HarmonyOS实战—服务卡片初体验
美男子玩编程
共 54595字，需浏览 110分钟
·
2021-07-07 12:18
最近看到很多博客网站上出现了HarmonyOS的征文活动，看到那些精美的奖品让我也安耐不住开了，当然奖品的诱惑当然是抵挡不住我对技术的狂热追求，对于开发者而言技术没有顶峰没有终点。
那么今天给大家做一个卡片服务开发的经验分享，如果有什么地方说的不对的请各位开发者进行指正，如果有什么问题也可以发私信或者直接在帖子中留言，我也会及时回复大家。
1
什么是服务卡片
服务卡片（以下简称“卡片”）是FA的一种界面展示形式，将FA的重要信息或操作直接放置到卡片中，用户通过直接操作卡片就可以达到应用的使用体验，这样做大大减少了应用的使用层级性。
卡片常用于嵌入到其他应用中作为其界面的一部分显示（也可以使用原子化服务将应用保存到服务中心中，这种方式不需要安装应用），并支持拉起页面，发送消息等基础的交互功能。
原子化服务在下个帖子中介绍。
示例如下图所示：
为了开发者能够便于理解，官方将服务卡片分为三方面：
卡片使用方显示卡片内容的宿主应用，控制卡片在宿主中展示的位置。 卡片管理服务用于管理系统中所添加卡片的常驻代理服务，包括卡片对象的管理与使用，以及卡片周期性刷新等。 卡片提供方提供卡片显示内容的HarmonyOS应用或原子化服务，控制卡片的显示内容、控件布局以及控件点击事件
卡片使用方和提供方不要求常驻运行，在需要添加/删除/请求更新卡片时，卡片管理服务会拉起卡片提供方获取卡片信息。
2
服务卡片的运作机制
文字描述滞后，先上图。（图片由官网提供，此处借用一下）
从图中可以清楚的看到卡片服务的整体通信层都是由"RPC"负责，通过通信适配层构成了数据发送接收的通道。
卡片管理服务
周期性刷新：在卡片添加后，根据卡片的刷新策略启动定时任务周期性触发卡片的刷新。 卡片缓存管理：在卡片添加到卡片管理服务后，对卡片的视图信息进行缓存，以便下次获取卡片时可以直接返回缓存数据，降低时延。 卡片生命周期管理：对于卡片切换到后台或者被遮挡时，暂停卡片的刷新；以及卡片的升级/卸载场景下对卡片数据的更新和清理。 卡片使用方对象管理：对卡片使用方的RPC对象进行管理，用于使用方请求进行校验以及对卡片更新后的回调处理。
卡片提供方
创建卡片实例并实现onCreateForm、onUpdateForm和onDeleteForm处理创建卡片、更新卡片以及删除卡片等请求，提供相应的卡片服务。
3
服务卡片的实现（java）
第一步、下载、安装、配置 DevEco Studio
第二步、运行DevEco Studio创建新项目
因为要使用java语言编写，所以此处要选择支持Java语言的空页面。
选择成功进入新建项目配置界面。
点击Finish进入项目。
第三步、添加卡片模板
创建模板：右击“Entry”→“New”→“Server Widget”，如下所示：
设置模板，如下所示：
第四步、查看卡片服务配置
项目目录，如下所示：
由图可见：添加卡片模板后在原来项目中增加一个widget文件夹，并在文件夹中出现了三个文件FormControllerManager.java、FormController.java、CardWidgetImpl.java。
三个文件对应了卡片服务的运行机制，通过关系的对应可以清楚的了解到代码运行原理。
FormControllerManager.java（卡片控制器管理【卡片服务管理】）。
public class FormControllerManager {
private static final HiLogLabel TAG = new HiLogLabel(HiLog.DEBUG, 0x0, FormControllerManager.class.getName());
private static final String PACKAGE_PATH = "com.example.carddemo.widget";
private static final String SHARED_SP_NAME = "form_info_sp.xml";
private static final String FORM_NAME = "formName";
private static final String DIMENSION = "dimension";
private static FormControllerManager managerInstance = null;
private final HashMap<Long, FormController> controllerHashMap = new HashMap<>();
private final Context context;
private final Preferences preferences;
/**
* 初始化构造器
*
* @param context instance of Context.
