener;

    public void setOnDatePickUpListener(OnDatePickUpListener onDatePickUpListener) {
        this.onDatePickUpListener = onDatePickUpListener;
    }

    public interface OnDatePickUpListener {
        void onDatePickUp(MyCalendarBean bean);
    }
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• 修改添加日期的方法，增長點擊監聽

private void addAllItem() {
        for (int i = 0; i < mList.size(); i++) {
            final MyCalendarBean bean = mList.get(i);

            final View itemView = generateDateView(bean);
            addViewInLayout(itemView, i, itemView.getLayoutParams(), true);
            final int position = i;
            itemView.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {

                    if (pickUpPosition == position) {
                        return;
                    }

                    if (pickUpPosition != -1) {
                        getChildAt(pickUpPosition).setSelected(false);
                    }
                    itemView.setSelected(true);

                    if (null != onDatePickUpListener) {
                        onDatePickUpListener.onOnDatePickUp(bean);
                    }

                    pickUpPosition = position;
                }
            });
        }
    }
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（2）在MainActivity中調用

private void initCalendar() {
        int[] nowDay = MyCalendarUtils.getNowDayFromSystem();
        monthView.setMonth(nowDay[0], nowDay[1]);
        monthView.setOnDatePickUpListener(new MonthCalendarView.OnDatePickUpListener() {
            @Override
            public void onDatePickUp(MyCalendarBean bean) {
                Toast.makeText(MainActivity.this, bean.toString(), Toast.LENGTH_SHORT).show();
            }
        });
    }
複製代碼

效果以下動圖：

4、整合自定義控件

你們可能以爲咱們的自定義控件到這裏就完結了，可是young、simple、naive......（瞎bb） 秉着高內聚低耦合的原則（再次瞎bb），我將剛剛出現的操做所有整合到一個控件SimpleCalendarView 中。 直接上代碼吧，也沒幾行，就不作什麼解釋了。

一、SimpleCalendarView 類

• 無非就是將標題視圖、星期視圖、月曆視圖逐一添加到自定義SimpleCalendarView 類中，再將相關接口補上，請看下面代碼

package com.example.deesonwoo.mysimplecalendar.calendar;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.example.deesonwoo.mysimplecalendar.R;


public class SimpleCalendarView extends LinearLayout implements View.OnClickListener, MonthCalendarView.OnDatePickUpListener {

    private MonthCalendarView monthCalendarView;// 月曆
    private OnDatePickListener onDatePickListener;

    private TextView title;

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

    public SimpleCalendarView(Context context, AttributeSet attrs) {
        super(context, attrs);

        setOrientation(VERTICAL);
        setBackgroundColor(context.getResources().getColor(R.color.white));

        // 年月標題、翻頁按鈕
        LayoutParams titleParams = new LayoutParams(LayoutParams.MATCH_PARENT, MyCalendarUtils.dp2px(context, 50));
        RelativeLayout titleLayout = (RelativeLayout) LayoutInflater.from(context).inflate(R.layout.title_layout, null);
        title = titleLayout.findViewById(R.id.title);
        ImageView preMonth = titleLayout.findViewById(R.id.pre_month);
        ImageView nextMonth = titleLayout.findViewById(R.id.next_month);
        preMonth.setOnClickListener(this);
        nextMonth.setOnClickListener(this);
        addView(titleLayout, titleParams);

        //星期佈局
        LayoutParams weekParams = new LayoutParams(LayoutParams.MATCH_PARENT, MyCalendarUtils.dp2px(context, 40));
        LinearLayout weekLayout = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.week_layout, null);
        addView(weekLayout, weekParams);

        //月曆視圖
        LayoutParams monthParams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
        monthCalendarView = new MonthCalendarView(context);
        initCalendarDate();
        monthCalendarView.setOnDatePickUpListener(this);
        addView(monthCalendarView, monthParams);
    }

    private void initCalendarDate() {
        int[] nowDay = MyCalendarUtils.getNowDayFromSystem();
        monthCalendarView.setMonth(nowDay[0], nowDay[1]);
        updateTitle();
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.pre_month:
                if (null != monthCalendarView) {
                    monthCalendarView.moveToPreMonth();
                }
                updateTitle();
                break;
            case R.id.next_month:
                if (null != monthCalendarView) {
                    monthCalendarView.moveToNextMonth();
                }
                updateTitle();
                break;
        }
    }

    private void updateTitle() {
        if (null != title && null != monthCalendarView) {
            title.setText(monthCalendarView.getCurrentYearAndMonth());
        }
    }

    @Override
    public void onDatePickUp(MyCalendarBean bean) {
        if (null != onDatePickListener) {
            onDatePickListener.onDatePick(bean);
        }
    }

    public void setOnDatePickListener(OnDatePickListener onDatePickListener) {
        this.onDatePickListener = onDatePickListener;
    }

    public interface OnDatePickListener {
        void onDatePick(MyCalendarBean bean);
    }
}
複製代碼

二、在佈局中使用，很是簡單

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/background_white"
    android:orientation="vertical">

    <com.example.deesonwoo.mysimplecalendar.calendar.SimpleCalendarView
        android:id="@+id/calendarView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </com.example.deesonwoo.mysimplecalendar.calendar.SimpleCalendarView>

</LinearLayout>
複製代碼

三、在MainActivity 中調用

package com.example.deesonwoo.mysimplecalendar;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;

import com.example.deesonwoo.mysimplecalendar.calendar.MyCalendarBean;
import com.example.deesonwoo.mysimplecalendar.calendar.SimpleCalendarView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_main);

        SimpleCalendarView calendarView = findViewById(R.id.calendarView);
        calendarView.setOnDatePickListener(new SimpleCalendarView.OnDatePickListener() {
            @Override
            public void onDatePick(MyCalendarBean bean) {
                Toast.makeText(MainActivity.this, bean.toString(), Toast.LENGTH_SHORT).show();
            }
        });
    }
}
複製代碼

最後的效果就是文章開頭的動態圖。

5、後續

• 還有不少能夠擴展修改的地方，這裏就留給你們去作吧。
• 源碼連接在這裏