自學(xué)鴻蒙應(yīng)用開發(fā)(12)- Checkbox
本文介紹在鴻蒙應(yīng)用中Checkbox組件的基本用法。
增加Checkbox組件
如下代碼中47行~52行所示,在布局中增加Checkbox組件。
<DirectionalLayoutxmlns:ohos="http://schemas.huawei.com/res/ohos"ohos:height="match_parent"ohos:width="match_parent"ohos:orientation="vertical"><Componentohos:height="0vp"ohos:weight="3"ohos:width="match_parent"/><DirectionalLayoutxmlns:ohos="http://schemas.huawei.com/res/ohos"ohos:height="match_content"ohos:width="match_content"ohos:layout_alignment="center"ohos:orientation="vertical"><Imageohos:id="$+id:image"ohos:width="match_content"ohos:height="match_content"ohos:layout_alignment="center"ohos:image_src="$media:DevEco"/><TextFieldohos: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"/><Buttonohos: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"/><Checkboxohos:id="$+id:check_box"ohos:height="match_content"ohos:width="match_content"ohos:layout_alignment="center"ohos:text="24小時(shí)制"ohos:text_size="20fp" /><TimePickerohos:id="$+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><Componentohos:height="0vp"ohos:weight="5"ohos:width="match_parent"/>DirectionalLayout>
代碼中組件id被指定為check_box,會(huì)在下面的響應(yīng)代碼中用到。
在代碼中使用Checkbox組件
下面代碼中的第20行獲取RadioContainer組件后,在第24行根據(jù)Checkbox的狀態(tài)更新TimePicker的形式,然后在第42行~45行為Checkbox增加響應(yīng)處理,其內(nèi)容是同樣是根據(jù)Checkbox的狀態(tài)更新TimePicker的形式。
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 {public void onStart(Intent intent) {super.onStart(intent);super.setUIContent(ResourceTable.Layout_ability_component);//獲取textfield輸入組件TextField tf = (TextField) findComponentById(ResourceTable.Id_text_field);//獲取button組件Button button = (Button) findComponentById(ResourceTable.Id_hello_button);????????//獲取Checkbox組件Checkbox check_box = (Checkbox)findComponentById(ResourceTable.Id_check_box);//獲取TimePicker組件TimePicker picker = (TimePicker) findComponentById(ResourceTable.Id_time_picker);????????//根據(jù)Checkbox的狀態(tài)設(shè)定TimePicker的形式。picker.set24Hour(check_box.isChecked());// 為按鈕設(shè)置點(diǎn)擊事件回調(diào)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 = "所選時(shí)間比現(xiàn)在時(shí)刻早" + pickTime.until(rightNow, ChronoUnit.SECONDS) + "秒";else if(pickTime.isAfter(rightNow))msg = "所選時(shí)間比現(xiàn)在時(shí)刻晚" + rightNow.until(pickTime, ChronoUnit.SECONDS) + "秒";elsemsg = "所選時(shí)間和現(xiàn)在時(shí)刻一樣";new ToastDialog(getContext()).setText(msg).show();}});//為RadioContainer設(shè)置事件響應(yīng)check_box.setCheckedStateChangedListener((view, state) -> {picker.set24Hour(state);});//為TimePicker設(shè)定事件響應(yīng)picker.setTimeChangedListener(new TimePicker.TimeChangedListener() {public void onTimeChanged(TimePicker timePicker, int hour, int minute, int second) {tf.setText(hour + ":" + minute + ":" + second);}});}public void onActive() {super.onActive();}public void onForeground(Intent intent) {super.onForeground(intent);}}
畫面顯示如下:
參考文檔
Checkbox組件
https://developer.harmonyos.com/cn/docs/documentation/doc-guides/ui-java-component-checkbox-0000001060487804
Checkbox類
https://developer.harmonyos.com/cn/docs/documentation/doc-references/checkbox-0000001054558715
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