*/
private FormControllerManager(Context context) {
this.context = context;
DatabaseHelper databaseHelper = new DatabaseHelper(this.context.getApplicationContext());
preferences = databaseHelper.getPreferences(SHARED_SP_NAME);
}
/**
* FormControllerManager 实例化
*
* @param context instance of Context.
* @return FormControllerManager instance.
*/
public static FormControllerManager getInstance(Context context) {
if (managerInstance == null) {
synchronized (FormControllerManager.class) {
if (managerInstance == null) {
managerInstance = new FormControllerManager(context);
}
}
}
return managerInstance;
}
/**
* 通过构造器将传入的卡片信息进行封装，返回卡片服务
*
* @param formId form id.
* @param formName form name.
* @param dimension form dimension
* @return FormController form controller
*/
public FormController createFormController(long formId, String formName, int dimension) {
synchronized (controllerHashMap) {
if (formId < 0 || formName.isEmpty()) {
return null;
}
HiLog.info(TAG,
"saveFormId() formId: " + formId + ", formName: " + formName + ", preferences: " + preferences);
if (preferences != null) {
ZSONObject formObj = new ZSONObject();
formObj.put(FORM_NAME, formName);
formObj.put(DIMENSION, dimension);
preferences.putString(Long.toString(formId), ZSONObject.toZSONString(formObj));
preferences.flushSync();
}
// Create controller instance.
FormController controller = newInstance(formName, dimension, context);
// Cache the controller.
if (controller != null) {
if (!controllerHashMap.containsKey(formId)) {
controllerHashMap.put(formId, controller);
}
}
return controller;
}
}
/**
* 获取卡片控制器实例
*
* @param formId form id.
* @return the instance of form controller.
*/
public FormController getController(long formId) {
synchronized (controllerHashMap) {
if (controllerHashMap.containsKey(formId)) {
return controllerHashMap.get(formId);
}
Map<String, ?> forms = preferences.getAll();
String formIdString = Long.toString(formId);
if (forms.containsKey(formIdString)) {
ZSONObject formObj = ZSONObject.stringToZSON((String) forms.get(formIdString));
String formName = formObj.getString(FORM_NAME);
int dimension = formObj.getIntValue(DIMENSION);
FormController controller = newInstance(formName, dimension, context);
controllerHashMap.put(formId, controller);
}
return controllerHashMap.get(formId);
}
}
private FormController newInstance(String formName, int dimension, Context context) {
FormController ctrInstance = null;
if (formName == null || formName.isEmpty()) {
HiLog.error(TAG, "newInstance() get empty form name");
return ctrInstance;
}
try {
String className = PACKAGE_PATH + "." + formName.toLowerCase(Locale.ROOT) + "."
+ getClassNameByFormName(formName);
Class<?> clazz = Class.forName(className);
if (clazz != null) {
Object controllerInstance = clazz.getConstructor(Context.class, String.class, Integer.class)
.newInstance(context, formName, dimension);
if (controllerInstance instanceof FormController) {
ctrInstance = (FormController) controllerInstance;
}
}
} catch (NoSuchMethodException | InstantiationException | IllegalArgumentException | InvocationTargetException
| IllegalAccessException | ClassNotFoundException | SecurityException exception) {
HiLog.error(TAG, "newInstance() get exception: " + exception.getMessage());
}
return ctrInstance;
}
/**
* 从数组中获取所有卡片id
*
* @return form id list
*/
public List<Long> getAllFormIdFromSharePreference() {
List<Long> result = new ArrayList<>();
Map<String, ?> forms = preferences.getAll();
for (String formId : forms.keySet()) {
result.add(Long.parseLong(formId));
}
return result;
}
/**
* 删除卡片服务
*
* @param formId form id
*/
public void deleteFormController(long formId) {
synchronized (controllerHashMap) {
preferences.delete(Long.toString(formId));
preferences.flushSync();
controllerHashMap.remove(formId);
}
}
private String getClassNameByFormName(String formName) {
String[] strings = formName.split("_");
StringBuilder result = new StringBuilder();
for (String string : strings) {
result.append(string);
}
char[] charResult = result.toString().toCharArray();
charResult[0] = (charResult[0] >= 'a' && charResult[0] <= 'z') ? (char) (charResult[0] - 32) : charResult[0];
return String.copyValueOf(charResult) + "Impl";
}
}
FormController.java（卡片控制器【卡片提供方】）。
public abstract class FormController {
protected final Context context;
protected final String formName;
protected final int dimension;
public FormController(Context context, String formName, Integer dimension) {
this.context = context;
this.formName = formName;
this.dimension = dimension;
}
/**
* 创建卡片信息提供者
*/
public abstract ProviderFormInfo bindFormData();
