Android日历控件的实现方法

public class SelectDateDialog {
private static final String TAG = "SelectDateDialog";
private Dialog dialog;
private TextView dateText;
private int selectYear, selectMonth;
private AppCompatActivity mContext;
private DateAdapter adapter;
private List<String  selWeekList = new ArrayList< ();
private List<DateBean  list = new ArrayList< ();
public SelectDateDialog builder(AppCompatActivity mContext, int year, int month) {
this.mContext = mContext;
this.selectYear = year;
this.selectMonth = month;
// 获取Dialog布局
View view = LayoutInflater.from(mContext).inflate(R.layout.dialog_date, null);
// 定义Dialog布局和参数
dialog = new Dialog(mContext, R.style.AlertDialogStyle);
dialog.setCanceledOnTouchOutside(false);//点击外部是否取消
dialog.setCancelable(false);
dialog.setContentView(view);
Window window = dialog.getWindow();
WindowManager.LayoutParams params = window.getAttributes();
params.width = (ScreenUtils.getScreenWidth(mContext));
// params.height = (int) (ScreenUtils.getScreenHeight(mContext) * 0.5);
window.setAttributes(params);
window.setGravity(Gravity.BOTTOM);
RecyclerView recycler = view.findViewById(R.id.recycler_select_date);
dateText = view.findViewById(R.id.date_text);
dateText.setText(year + "年" + month + "月");
//下个月
view.findViewById(R.id.next_month).setOnClickListener(view13 -  {
if (selectMonth   11) {
selectYear = selectYear + 1;
selectMonth = 1;
} else {
selectMonth++;
}
showNewData(selectYear, selectMonth);
});
//上个月
view.findViewById(R.id.last_month).setOnClickListener(view14 -  {
if (selectMonth < 2) {
selectYear = selectYear - 1;
selectMonth = 12;
} else {
selectMonth--;
}
showNewData(selectYear, selectMonth);
});
list = DataUtils.getCalendar(year, month);
adapter = new DateAdapter(mContext, list);
GridLayoutManager manager = new GridLayoutManager(mContext, 7);
recycler.setLayoutManager(manager);
recycler.setAdapter(adapter);
//取消
view.findViewById(R.id.middle_cancel).setOnClickListener(view1 -  {
dialog.dismiss();
});
//确定
view.findViewById(R.id.middle_determine).setOnClickListener(view1 -  {
initSelect();
});
//设置选中当天
adapter.setNowDay(year, month, DataUtils.getLastMonth(year, month));
return this;
}
private void showNewData(int year, int month) {
list = DataUtils.getCalendar(year, month);
//更新月数据
adapter.setList(list);
adapter.setNowDay(year , month, DataUtils.getLastMonth(year, month));
dateText.setText(year + "年" + month + "月");
}
/**
* 获取选中的日期
*/
private void initSelect() {
selWeekList.clear();
for (int i = 0; i < list.size(); i++) {
if (list.get(i).isFlag()) {
//记录数量
selWeekList.add(selectYear + "-" + selectMonth + "-" + list.get(i).getWeek());
}
}
Log.e(TAG, "initSelect: "+ list.size());
Log.e(TAG, "initSelect: "+ selWeekList.size());
if (selWeekList.size() == 0) {
Toast.makeText(mContext, "未选则日期", Toast.LENGTH_SHORT).show();
return;
}
dialog.dismiss();
listener.date(DataUtils.returnList(selWeekList));
Log.e(TAG, "initSelect: " + DataUtils.returnList(selWeekList));
}
public void show() {
if (dialog != null && (!dialog.isShowing())) {
dialog.show();
}
}
private OnDateListener listener;
public SelectDateDialog setListener(OnDateListener listener) {
this.listener = listener;
return this;
}
public interface OnDateListener {
void date(String selectDate);
}
}

public class ScreenUtils {
public static int getScreenWidth(Context context) {
DisplayMetrics localDisplayMetrics = new DisplayMetrics();
((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(localDisplayMetrics);
return localDisplayMetrics.widthPixels;
}
}

public class DateBean {
private int week;
private boolean sign;
//0 上月 1本月 2下月
private int month;
private boolean isFlag;
public boolean isFlag() {
return isFlag;
}
public void setFlag(boolean flag) {
isFlag = flag;
}
public int getWeek() {
return week;
}
public void setWeek(int week) {
this.week = week;
}
public boolean isSign() {
return sign;
}
public void setSign(boolean sign) {
this.sign = sign;
}
public int getMonth() {
return month;
}
public void setMonth(int month) {
this.month = month;
}
public DateBean(int week, boolean sign, int month) {
this.week = week;
this.sign = sign;
this.month = month;
}
}

