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src/net/micode/notes/ui/DateTimePicker.java

@@ -28,42 +28,67 @@ import android.view.View;
 import android.widget.FrameLayout;
 import android.widget.NumberPicker;
 
+//自定义的日期时间选择器控件，继承自FrameLayout。
 public class DateTimePicker extends FrameLayout {
 
+    //默认的启用状态
     private static final boolean DEFAULT_ENABLE_STATE = true;
 
+    //一天中的小时数(半天和全天)
     private static final int HOURS_IN_HALF_DAY = 12;
     private static final int HOURS_IN_ALL_DAY = 24;
+
+    //一周当中的天数
     private static final int DAYS_IN_ALL_WEEK = 7;
+
+    //根据一周的天数设置日期选择器(NumberPicker)的最大和最小值
     private static final int DATE_SPINNER_MIN_VAL = 0;
     private static final int DATE_SPINNER_MAX_VAL = DAYS_IN_ALL_WEEK - 1;
+
+    //定义24小时视图中小时选择器的最大和最小值
     private static final int HOUR_SPINNER_MIN_VAL_24_HOUR_VIEW = 0;
     private static final int HOUR_SPINNER_MAX_VAL_24_HOUR_VIEW = 23;
+
+    //定义12小时视图中小时选择器的最大和最小值
     private static final int HOUR_SPINNER_MIN_VAL_12_HOUR_VIEW = 1;
     private static final int HOUR_SPINNER_MAX_VAL_12_HOUR_VIEW = 12;
+
+    //分钟选择器的最大和最小值
     private static final int MINUT_SPINNER_MIN_VAL = 0;
     private static final int MINUT_SPINNER_MAX_VAL = 59;
+
+    //AM/PM 选择器的最大和最小值
     private static final int AMPM_SPINNER_MIN_VAL = 0;
     private static final int AMPM_SPINNER_MAX_VAL = 1;
 
+    //NumberPicker 控件的实例引用
     private final NumberPicker mDateSpinner;
     private final NumberPicker mHourSpinner;
     private final NumberPicker mMinuteSpinner;
     private final NumberPicker mAmPmSpinner;
+
+    //用于存储和处理日期的Calendar实例
     private Calendar mDate;
 
+    //日期显示的数据，用于存储一周内每一天的描述
     private String[] mDateDisplayValues = new String[DAYS_IN_ALL_WEEK];
 
+    //是否为上午的变量
     private boolean mIsAm;
 
+    //是否为24小时视图的标志变量
     private boolean mIs24HourView;
 
+    //控件的启用状态
     private boolean mIsEnabled = DEFAULT_ENABLE_STATE;
 
+    //是否正在初始化的标志变量，避免在初始化过程中触发事件
     private boolean mInitialising;
 
+    //日期变化监听器接口，用于在日期时间改变时通知用户
     private OnDateTimeChangedListener mOnDateTimeChangedListener;
 
+    //日期改变监听器
     private NumberPicker.OnValueChangeListener mOnDateChangedListener = new NumberPicker.OnValueChangeListener() {
         @Override
         public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
@@ -73,6 +98,7 @@ public class DateTimePicker extends FrameLayout {
         }
     };
 
+    //小时改变监听器
     private NumberPicker.OnValueChangeListener mOnHourChangedListener = new NumberPicker.OnValueChangeListener() {
         @Override
         public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
@@ -115,6 +141,7 @@ public class DateTimePicker extends FrameLayout {
         }
     };
 
+    //分钟改变监听器
     private NumberPicker.OnValueChangeListener mOnMinuteChangedListener = new NumberPicker.OnValueChangeListener() {
         @Override
         public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
@@ -144,6 +171,7 @@ public class DateTimePicker extends FrameLayout {
         }
     };
 
+    //AM/PM 改变监听器
     private NumberPicker.OnValueChangeListener mOnAmPmChangedListener = new NumberPicker.OnValueChangeListener() {
         @Override
         public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
@@ -158,24 +186,30 @@ public class DateTimePicker extends FrameLayout {
         }
     };
 
+    //日期时间变化的监听器接口，需要被实现来响应日期时间的任何变化
     public interface OnDateTimeChangedListener {
         void onDateTimeChanged(DateTimePicker view, int year, int month,
                 int dayOfMonth, int hourOfDay, int minute);
     }
 
+    //构造器1：当没有指定日期时，默认使用当前的系统时间
     public DateTimePicker(Context context) {
         this(context, System.currentTimeMillis());
     }
 
+    //构造器2：允许在创建控件时指定一个日期
     public DateTimePicker(Context context, long date) {
         this(context, date, DateFormat.is24HourFormat(context));
     }
 
