自学鸿蒙应用开发（12）- Checkbox

<DirectionalLayout    xmlns:ohos="http://schemas.huawei.com/res/ohos"    ohos:height="match_parent"    ohos:width="match_parent"    ohos:orientation="vertical">    <Component        ohos:height="0vp"        ohos:weight="3"        ohos:width="match_parent"        />    <DirectionalLayout        xmlns:ohos="http://schemas.huawei.com/res/ohos"        ohos:height="match_content"        ohos:width="match_content"        ohos:layout_alignment="center"        ohos:orientation="vertical">        <Image            ohos:id="$+id:image"            ohos:width="match_content"            ohos:height="match_content"            ohos:layout_alignment="center"            ohos:image_src="$media:DevEco"        />        <TextField            ohos:id="$+id:text_field"            ohos:width="match_parent"            ohos:height="30vp"            ohos:text_size="20fp"            ohos:text_alignment="center"            ohos:hint="Please input text and press [Click me!] button."            ohos:background_element="$graphic:background_text_field"        />        <Button            ohos:id="$+id:hello_button"            ohos:width="match_content"            ohos:height="match_content"            ohos:text_size="27fp"            ohos:text="Click me!"            ohos:layout_alignment="center"            ohos:background_element="$graphic:background_button"            ohos:margin="15vp"            ohos:right_padding="8vp"            ohos:left_padding="8vp"            />        <Checkbox            ohos:id="$+id:check_box"            ohos:height="match_content"            ohos:width="match_content"            ohos:layout_alignment="center"            ohos:text="24小时制"            ohos:text_size="20fp" />        <TimePicker            ohos:id="$+id:time_picker"            ohos:24_hour_mode="false"            ohos:height="match_content"            ohos:width="match_parent"            ohos:layout_alignment="horizontal_center"            ohos:text_am="AM"            ohos:text_pm="PM"            ohos:normal_text_size="20fp"            ohos:selected_text_size="25fp"/>    DirectionalLayout>    <Component        ohos:height="0vp"        ohos:weight="5"        ohos:width="match_parent"        />DirectionalLayout>

package com.example.helloharmony.slice;import com.example.helloharmony.ResourceTable;import ohos.aafwk.ability.AbilitySlice;import ohos.aafwk.content.Intent;import ohos.agp.components.*;import ohos.agp.window.dialog.ToastDialog;import java.time.LocalTime;import java.time.temporal.ChronoUnit;
public class ComponentAbilitySlice extends AbilitySlice {    @Override    public void onStart(Intent intent) {        super.onStart(intent);        super.setUIContent(ResourceTable.Layout_ability_component);        //获取textfield输入组件        TextField tf = (TextField) findComponentById(ResourceTable.Id_text_field);        //获取button组件        Button button = (Button) findComponentById(ResourceTable.Id_hello_button);        //获取Checkbox组件        Checkbox check_box = (Checkbox)findComponentById(ResourceTable.Id_check_box);        //获取TimePicker组件        TimePicker picker = (TimePicker) findComponentById(ResourceTable.Id_time_picker);        //根据Checkbox的状态设定TimePicker的形式。        picker.set24Hour(check_box.isChecked());        // 为按钮设置点击事件回调        button.setClickedListener(new Component.ClickedListener() {            public void onClick(Component v) {                LocalTime rightNow = LocalTime.now();                LocalTime pickTime = LocalTime.of(picker.getHour(), picker.getMinute(), picker.getSecond());                String msg;                if(pickTime.isBefore(rightNow))                    msg = "所选时间比现在时刻早" + pickTime.until(rightNow, ChronoUnit.SECONDS) + "秒";                else if(pickTime.isAfter(rightNow))                    msg = "所选时间比现在时刻晚" + rightNow.until(pickTime, ChronoUnit.SECONDS) + "秒";                else                    msg = "所选时间和现在时刻一样";                new ToastDialog(getContext())                        .setText(msg)                        .show();            }        });        //为RadioContainer设置事件响应        check_box.setCheckedStateChangedListener((view, state) -> {            picker.set24Hour(state);        });        //为TimePicker设定事件响应        picker.setTimeChangedListener(            new TimePicker.TimeChangedListener() {                @Override                public void onTimeChanged(TimePicker timePicker, int hour, int minute, int second) {                    tf.setText(hour + ":" + minute + ":" + second);                }            }        );    }    @Override    public void onActive() {        super.onActive();    }    @Override    public void onForeground(Intent intent) {        super.onForeground(intent);    }}