/**
* 更新卡片信息
*/
public abstract void updateFormData(long formId, Object... vars);
/**
* 在接收服务小部件消息事件时调用
*/
public abstract void onTriggerFormEvent(long formId, String message);
/**
* 获取路由的目标界面
*/
public abstract Class<? extends AbilitySlice> getRoutePageSlice(Intent intent);
}
CardWidgetImpl.java（卡片应用【卡片使用方】）。
public class CardWidgetImpl extends FormController {
public static final int DIMENSION_1X2 = 1;
public static final int DIMENSION_2X4 = 3;
private static final HiLogLabel TAG = new HiLogLabel(HiLog.DEBUG, 0x0, CardWidgetImpl.class.getName());
private static final int DEFAULT_DIMENSION_2X2 = 2;
private static final Map<Integer, Integer> RESOURCE_ID_MAP = new HashMap<>();
static {
RESOURCE_ID_MAP.put(DIMENSION_1X2, ResourceTable.Layout_form_grid_pattern_cardwidget_1_2);
RESOURCE_ID_MAP.put(DEFAULT_DIMENSION_2X2, ResourceTable.Layout_form_grid_pattern_cardwidget_2_2);
RESOURCE_ID_MAP.put(DIMENSION_2X4, ResourceTable.Layout_form_grid_pattern_cardwidget_2_4);
}
public CardWidgetImpl(Context context, String formName, Integer dimension) {
super(context, formName, dimension);
}
//创建好卡片服务后，在界面展示卡片
@Override
public ProviderFormInfo bindFormData() {
HiLog.info(TAG, "bind form data when create form");
return new ProviderFormInfo(RESOURCE_ID_MAP.get(dimension), context);
}
//更新卡片信息
@Override
public void updateFormData(long formId, Object... vars) {
HiLog.info(TAG, "update form data timing, default 30 minutes");
}
//卡片中内容手势触发方法
@Override
public void onTriggerFormEvent(long formId, String message) {
HiLog.info(TAG, "handle card click event.");
}
@Override
public Class<? extends AbilitySlice> getRoutePageSlice(Intent intent) {
HiLog.info(TAG, "get the default page to route when you click card.");
return null;
}
}
MainAbility的变化，新增了一些方法。
public class MainAbility extends Ability {
public static final int DEFAULT_DIMENSION_2X2 = 2;
public static final int DIMENSION_1X2 = 1;
public static final int DIMENSION_2X4 = 3;
public static final int DIMENSION_4X4 = 4;
private static final int INVALID_FORM_ID = -1;
private static final HiLogLabel TAG = new HiLogLabel(HiLog.DEBUG, 0x0, MainAbility.class.getName());
private String topWidgetSlice;
@Override
public void onStart(Intent intent) {
super.onStart(intent);
super.setMainRoute(MainAbilitySlice.class.getName());
if (intentFromWidget(intent)) {
topWidgetSlice = getRoutePageSlice(intent);
if (topWidgetSlice != null) {
setMainRoute(topWidgetSlice);
}
}
stopAbility(intent);
}
//创建卡片信息并返回卡片内容
@Override
protected ProviderFormInfo onCreateForm(Intent intent) {
HiLog.info(TAG, "onCreateForm");
long formId = intent.getLongParam(AbilitySlice.PARAM_FORM_IDENTITY_KEY, INVALID_FORM_ID);
String formName = intent.getStringParam(AbilitySlice.PARAM_FORM_NAME_KEY);
int dimension = intent.getIntParam(AbilitySlice.PARAM_FORM_DIMENSION_KEY, DEFAULT_DIMENSION_2X2);
HiLog.info(TAG, "onCreateForm: formId=" + formId + ",formName=" + formName);
FormControllerManager formControllerManager = FormControllerManager.getInstance(this);
FormController formController = formControllerManager.getController(formId);
//通过调用布局Id将卡片布局与卡片信息进行绑定
formController = (formController == null) ? formControllerManager.createFormController(formId,
formName, dimension) : formController;
if (formController == null) {
HiLog.error(TAG, "Get null controller. formId: " + formId + ", formName: " + formName);
return null;
}
return formController.bindFormData();
}
//更新卡片信息
@Override
protected void onUpdateForm(long formId) {
HiLog.info(TAG, "onUpdateForm");
super.onUpdateForm(formId);
FormControllerManager formControllerManager = FormControllerManager.getInstance(this);
FormController formController = formControllerManager.getController(formId);
formController.updateFormData(formId);
}
//删除卡片
@Override
protected void onDeleteForm(long formId) {
HiLog.info(TAG, "onDeleteForm: formId=" + formId);
super.onDeleteForm(formId);
FormControllerManager formControllerManager = FormControllerManager.getInstance(this);
formControllerManager.deleteFormController(formId);
}
//卡片手势触发
@Override
protected void onTriggerFormEvent(long formId, String message) {
HiLog.info(TAG, "onTriggerFormEvent: " + message);
super.onTriggerFormEvent(formId, message);
FormControllerManager formControllerManager = FormControllerManager.getInstance(this);
FormController formController = formControllerManager.getController(formId);
formController.onTriggerFormEvent(formId, message);
}
@Override
public void onNewIntent(Intent intent) {
if (intentFromWidget(intent)) { // Only response to it when starting from a service widget.
