自學(xué)鴻蒙應(yīng)用開發(fā)(7)- Picker組件
本文介紹在鴻蒙應(yīng)用中Picker組件的基本用法。
增加Picker組件
如下代碼中46行~56行所示,在布局中增加Picker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"/><Pickerohos:id="$+id:test_picker"ohos:height="match_content"ohos:width="300vp"ohos:min_value="0"ohos:max_value="6"ohos:wheel_mode_enabled="true"ohos:background_element="#E1FFFF"ohos:layout_alignment="horizontal_center"ohos:normal_text_size="16fp"ohos:selected_text_size="32fp"/>DirectionalLayout><Componentohos:height="0vp"ohos:weight="5"ohos:width="match_parent"/>DirectionalLayout>
代碼中組件id被指定為test_picker,會(huì)在下面的響應(yīng)代碼中用到。
獲取Picker組件設(shè)定和取得表示信息
如下面代碼中30行和36行所示,在獲取PIcker組件后,設(shè)定表示信息并在動(dòng)作響應(yīng)代碼將最新表示信息設(shè)定到TextField組件上。
package com.example.helloharmony.slice;import com.example.helloharmony.ResourceTable;import ohos.aafwk.ability.AbilitySlice;import ohos.aafwk.content.Intent;import ohos.agp.components.Button;import ohos.agp.components.Component;import ohos.agp.components.Picker;import ohos.agp.components.TextField;import ohos.agp.utils.LayoutAlignment;import ohos.agp.window.dialog.ToastDialog;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);// 為按鈕設(shè)置點(diǎn)擊事件回調(diào)button.setClickedListener(new Component.ClickedListener() {public void onClick(Component v) {new ToastDialog(getContext()).setText(tf.getText()).show();}});//獲取picker組件Picker picker = (Picker) findComponentById(ResourceTable.Id_test_picker);//設(shè)定表示文字picker.setDisplayedData(new String[]{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"});//設(shè)定事件響應(yīng)picker.setValueChangedListener((picker1, oldVal, newVal) -> {tf.setText(picker1.getDisplayedData()[newVal - picker1.getMinValue()]);});}public void onActive() {super.onActive();}public void onForeground(Intent intent) {super.onForeground(intent);}}
畫面顯示如下:
參考文檔
Picker類:
https://developer.harmonyos.com/cn/docs/documentation/doc-references/picker-0000001054119976
Picker組件:
https://developer.harmonyos.com/cn/docs/documentation/doc-guides/ui-java-component-picker-0000001059807909
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