public class DateAdapter extends CommonRecyclerAdapter<DateBean  {
private static final String TAG = "DateAdapter";
private Integer nowDay;
private int year;
private int month;
public DateAdapter(Context context, List<DateBean  list) {
super(context, R.layout.item_date, list);
}
public void setNowDay(int year, int month, int nowDay) {
this.nowDay = nowDay;
this.year = year;
this.month = month;
notifyDataSetChanged();
}
@Override
public void convert(RecyclerHolder holder, DateBean item, int position) {
TextView number = holder.getView(R.id.item_number);
number.setText(item.getWeek() + "");
//当前年月等于切换年月时才选中当天
if (position == nowDay) {
String date = year + "-" + month;
if (date.equals(DataUtils.timeInMillsTrasToDate(1))) {
number.setBackgroundResource(R.drawable.date_unsel_shape);
number.setTextColor(Color.WHITE);
}else {
number.setTextColor(Color.parseColor("#333333"));
}
} else {
number.setBackgroundResource(0);
number.setTextColor(Color.parseColor("#333333"));
if (item.getMonth() == 0 || item.getMonth() == 2) {
number.setTextColor(Color.parseColor("#CDCDCD"));
} else {
number.setTextColor(Color.parseColor("#333333"));
}
}
//点击事件
number.setOnClickListener(view -  {
//本月可以点击
int nowYear = Integer.parseInt(DataUtils.timeInMillsTrasToDate(2));
int nowMonth = Integer.parseInt(DataUtils.timeInMillsTrasToDate(3));
//只有在今天之后的日期才可以选中
if (year == nowYear) {
if (item.getMonth() == 1 && month == nowMonth && position   nowDay) {
onClick(item, number);
} else if (month   nowMonth) {
onClick(item, number);
}
} else if (year   nowYear) {
onClick(item, number);
}
});
}
private void onClick(DateBean item, TextView number) {
if (item.isFlag()) {
item.setFlag(false);
number.setBackgroundResource(0);
number.setTextColor(Color.parseColor("#333333"));
} else {
item.setFlag(true);
number.setBackgroundResource(R.drawable.date_sel_shape);
number.setTextColor(Color.WHITE);
}
}
}