+    //构造器3：最完整的构造器，允许指定日期和是否以24小时格式显示时间
     public DateTimePicker(Context context, long date, boolean is24HourView) {
-        super(context);
+        super(context); //调用父类构造器
-        mDate = Calendar.getInstance();
+        mDate = Calendar.getInstance(); //初始化当前日期和时间的日历实例
-        mInitialising = true;
+        mInitialising = true; //开始初始化流程的标志
+        //设置是否用上午/下午模式还是24小时制
         mIsAm = getCurrentHourOfDay() >= HOURS_IN_HALF_DAY;
+        //通过XML布局文件创建视图
         inflate(context, R.layout.datetime_picker, this);
 
         mDateSpinner = (NumberPicker) findViewById(R.id.date);
@@ -203,17 +237,20 @@ public class DateTimePicker extends FrameLayout {
         updateHourControl();
         updateAmPmControl();
 
+        //更新24小时播放视图
         set24HourView(is24HourView);
 
-        // set to current time
+        // set to current time设置当前日期到指定的时间
         setCurrentDate(date);
 
+        //更新控件的启用状态
         setEnabled(isEnabled());
 
-        // set the content descriptions
+        // set the content descriptions 设置内容描述
-        mInitialising = false;
+        mInitialising = false; //初始化完成
     }
 
+    //设置控件是否可用，并且使内部的NumberPicker控件与之匹配
     @Override
     public void setEnabled(boolean enabled) {
         if (mIsEnabled == enabled) {
@@ -227,6 +264,7 @@ public class DateTimePicker extends FrameLayout {
         mIsEnabled = enabled;
     }
 
+    //检查控件是否可以与用户交互
     @Override
     public boolean isEnabled() {
         return mIsEnabled;
@@ -237,6 +275,8 @@ public class DateTimePicker extends FrameLayout {
      *
      * @return the current date in millis
      */
+
+    //获取当前的日期及时间
     public long getCurrentDateInTimeMillis() {
         return mDate.getTimeInMillis();
     }
@@ -246,6 +286,8 @@ public class DateTimePicker extends FrameLayout {
      *
      * @param date The current date in millis
      */
+
+    //设置当前日期和时间
     public void setCurrentDate(long date) {
         Calendar cal = Calendar.getInstance();
         cal.setTimeInMillis(date);
@@ -262,6 +304,8 @@ public class DateTimePicker extends FrameLayout {
      * @param hourOfDay The current hourOfDay
      * @param minute The current minute
      */
+
+    //设置具体的日期和时间
     public void setCurrentDate(int year, int month,
             int dayOfMonth, int hourOfDay, int minute) {
         setCurrentYear(year);
@@ -276,6 +320,8 @@ public class DateTimePicker extends FrameLayout {
      *
      * @return The current year
      */
+
+    //获取和设置当前的年份
     public int getCurrentYear() {
         return mDate.get(Calendar.YEAR);
     }
@@ -299,6 +345,8 @@ public class DateTimePicker extends FrameLayout {
      *
      * @return The current month in the year
      */
+
+    //获取和设置当前的月份
     public int getCurrentMonth() {
         return mDate.get(Calendar.MONTH);
     }
@@ -322,6 +370,8 @@ public class DateTimePicker extends FrameLayout {
      *
      * @return The day of the month
      */
+
+    //获取和设置当前的日期(天)
     public int getCurrentDay() {
         return mDate.get(Calendar.DAY_OF_MONTH);
     }
@@ -344,6 +394,8 @@ public class DateTimePicker extends FrameLayout {
      * Get current hour in 24 hour mode, in the range (0~23)
      * @return The current hour in 24 hour mode
      */
+
+    //获取和设置当前的小时(24时制)
     public int getCurrentHourOfDay() {
         return mDate.get(Calendar.HOUR_OF_DAY);
     }
@@ -394,6 +446,8 @@ public class DateTimePicker extends FrameLayout {
      *
      * @return The Current Minute
      */
+
+    //获取和设置当前的分钟数
     public int getCurrentMinute() {
         return mDate.get(Calendar.MINUTE);
     }
@@ -413,6 +467,8 @@ public class DateTimePicker extends FrameLayout {
     /**
      * @return true if this is in 24 hour view else false.
      */
+
+    //判断是否为24小时格式
     public boolean is24HourView () {
         return mIs24HourView;
     }
@@ -422,6 +478,8 @@ public class DateTimePicker extends FrameLayout {
      *
      * @param is24HourView True for 24 hour mode. False for AM/PM mode.
      */
+
+    //设置为24小时格式或者 AM/PM格式
     public void set24HourView(boolean is24HourView) {
         if (mIs24HourView == is24HourView) {
             return;
@@ -434,37 +492,40 @@ public class DateTimePicker extends FrameLayout {
         updateAmPmControl();
     }
 
