本文介紹在鴻蒙應用中TabList和TabList.Tab組件的基本用法。
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准備TabList頁面布局
在layout目錄下創建TabList布局，將其命名為ability_tablist.xml。
<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayout
xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:height="match_parent"
ohos:width="match_parent"
ohos:orientation="vertical">
<TabList
ohos:id="$+id:tab_list"
ohos:background_element="#FFFF7F"
ohos:top_margin="10vp"
ohos:tab_margin="24vp"
ohos:tab_length="140vp"
ohos:text_size="20fp"
ohos:height="36vp"
ohos:width="match_parent"
ohos:layout_alignment="center"
ohos:orientation="horizontal"
ohos:text_alignment="center"
ohos:normal_text_color="#999999"
ohos:selected_text_color="#000000"
ohos:selected_tab_indicator_color="#000000"
ohos:selected_tab_indicator_height="2vp"/>
<DirectionalLayout
ohos:id="$+id:tab_container"
ohos:height="match_parent"
ohos:width="match_parent">
</DirectionalLayout>
</DirectionalLayout>
布局代碼中第7行~第22行的用於生成TabList組件，定義了TabList的基本屬性；第23行~第27行用於生成Tab頁面的容器，目前還沒有具體內容，稍后有具體代碼生成。
准備Image頁面
Image頁面主要包含一個Image文件和簡單的文字表示：
<?xml version="1.0" encoding="utf-8"?>
<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"
/>
<Component
ohos:height="20vp"
ohos:width="match_parent"
/>
<Text
ohos:id="$+id:text_helloworld"
ohos:height="match_content"
ohos:width="match_content"
ohos:layout_alignment="horizontal_center"
ohos:text="Image Tab"
ohos:text_color="#007F00"
ohos:text_size="100"
/>
</DirectionalLayout>
<Component
ohos:height="0vp"
ohos:weight="5"
ohos:width="match_parent"
/>
</DirectionalLayout>
准備Video頁面
Video頁面包含一個動畫，稍微復雜一些。首先是頁面本身：
<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayout
xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:height="match_parent"
ohos:width="match_parent"
ohos:orientation="vertical">
<Component
ohos:height="0vp"
ohos:weight="3"
ohos:width="match_parent"
/>
<DirectionalLayout
xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:height="match_content"
ohos:width="match_content"
ohos:layout_alignment="center"
ohos:orientation="vertical">
<Component
ohos:id="$+id:video_area"
ohos:height="300vp"
ohos:width="300vp"
/>
<Component
ohos:height="20vp"
ohos:width="match_parent"
/>
<Text
ohos:id="$+id:text_helloworld"
ohos:height="match_content"
ohos:width="match_content"
ohos:layout_alignment="horizontal_center"
ohos:text="Video Tab"
ohos:text_color="#0000FF"
ohos:text_size="100"
/>
</DirectionalLayout>
<Component
ohos:height="0vp"
ohos:weight="5"
ohos:width="match_parent"
/>
</DirectionalLayout>
這個文件和Image頁面區別不大，只是在用Component組件代替了Image組件。而動畫的實際內容則是由graphic目錄中的animation_element.xml文件決定：
<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:oneshot="false">
<item ohos:element="$media:video01" ohos:duration="100"/>
<item ohos:element="$media:video02" ohos:duration="100"/>
<item ohos:element="$media:video03" ohos:duration="100"/>
<item ohos:element="$media:video04" ohos:duration="100"/>
<item ohos:element="$media:video05" ohos:duration="100"/>
<item ohos:element="$media:video06" ohos:duration="100"/>
<item ohos:element="$media:video07" ohos:duration="100"/>
<item ohos:element="$media:video08" ohos:duration="100"/>
<item ohos:element="$media:video09" ohos:duration="100"/>
<item ohos:element="$media:video10" ohos:duration="100"/>
<item ohos:element="$media:video11" ohos:duration="100"/>
</animation-list>
生成TabList畫面
TabList的每個Tab頁面需要由代碼生成，具體參見下面的頁面類：
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.components.element.FrameAnimationElement;
import java.io.Console;
public class TablistAbilitySlice extends AbilitySlice {
private Component imageContent;
private Component videoContent;
private FrameAnimationElement frameAnimationElement;
@Override
public void onStart(Intent intent) {
super.onStart(intent);
super.setUIContent(ResourceTable.Layout_ability_tablist);
TabList tabList = (TabList) findComponentById(ResourceTable.Id_tab_list);
tabList.setTabLength(200); // 設置Tab的寬度
tabList.setTabMargin(26); // 設置兩個Tab之間的間距
TabList.Tab tab1 = tabList.new Tab(getContext());
tab1.setText("Image");
tabList.addTab(tab1);
TabList.Tab tab2 = tabList.new Tab(getContext());
tab2.setText("Video");
tabList.addTab(tab2);
AbilitySlice slice = this;
tabList.addTabSelectedListener(new TabList.TabSelectedListener() {
@Override
public void onSelected(TabList.Tab tab) {
ComponentContainer container = (ComponentContainer) findComponentById(ResourceTable.Id_tab_container);
if(tab.getText().equals("Image")) {
imageContent = LayoutScatter.getInstance(slice).parse(ResourceTable.Layout_iamge_tab, null, false);
container.addComponent(imageContent);
}
else
{
videoContent = LayoutScatter.getInstance(slice).parse(ResourceTable.Layout_video_tab, null, false);
frameAnimationElement = new FrameAnimationElement(slice.getContext(), ResourceTable.Graphic_animation_element);
Component videoArea = videoContent.findComponentById(ResourceTable.Id_video_area);
videoArea.setBackground(frameAnimationElement);
frameAnimationElement.start();
container.addComponent(videoContent);
}
}
@Override
public void onUnselected(TabList.Tab tab) {
if(tab.getText().equals("Video")) {
frameAnimationElement.start();
}
ComponentContainer container = (ComponentContainer) findComponentById(ResourceTable.Id_tab_container);
container.removeAllComponents();
}
@Override
public void onReselected(TabList.Tab tab) {
ComponentContainer container = (ComponentContainer) findComponentById(ResourceTable.Id_tab_container);
if(tab.getText().equals("Image")) {
container.addComponent(imageContent);
}
else
{
frameAnimationElement.start();
container.addComponent(videoContent);
}
}
});
//最開始選選擇tab1
tabList.selectTab(tab1);
}
@Override
public void onActive() {
super.onActive();
}
@Override
public void onForeground(Intent intent) {
super.onForeground(intent);
}
}
代碼第22行~第27行分別生成了Image和Video兩個Tab頁。
第29行~第69行是為TabList的各種事件提供響應。需要響應的處理主要有Tab頁選擇，Tab頁取消選擇和Tab重新選擇。代碼中根據當前選中的Tab頁面生成或選擇不同的組件。
參考文檔
TabList和Tab組件
https://developer.harmonyos.com/cn/docs/documentation/doc-guides/ui-java-component-tablist-tab-0000001062229749
TabList類
https://developer.harmonyos.com/cn/docs/documentation/doc-references/tablist-0000001054238721
Tab List.Tab類
https://developer.harmonyos.com/cn/docs/documentation/doc-references/tablist_tab-0000001054678691
動畫開發指導
https://developer.harmonyos.com/cn/docs/documentation/doc-guides/ui-java-animation-0000000000580278
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原文鏈接：https://developer.huawei.com/consumer/cn/forum/topic/0201551132050440304?fid=0101303901040230869
原作者：面向對象思考