String newWidgetSlice = getRoutePageSlice(intent);
if (topWidgetSlice == null || !topWidgetSlice.equals(newWidgetSlice)) {
topWidgetSlice = newWidgetSlice;
restart();
}
}
}
private boolean intentFromWidget(Intent intent) {
long formId = intent.getLongParam(AbilitySlice.PARAM_FORM_IDENTITY_KEY, INVALID_FORM_ID);
return formId != INVALID_FORM_ID;
}
//跳转至对应的卡片界面
private String getRoutePageSlice(Intent intent) {
long formId = intent.getLongParam(AbilitySlice.PARAM_FORM_IDENTITY_KEY, INVALID_FORM_ID);
if (formId == INVALID_FORM_ID) {
return null;
}
FormControllerManager formControllerManager = FormControllerManager.getInstance(this);
FormController formController = formControllerManager.getController(formId);
if (formController == null) {
return null;
}
Class<? extends AbilitySlice> clazz = formController.getRoutePageSlice(intent);
if (clazz == null) {
return null;
}
return clazz.getName();
}
}
配置文件，如下所示：
第五步、编写卡片界面
分别修改form_grid_pattern_cardwidget_1_2、form_grid_pattern_cardwidget_2_2.xml和form_grid_pattern_cardwidget_2_4.xml文件。
form_grid_pattern_cardwidget_1_2.xml
<?xml version="1.0" encoding="utf-8"?><DependentLayout
xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:height="match_parent"
ohos:width="match_parent"
ohos:remote="true">
<Image
ohos:height="match_parent"
ohos:width="match_parent"
ohos:background_element="#1281f0"
ohos:scale\_mode="clip\_center"/>
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:alignment="center"
ohos:orientation="horizontal">
<Text
ohos:id="$+id:tv_name"
ohos:height="match_content"
ohos:width="match_content"
ohos:text="$string:cardwidget_title"
ohos:text_color="#E5FFFFFF"
ohos:text_size="16fp"
ohos:text_weight="1200"/>
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="3350"
ohos:text_color="#E5FFFFFF"
ohos:text_size="16fp"
ohos:text_weight="1200"/>
</DirectionalLayout></DependentLayout>
form_grid_pattern_cardwidget_2_2.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:background_element="#FFFFFFFF"
ohos:remote="true"
ohos:orientation="vertical">
<DirectionalLayout
ohos:id="$+id:tv_top"
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1"
ohos:orientation="horizontal">
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1"
ohos:orientation="vertical"
ohos:alignment="center">
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="消耗热量"
ohos:top_margin="5vp"
ohos:text_size="10fp"
ohos:text_weight="500">
</Text>
<Text
ohos:height="60vp"
ohos:width="60vp"
ohos:text="2.1 Kcal"
ohos:text_alignment="center"
ohos:text_color="#1281f0"
ohos:background\_element="$media:aa\_1"
ohos:text_size="10fp"
ohos:text_weight="500"/>
</DirectionalLayout>
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1"
ohos:orientation="vertical"
ohos:alignment="center">
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="实时心率"
ohos:top_margin="5vp"
ohos:text_size="10fp"
ohos:text_weight="500">
</Text>
<Text
ohos:height="60vp"
ohos:width="60vp"
ohos:text="99/min"
ohos:text_alignment="center"
ohos:text_color="#1281f0"
ohos:background\_element="$media:aa\_1"
ohos:text_size="10fp"
ohos:text_weight="500"/>
</DirectionalLayout>
</DirectionalLayout>
<DirectionalLayout
ohos:id="$+id:tv_blow"
ohos:height="60vp"
ohos:width="match_parent"
ohos:align\_parent\_bottom="true"
ohos:background_element="#1281f0"
ohos:alignment="center"
ohos:orientation="vertical">
<DirectionalLayout