+    //更新日期显示控制，以供日历滚动操作时显示正确日期
     private void updateDateControl() {
-        Calendar cal = Calendar.getInstance();
+        Calendar cal = Calendar.getInstance(); //获取当前日期的日历实例
-        cal.setTimeInMillis(mDate.getTimeInMillis());
+        cal.setTimeInMillis(mDate.getTimeInMillis()); //设置日历时间为当前控件已选择的时间
-        cal.add(Calendar.DAY_OF_YEAR, -DAYS_IN_ALL_WEEK / 2 - 1);
+        cal.add(Calendar.DAY_OF_YEAR, -DAYS_IN_ALL_WEEK / 2 - 1); //将日历日期向后调整以便在选择器中心显示
-        mDateSpinner.setDisplayedValues(null);
+        mDateSpinner.setDisplayedValues(null); //清除显示值
         for (int i = 0; i < DAYS_IN_ALL_WEEK; ++i) {
-            cal.add(Calendar.DAY_OF_YEAR, 1);
+            cal.add(Calendar.DAY_OF_YEAR, 1); //为日期数组的每一天累加一天
             mDateDisplayValues[i] = (String) DateFormat.format("MM.dd EEEE", cal);
         }
-        mDateSpinner.setDisplayedValues(mDateDisplayValues);
+        mDateSpinner.setDisplayedValues(mDateDisplayValues); //设置日期选择器显示值为新的日期列表
-        mDateSpinner.setValue(DAYS_IN_ALL_WEEK / 2);
+        mDateSpinner.setValue(DAYS_IN_ALL_WEEK / 2); //设置选择器的当前值为中间的日期
-        mDateSpinner.invalidate();
+        mDateSpinner.invalidate(); //刷新视图状态
     }
 
+    //更新AM/PM显示控制，以显示或隐藏AM/PM选择器，具体取决于是否采用24小时视图
     private void updateAmPmControl() {
         if (mIs24HourView) {
-            mAmPmSpinner.setVisibility(View.GONE);
+            mAmPmSpinner.setVisibility(View.GONE); //如果是24小时制，则隐藏AM/PM选择器
         } else {
-            int index = mIsAm ? Calendar.AM : Calendar.PM;
+            int index = mIsAm ? Calendar.AM : Calendar.PM; //确定当前是上午还是下午
-            mAmPmSpinner.setValue(index);
+            mAmPmSpinner.setValue(index); //设置AM/PM选择器值为当前AM或者PM
-            mAmPmSpinner.setVisibility(View.VISIBLE);
+            mAmPmSpinner.setVisibility(View.VISIBLE); //显示AM/PM选择器
         }
     }
 
+    //更新小时显示控制，调整小时选择器的最小和最大值，以匹配所选择的24小时制或12小时制
     private void updateHourControl() {
         if (mIs24HourView) {
-            mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_24_HOUR_VIEW);
+            mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_24_HOUR_VIEW); //如果24，则小时选择器最小值设置为0/1
-            mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_24_HOUR_VIEW);
+            mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_24_HOUR_VIEW); //小时选择器的最大值设置为23/24
         } else {
-            mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_12_HOUR_VIEW);
+            mHourSpinner.setMinValue(HOUR_SPINNER_MIN_VAL_12_HOUR_VIEW); // 如果12，小时选择器的最小值 1
-            mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_12_HOUR_VIEW);
+            mHourSpinner.setMaxValue(HOUR_SPINNER_MAX_VAL_12_HOUR_VIEW); // 小时选择器的最大值 12
         }
     }
 
@@ -472,14 +533,17 @@ public class DateTimePicker extends FrameLayout {
      * Set the callback that indicates the 'Set' button has been pressed.
      * @param callback the callback, if null will do nothing
      */
+
+    //设置一个回调函数，当用户点击"设置"时出发
     public void setOnDateTimeChangedListener(OnDateTimeChangedListener callback) {
-        mOnDateTimeChangedListener = callback;
+        mOnDateTimeChangedListener = callback; //赋值回调接口
     }
 
+    //调用回调函数，当日期或者时间发生改变时，这个方法通知订阅了监听器的客户端
     private void onDateTimeChanged() {
         if (mOnDateTimeChangedListener != null) {
             mOnDateTimeChangedListener.onDateTimeChanged(this, getCurrentYear(),
-                    getCurrentMonth(), getCurrentDay(), getCurrentHourOfDay(), getCurrentMinute());
+                    getCurrentMonth(), getCurrentDay(), getCurrentHourOfDay(), getCurrentMinute()); //传递更新后的值给监听器
         }
     }
 }

src/net/micode/notes/ui/DateTimePickerDialog.java

@@ -29,61 +29,75 @@ import android.content.DialogInterface.OnClickListener;
 import android.text.format.DateFormat;
 import android.text.format.DateUtils;
 
