安卓开发入门基础之日期视图与日期选择器+多线程时间简单设计移动开发无痕坚守本心的博客-

styles.xml

• 往styles.xml里添加下面的主题格式，改变日期视图字体颜色与选中的颜色

<style name="CalenderViewDateCustomText" parent="android:TextAppearance.DeviceDefault.Small">     <item name="android:textColor">@android:color/black</item>     <item name="android:weekNumberColor">@android:color/holo_blue_light</item> </style> <style name="CalenderViewWeekCustomText" parent="android:TextAppearance.DeviceDefault.Small">     <item name="android:textColor">@android:color/holo_blue_dark</item> </style>

calendarview.xml布局构思

• 日期视图的xml总体是一个垂直线性布局
• 里面放1个Textview文本,1个日期视图CalendarView，1个Button按钮

<CalendarView android:id="@+id/calendarview" android:theme="@style/CalenderViewCustom" android:dateTextAppearance="@style/CalenderViewDateCustomText" android:weekDayTextAppearance="@style/CalenderViewWeekCustomText" android:layout_width="match_parent" android:layout_height="300dp" android:layout_marginTop="70dp" />

calendarview.java

• 获取到的时间需要+8才能得到当前的北京时间

public class calendarview extends AppCompatActivity { private Button dingwei; private CalendarView calendarview; private TextView text1; private String date; private String date2;     Handler1 handler1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.calendarview);                  calendarview = findViewById(R.id.calendarview); final SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");          format.setTimeZone(TimeZone.getTimeZone("GMT+08:00"));          date = format.format(calendarview.getDate());          text1 = findViewById(R.id.text);         handler1 =new Handler1();         Thread1 thread1 =new Thread1();         thread1.start();          calendarview.setOnDateChangeListener(new CalendarView.OnDateChangeListener() { @Override public void onSelectedDayChange(@NonNull CalendarView calendarView, int i, int i1, int i2) {                  date2 = i + "年" + (i1 + 1) + "月" + i2 + "日"; if (date2.equals("2020年4月13日")) {                     Toast.makeText(getApplicationContext(), "  您选择的时间是今天 ~~~ "+ date2, Toast.LENGTH_SHORT).show();                     dingwei.setVisibility(View.GONE); } else {                     dingwei.setVisibility(View.VISIBLE);                     Toast.makeText(getApplicationContext(), "您手动选择的时间是:  " + date2 , Toast.LENGTH_SHORT).show(); } } });          dingwei = view.findViewById(R.id.dingwei);         dingwei.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) {                 Toast.makeText(getApplicationContext(), "当前时间是:  " + getTime(), Toast.LENGTH_SHORT).show(); } }); return view; } //获得当前年月日时分秒星期 public String getTime(){ final Calendar c = Calendar.getInstance();         c.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));         String mYear = String.valueOf(c.get(Calendar.YEAR)); // 获取当前年份         String mMonth = String.valueOf(c.get(Calendar.MONTH) + 1);// 获取当前月份         String mDay = String.valueOf(c.get(Calendar.DAY_OF_MONTH));// 获取当前月份的日期号码         String mWay = String.valueOf(c.get(Calendar.DAY_OF_WEEK));         String mHour = String.valueOf(c.get(Calendar.HOUR_OF_DAY));//时         String mMinute = String.valueOf(c.get(Calendar.MINUTE));//分         String mSecond = String.valueOf(c.get(Calendar.SECOND));//秒 if("1".equals(mWay)){             mWay ="日"; }else if("2".equals(mWay)){             mWay ="一"; }else if("3".equals(mWay)){             mWay ="二"; }else if("4".equals(mWay)){             mWay ="三"; }else if("5".equals(mWay)){             mWay ="四"; }else if("6".equals(mWay)){             mWay ="五"; }else if("7".equals(mWay)){             mWay ="六"; } return mYear + "-" + mMonth + "-" + mDay+"  "+"星期"+ mWay +"  "+mHour+":"+mMinute+":"+mSecond; } class Handler1 extends android.os.Handler{ @Override public void handleMessage(Message msg){ switch (msg.what){ case 0x8f:                     text1.setText("  当前时间为： " + getTime()); } } } class Thread1 extends Thread{ @Override public void run(){ for (int i=1;i<=1000000000;i++){                 Message message =new Message();                 message.what = 0x8f;                 message.arg1 = i;                 handler1.sendMessage(message); try {                     Thread1.sleep(1000); }catch (InterruptedException e){                     e.printStackTrace(); } } } } } 