public class DataUtils {
private static final String TAG = "DataUtils";
/**
* 日历
*/
public static List<DateBean  getCalendar(int currentYear, int currentMonth) {
//实例化集合
List<DateBean  list = new ArrayList< ();
Calendar c = Calendar.getInstance();
c.clear();
/**
* 处理上个月月末
*/
if (currentMonth - 1 == 0) {
c.set(Calendar.YEAR, currentYear - 1);
c.set(Calendar.MONTH, 11);
} else {
c.set(Calendar.YEAR, currentYear);
c.set(Calendar.MONTH, (currentMonth - 2));
}
int last_sumDays = c.getActualMaximum(Calendar.DAY_OF_MONTH);
c.set(Calendar.DATE, last_sumDays);
//得到一号星期几
int weekDay = c.get(Calendar.DAY_OF_WEEK);
if (weekDay < 7) {
for (int i = weekDay - 1; i  = 0; i--) {
Integer date = new Integer(last_sumDays - i);
list.add(new DateBean(date, true, 0));
}
}
/**
* 处理当前月
*/
c.clear();
c.set(Calendar.YEAR, currentYear);
c.set(Calendar.MONTH, currentMonth - 1);
int currentsumDays = c.getActualMaximum(Calendar.DAY_OF_MONTH);
for (int i = 1; i <= currentsumDays; i++) {
Integer date = new Integer(i);
list.add(new DateBean(date, true, 1));
}
/**
* 处理下个月月初
*/
c.clear();
if (currentMonth == 12) {
c.set(Calendar.YEAR, currentYear + 1);
c.set(Calendar.MONTH, 0);
} else {
c.set(Calendar.YEAR, currentYear);
c.set(Calendar.MONTH, currentMonth);
}
c.set(Calendar.DATE, 1);
int currentWeekDay = c.get(Calendar.DAY_OF_WEEK);
if (currentWeekDay   2 && currentWeekDay < 8) {
for (int i = 1; i <= 8 - currentWeekDay; i++) {
list.add(new DateBean(i, true, 2));
}
}
return list;
}
/**
* 获取上个月大小
*/
public static Integer getLastMonth(int currentYear, int currentMonth) {
//实例化集合
List<Integer  list = new ArrayList< ();
Calendar c = Calendar.getInstance();
c.clear();
/**
* 处理上个月月末
*/
if (currentMonth - 1 == 0) {
c.set(Calendar.YEAR, currentYear - 1);
c.set(Calendar.MONTH, 11);
} else {
c.set(Calendar.YEAR, currentYear);
c.set(Calendar.MONTH, (currentMonth - 2));
}
int last_sumDays = c.getActualMaximum(Calendar.DAY_OF_MONTH);
c.set(Calendar.DATE, last_sumDays);
//得到一号星期几
int weekDay = c.get(Calendar.DAY_OF_WEEK);
if (weekDay < 7) {
for (int i = weekDay - 1; i  = 0; i--) {
list.add(i);
}
}
Log.e(TAG, "getLastMonth: " + Integer.parseInt(timeInMillsTrasToDate(0)));
return list.size() + Integer.parseInt(timeInMillsTrasToDate(0)) - 1;
}
/**
* list转string字符串
*/
public static String returnList(List<String  list) {
if (null == list && list.size() == 0) {
return "";
} else {
//去除空格
String str = String.valueOf(list).replaceAll(" ", "");
return str.substring(1, str.length() - 1);
}
}
/**
* 时间转换
*/
@TargetApi(Build.VERSION_CODES.N)
public static String timeInMillsTrasToDate(int formatType) {
DateFormat formatter = null;
switch (formatType) {
case 0:
formatter = new SimpleDateFormat("dd");
break;
case 1:
formatter = new SimpleDateFormat("yyyy-MM");
break;
case 2:
formatter = new SimpleDateFormat("yyyy");
break;
case 3:
formatter = new SimpleDateFormat("MM");
break;
}
Calendar calendar = Calendar.getInstance();
return formatter.format(calendar.getTime());
}
}

public class DateActivity extends AppCompatActivity {
private Button openDate;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_date);
openDate = this.findViewById(R.id.open_date);
openDate.setOnClickListener(view -  {
showDateDialog();
});
}
private void showDateDialog() {
int year = Integer.parseInt(DataUtils.timeInMillsTrasToDate(2));
int month = Integer.parseInt(DataUtils.timeInMillsTrasToDate(3));
new SelectDateDialog().builder(this, year, month)
.setListener(selectDate -  openDate.setText(selectDate)).show();
}
}

<?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" 
<Button
android:id="@+id/open_date"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="打开日历" / 
</LinearLayout 

<?xml version="1.0" encoding="utf-8"? 
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval"
android:useLevel="false" 
<solid android:color="@color/colorAccent" / 
<!--<stroke android:width="1dp" android:color="@color/white"/ -- 
<size
android:width="30dp"
android:height="30dp" / 
</shape 

<?xml version="1.0" encoding="utf-8"? 
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval"
android:useLevel="false" 
<solid android:color="@color/colorPrimary" / 
<!--<stroke android:width="1dp" android:color="@color/white"/ -- 
<size
android:width="30dp"
android:height="30dp" / 
</shape 

<?xml version="1.0" encoding="utf-8"? 
<shape xmlns:android="http://schemas.android.com/apk/res/android" 
<corners android:radius="5dp" / 
<solid android:color="#ffffff" / 
</shape 

<?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="wrap_content"
android:gravity="center"
android:padding="5dp" 
<TextView
android:id="@+id/item_number"
android:layout_width="35dp"
android:layout_height="35dp"
android:gravity="center"
android:text="10"
android:textSize="15sp" / 
</LinearLayout 

<color name="colorPrimary" #008577</color 
<color name="colorPrimaryDark" #00574B</color 
<color name="colorAccent" #D81B60</color 

<style name="AlertDialogStyle" parent="@android:style/Theme.Dialog" 
<item name="android:windowBackground" @android:color/transparent</item 
<item name="android:windowContentOverlay" @null</item 
<item name="android:windowIsFloating" true</item 
<item name="android:windowFrame" @null</item 
<item name="android:backgroundDimEnabled" true</item 
<item name="android:windowNoTitle" true</item 
<item name="android:windowIsTranslucent" true</item 
</style