+//继承自 AlertDialog，包含日期和时间选择的功能
 public class DateTimePickerDialog extends AlertDialog implements OnClickListener {
 
+    //用于存储当前选择日期和时间
     private Calendar mDate = Calendar.getInstance();
+    //标记是否使用24小时视图展示时间
     private boolean mIs24HourView;
+    //回调接口定义，当日期和时间设定后激活
     private OnDateTimeSetListener mOnDateTimeSetListener;
+    //本对话框包含的日期和时间选择器视图
     private DateTimePicker mDateTimePicker;
-
+    //定义回调接口，用于通知调用者日期和时间已经设定
     public interface OnDateTimeSetListener {
         void OnDateTimeSet(AlertDialog dialog, long date);
     }
 
+    //DateTimePickerDialog构造函数
     public DateTimePickerDialog(Context context, long date) {
-        super(context);
+        super(context); //调用AlertDiaglog构造函数
-        mDateTimePicker = new DateTimePicker(context);
+        mDateTimePicker = new DateTimePicker(context);//创建一个新的DateTimePicker实例
-        setView(mDateTimePicker);
+        setView(mDateTimePicker);//将DateTimePicker视图添加到对话框中
+        //注册一个回调，以在日期和时间改变时更新内部的Calendar实例
         mDateTimePicker.setOnDateTimeChangedListener(new OnDateTimeChangedListener() {
             public void onDateTimeChanged(DateTimePicker view, int year, int month,
                     int dayOfMonth, int hourOfDay, int minute) {
+                //更新Calendar实例的年、月、日、时、分
                 mDate.set(Calendar.YEAR, year);
                 mDate.set(Calendar.MONTH, month);
                 mDate.set(Calendar.DAY_OF_MONTH, dayOfMonth);
                 mDate.set(Calendar.HOUR_OF_DAY, hourOfDay);
                 mDate.set(Calendar.MINUTE, minute);
-                updateTitle(mDate.getTimeInMillis());
+                updateTitle(mDate.getTimeInMillis()); //更新对话框标题显示的日期
             }
         });
-        mDate.setTimeInMillis(date);
+        mDate.setTimeInMillis(date); // 将对话框初始化为传入的日期和时间值
-        mDate.set(Calendar.SECOND, 0);
+        mDate.set(Calendar.SECOND, 0); // 秒字段设为0
-        mDateTimePicker.setCurrentDate(mDate.getTimeInMillis());
+        mDateTimePicker.setCurrentDate(mDate.getTimeInMillis()); // 将DateTimePicker初始化到当前日期
+        //设置对话框的'确定'和'取消'按钮
         setButton(context.getString(R.string.datetime_dialog_ok), this);
         setButton2(context.getString(R.string.datetime_dialog_cancel), (OnClickListener)null);
+        //设置是否使用24小时视图
         set24HourView(DateFormat.is24HourFormat(this.getContext()));
-        updateTitle(mDate.getTimeInMillis());
+        updateTitle(mDate.getTimeInMillis()); // 初始对话框标题显示的日期和时间
     }
 
+    //设置时间是否显示为24小时视图
     public void set24HourView(boolean is24HourView) {
         mIs24HourView = is24HourView;
     }
 
+    //设置DateTimeSet监听回调
     public void setOnDateTimeSetListener(OnDateTimeSetListener callBack) {
         mOnDateTimeSetListener = callBack;
     }
 
+    //更新对话框标题显示的日期和时间
     private void updateTitle(long date) {
         int flag =
             DateUtils.FORMAT_SHOW_YEAR |
             DateUtils.FORMAT_SHOW_DATE |
             DateUtils.FORMAT_SHOW_TIME;
         flag |= mIs24HourView ? DateUtils.FORMAT_24HOUR : DateUtils.FORMAT_24HOUR;
-        setTitle(DateUtils.formatDateTime(this.getContext(), date, flag));
+        setTitle(DateUtils.formatDateTime(this.getContext(), date, flag)); // 格式化时间并设置标题
     }
 
+    //点击对话框按钮调用，通知监听者时间已设置
     public void onClick(DialogInterface arg0, int arg1) {
         if (mOnDateTimeSetListener != null) {
-            mOnDateTimeSetListener.OnDateTimeSet(this, mDate.getTimeInMillis());
+            mOnDateTimeSetListener.OnDateTimeSet(this, mDate.getTimeInMillis()); // 激活回调传递当前设置的日期和时间
         }
     }