设计效果图

• 刚进入的界面

• 点击别的时间弹出提示与隐藏按钮

• 点击 当前时间 按钮
  
• 点击当前日期弹出提示

datepicker.xml

• 日期选择器的xml总体是一个垂直线性布局
• 里面放了1个日期选择器datepicker，1个Button按钮

<DatePicker android:layout_marginTop="100dp" android:theme="@style/DatePickerViewCustom" android:dateTextAppearance="@style/CalenderViewDateCustomText" android:weekDayTextAppearance="@style/CalenderViewWeekCustomText" android:id="@+id/dataPicker" android:layout_width="wrap_content" android:layout_height="wrap_content"/>

Styles.xml

• 往styles.xml里添加下面的主题格式，改变日期选择题头部字体颜色

<style name="DatePickerViewCustom" parent="Theme.AppCompat.DayNight.Dialog">     <item name="android:textColor">@android:color/darker_gray</item>     <item name="android:weekNumberColor">@android:color/holo_blue_bright</item> </style>

datepicker.java

• 主要实现在datepicker里选择日期以及回到今天的操作

public class datepicker extends AppCompatActivity { private DatePicker datapicker;     String date; private Button button; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.setting);         datapicker = findViewById(R.id.dataPicker);         Calendar calendar = Calendar.getInstance(); final int year = calendar.get(Calendar.YEAR); final int month = calendar.get(Calendar.MONTH); final int dayofmonth = calendar.get(Calendar.DAY_OF_MONTH);          datapicker.init(year, month, dayofmonth, new DatePicker.OnDateChangedListener() { @Override public void onDateChanged(DatePicker datePicker, int i, int i1, int i2) {                 date = i + "年" + (i1 + 1) + "月" + i2 + "日"; if (date.equals("2020年4月13日")) {                     button.setVisibility(View.GONE);                     Toast.makeText(getApplicationContext(), "  您选择的时间是今天 ~~~ " + date, Toast.LENGTH_SHORT).show(); } else {                     button.setVisibility(View.VISIBLE);                     Toast.makeText(getApplicationContext(), date, Toast.LENGTH_SHORT).show(); } } });          button = findViewById(R.id.button);         button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) {                  button.setVisibility(View.GONE);                 datapicker.init(year, month, dayofmonth, new DatePicker.OnDateChangedListener() { @Override public void onDateChanged(DatePicker datePicker, int i, int i1, int i2) {                          date = i + "年" + (i1 + 1) + "月" + i2 + "日"; if (date.equals("2020年4月13日")) {                             button.setVisibility(View.GONE);                             Toast.makeText(getApplicationContext(), "  您选择的时间是今天 ~~~ " + date, Toast.LENGTH_SHORT).show(); } else {                             button.setVisibility(View.VISIBLE);                             Toast.makeText(getApplicationContext(), date, Toast.LENGTH_SHORT).show(); } } }); } }); } }

设计效果图

• 博主用了fragment作为APP开发的基本框架，后续会写到这个用法，纯粹是为了达到简洁美观的效果
• 刚进去的界面

• 点击当前设置的日期弹出提示
  
• 点击别的日期，出现 回到今天 的按钮，并且弹出当前日期

• 准备点击回到今天按钮

• 点击回到今天按钮后跳回当前设置的日期