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          自學(xué)鴻蒙應(yīng)用開發(fā)(9)- TimePicker組件

          本文介紹在鴻蒙應(yīng)用中TimePicker組件的基本用法。

          增加TimePicker組件

          如下代碼中46行~52行所示,在布局中增加TimePicker組件。

          <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"            />        <TimePicker            ohos:id="$+id:time_picker"            ohos:24_hour_mode="false"            ohos:height="match_content"            ohos:width="match_parent"            ohos:normal_text_size="20fp"            ohos:selected_text_size="40fp"/>    DirectionalLayout>    <Component        ohos:height="0vp"        ohos:weight="5"        ohos:width="match_parent"        />DirectionalLayout>

          代碼中組件id被指定為time_picker會在下面的響應(yīng)代碼中用到。


          在代碼中使用TimePicker組件

          如下面代碼中21行~49行所示,在獲取TimePicker組件后,一方面在button的動作響應(yīng)中計(jì)算所選時(shí)刻和當(dāng)前時(shí)刻的秒數(shù)差之后用小窗口表示出來;另一方面在用戶操作TimePicker時(shí)將選擇結(jié)果表示在TextFile組件上。

          import ohos.aafwk.ability.AbilitySlice;import ohos.aafwk.content.Intent;import ohos.agp.components.Button;import ohos.agp.components.Component;import ohos.agp.components.TimePicker;import ohos.agp.components.TextField;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); //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datepicker組件 TimePicker picker = (TimePicker) findComponentById(ResourceTable.Id_time_picker); // 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"; else msg = "所選時(shí)間和現(xiàn)在時(shí)刻一樣";
          new ToastDialog(getContext()) .setText(msg) .show(); } }); //設(shè)定事件響應(yīng) 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); }


          畫面顯示如下:


          參考文檔

          Picker組件:

          https://developer.harmonyos.com/cn/docs/documentation/doc-guides/ui-java-component-timepicker-0000001060648140

          TimePicker類:

          https://developer.harmonyos.com/cn/docs/documentation/doc-references/timepicker-0000001054119980

          LocalTime類

          https://developer.harmonyos.com/cn/docs/documentation/doc-references/localtime-0000001054119826

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          《實(shí)戰(zhàn)Python設(shè)計(jì)模式》是作者最近出版的新書,拜托多多關(guān)注!

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