自学鸿蒙应用开发（7）- Picker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"            />        <Picker            ohos: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>    <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.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 {    @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);        // 为按钮设置点击事件回调        button.setClickedListener(new Component.ClickedListener() {            public void onClick(Component v) {                new ToastDialog(getContext())                        .setText(tf.getText())                        .show();            }        });        //获取picker组件        Picker picker = (Picker) findComponentById(ResourceTable.Id_test_picker);        //设定表示文字        picker.setDisplayedData(new String[]{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"});        //设定事件响应        picker.setValueChangedListener((picker1, oldVal, newVal) -> {            tf.setText(picker1.getDisplayedData()[newVal - picker1.getMinValue()]);        });    }    @Override    public void onActive() {        super.onActive();    }    @Override    public void onForeground(Intent intent) {        super.onForeground(intent);    }}