自学鸿蒙应用开发(9)- TimePicker组件
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·
2021-01-04 17:46
本文介绍在鸿蒙应用中TimePicker组件的基本用法。
增加TimePicker组件
如下代码中46行~52行所示,在布局中增加TimePicker组件。
<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>
代码中组件id被指定为time_picker会在下面的响应代码中用到。
在代码中使用TimePicker组件
如下面代码中21行~49行所示,在获取TimePicker组件后,一方面在button的动作响应中计算所选时刻和当前时刻的秒数差之后用小窗口表示出来;另一方面在用户操作TimePicker时将选择结果表示在TextFile组件上。
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 {
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datepicker组件
TimePicker picker = (TimePicker) findComponentById(ResourceTable.Id_time_picker);
// 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();
}
});
//设定事件响应
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);
}
画面显示如下:
参考文档
Picker组件:
https://developer.harmonyos.com/cn/docs/documentation/doc-guides/ui-java-component-timepicker-0000001060648140
TimePicker类:
https://developer.harmonyos.com/cn/docs/documentation/doc-references/timepicker-0000001054119980
LocalTime类
https://developer.harmonyos.com/cn/docs/documentation/doc-references/localtime-0000001054119826
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