ohos:height="match_content"
ohos:width="match_parent"
ohos:alignment="center"
ohos:orientation="horizontal">
<Text
ohos:id="$+id:tv_name"
ohos:height="match_content"
ohos:width="match_content"
ohos:text="$string:cardwidget_title"
ohos:text_color="#E5FFFFFF"
ohos:text_size="16fp"
ohos:text_weight="600"/>
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="3350"
ohos:text_color="#E5FFFFFF"
ohos:text_size="16fp"
ohos:text_weight="1000"/>
</DirectionalLayout>
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="$string:cardwidget_introduction"
ohos:text_color="#ffffff"
ohos:text_size="14fp"
ohos:text_weight="800"
ohos:top_margin="7vp"/>
</DirectionalLayout></DirectionalLayout>
form_grid_pattern_cardwidget_2_4.xml
<?xml version="1.0" encoding="utf-8"?><DirectionalLayout
xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:height="match_parent"
ohos:width="match_parent"
ohos:background_element="#FFFFFFFF"
ohos:orientation="horizontal"
ohos:remote="true">
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1"
ohos:orientation="vertical">
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1"
ohos:orientation="horizontal">
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1"
ohos:orientation="vertical"
ohos:alignment="center">
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="消耗热量"
ohos:top_margin="5vp"
ohos:text_size="10fp"
ohos:text_weight="500">
</Text>
<Text
ohos:height="60vp"
ohos:width="60vp"
ohos:text="2.1 Kcal"
ohos:text_alignment="center"
ohos:text_color="#1281f0"
ohos:background\_element="$media:aa\_1"
ohos:text_size="10fp"
ohos:text_weight="500"/>
</DirectionalLayout>
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1"
ohos:orientation="vertical"
ohos:alignment="center">
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="实时心率"
ohos:top_margin="5vp"
ohos:text_size="10fp"
ohos:text_weight="500">
</Text>
<Text
ohos:height="60vp"
ohos:width="60vp"
ohos:text="99/min"
ohos:text_alignment="center"
ohos:text_color="#1281f0"
ohos:background\_element="$media:aa\_1"
ohos:text_size="10fp"
ohos:text_weight="500"/>
</DirectionalLayout>
</DirectionalLayout>
<DirectionalLayout
ohos:height="60vp"
ohos:width="match_parent"
ohos:align\_parent\_bottom="true"
ohos:background_element="#1281f0"
ohos:alignment="center"
ohos:orientation="vertical">
<DirectionalLayout
ohos:height="match_content"
ohos:width="match_parent"
ohos:alignment="center"
ohos:orientation="horizontal">
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="$string:cardwidget_title"
ohos:text_color="#E5FFFFFF"
ohos:text_size="16fp"
ohos:text_weight="600"/>
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="3350"
ohos:text_color="#E5FFFFFF"
ohos:text_size="16fp"
ohos:text_weight="1000"/>
</DirectionalLayout>
<Text
ohos:height="match_content"
ohos:width="match_content"
ohos:text="$string:cardwidget_introduction"
ohos:text_color="#ffffff"
ohos:text_size="14fp"
ohos:text_weight="800"
ohos:top_margin="7vp"/>
</DirectionalLayout>
</DirectionalLayout>
<DirectionalLayout
ohos:height="match_parent"
ohos:width="match_parent"
ohos:weight="1">
</DirectionalLayout></DirectionalLayout>第六步、运行程序、查看效果
点击图标上划，出现卡片，如下所示：
点击右上角图钉按钮，将卡片放在屏幕中，如下所示：
长按应用，出现服务卡片，如下所示：
点击服务卡片选择界面，上下滑动可选择卡片内容，如下所示：
点击添加到桌面，则将卡片添加到桌面中，如下所示：
至此，卡片服务应用就以全部开发完成，后续会对卡片内部进行相关编写。使其进行动态的刷新及动态的获取数据。
往期推荐
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