目录：java

源码里是有Feature的示例的，但当本身写一个本身的Feature时，却遇到了各类问题，有些是示例代码和文档没有说明的小坑，这里记录一下。因源码里的startup目录没有任何代码，就选择它来存放代码。开发

1.  BUILD.gn文件里的source_set("startup")须要修改为 static_library("startup")。文档

source_set 应该是不会打包进去仍是什么，代码不会被执行，修改为static_library发现bin文件也增大了一些。字符串

2.  使用SYSEX_FEATURE_INIT(Init);进行初始化便可，可不使用SYS_RUN()和CORE_INI()宏。get

3.  直接使用SAMGR_GetInstance()->RegisterFeature()，并不能启动Feature。Feature的启动须要配全Service一块使用，在使用SAMGR_GetInstance()->RegisterFeature()前须要先SAMGR_GetInstance()->RegisterService()注册一个同命的Service才行。这点是最坑的地址，注册Feature时参数是Service名称字符串，因此就很容易想到直接注册就能够了，结束事实证实这样是行不通的。源码

4.  头文件的顺序，#include 要在#include "hctest.h"以前，不然SYSEX_FEATURE_INIT引用的是hos_init.h里的声明，而不是ohos_init.h文件里的声明

下面看一下添加Feature的正确方式：

1.  建立Service变量

static const char *GetName(Service *service);

static BOOL Initialize(Service *service, Identity identity);

static BOOL MessageHandle(Service *service, Request *msg);

static TaskConfig GetTaskConfig(Service *service);

static Service g_exampleService={

.GetName=GetName,

.Initialize=Initialize,

.MessageHandle=MessageHandle,

.GetTaskConfig=GetTaskConfig

};

2. 建立Feature变量

这里定义Feature没有直接使用Feature进行定义，而是使用了源码示例中的另外一种方式，即同类型定义。

typedef struct DemoApi{

INHERIT_IUNKNOWN;

BOOL (*AsyncCall)(IUnknown *iUnknown, const char *buff);

BOOL (*SyncCall)(IUnknown *iUnknown,struct Payload *payload);

} DemoApi;

typedef struct DemoFeature{

INHERIT_FEATURE;

INHERIT_IUNKNOWNENTRY(DemoApi);

Identity identity;

} DemoFeature;

static BOOL AsyncCall(IUnknown *iUnknown, const char *body);

static BOOL SyncCall(IUnknown *iUnknown, struct Payload *payload);

static const char* FEATURE_GetName(Feature *feature);

static void FEATURE_OnInitialize(Feature *feature, Service* parent, Identity identity);

static void FEATURE_OnStop(Feature *feature, Identity identity);

static BOOL FEATURE_OnMessage(Feature *feature, Request *request);

3. 注册Service&Feature

SAMGR_GetInstance()->RegisterService(&g_exampleService);

SAMGR_GetInstance()->RegisterFeature(EXAMPLE_SERVICE,(Feature*)&g_example);

SAMGR_GetInstance()->RegisterFeatureApi(EXAMPLE_SERVICE,EXAMPLE_FEATURE,GET_IUNKNOWN(g_example));

4. 添加初始化

SYSEX_FEATURE_INIT(Init);

作完以上步骤后编译烧写到wifi-iot开发板后就能够看到Feature能被正常初始化了。固然上面只是贴出了核心代码，声明的方法仍是须要再实现一下的，下面是完整的代码。

#include

#include

#include

#include

#include

#include

#include "iunknown.h"

#include "feature.h"

#include "service.h"

#include "samgr_lite.h"

#include "time_adapter.h"

#include "discovery_service.h"

#define EXAMPLE_SERVICE "example"

#define EXAMPLE_FEATURE "example"

struct Payload{

int id;

const char *name;

int value;

};

typedef struct DemoApi{

INHERIT_IUNKNOWN;

BOOL (*AsyncCall)(IUnknown *iUnknown, const char *buff);

BOOL (*SyncCall)(IUnknown *iUnknown,struct Payload *payload);

} DemoApi;

typedef struct DemoFeature{

INHERIT_FEATURE;

INHERIT_IUNKNOWNENTRY(DemoApi);

Identity identity;

} DemoFeature;

static BOOL AsyncCall(IUnknown *iUnknown, const char *body);

static BOOL SyncCall(IUnknown *iUnknown, struct Payload *payload);

static const char* FEATURE_GetName(Feature *feature);

static void FEATURE_OnInitialize(Feature *feature, Service* parent, Identity identity);

static void FEATURE_OnStop(Feature *feature, Identity identity);

static BOOL FEATURE_OnMessage(Feature *feature, Request *request);

static int g_regStep=0;

static const char *GetName(Service *service)

{

(void)service;

printf("GetService name:");

return EXAMPLE_SERVICE;

}

static BOOL Initialize(Service *service, Identity identity)

{

(void)identity;

printf("[Boot Test][TaskID:%p][Step:%d][Reg Finish S:%s]Time: %llu!\n",

osThreadGetId(), g_regStep++, service->GetName(service), SAMGR_GetProcessTime());

return TRUE;

}

static BOOL MessageHandle(Service *service, Request *msg)

{

printf("[Boot Test][TaskID:%p][Step:%d][S:%s] msgId \n",

osThreadGetId(), g_regStep++, service->GetName(service), msg->msgId);

return FALSE;

}

static TaskConfig GetTaskConfig(Service *service)

{

(void)service;

TaskConfig config = {LEVEL_HIGH, PRI_ABOVE_NORMAL,

0x400, 2, SHARED_TASK};

return config;

}

static Service g_exampleService={

.GetName=GetName,

.Initialize=Initialize,

.MessageHandle=MessageHandle,

.GetTaskConfig=GetTaskConfig

};

static DemoFeature g_example={

.GetName=FEATURE_GetName,

.OnInitialize = FEATURE_OnInitialize,

.OnStop = FEATURE_OnStop,

.OnMessage = FEATURE_OnMessage,

DEFAULT_IUNKNOWN_ENTRY_BEGIN,

.AsyncCall=AsyncCall,

.SyncCall=SyncCall,

DEFAULT_IUNKNOWN_ENTRY_END,

.identity = {-1, -1, NULL}

};

static const char* FEATURE_GetName(Feature *feature)

{

printf("get feature name.");

(void)feature;

return EXAMPLE_FEATURE;

}

static void FEATURE_OnInitialize(Feature *feature, Service *parent, Identity identity)

{

printf("Register Test,Oninit1");

(void)parent;

DemoFeature *demoFeature=(DemoFeature*)feature;

demoFeature->identity=identity;

printf("Register Test,Oninit");

}

static void FEATURE_OnStop(Feature *feature, Identity identity)

{

(void)feature;

(void)identity;

g_example.identity.queueId = NULL;

g_example.identity.featureId = -1;

g_example.identity.serviceId = -1;

}

static BOOL FEATURE_OnMessage(Feature *feature, Request *request)

{

(void)feature;

(void)request;

printf("[LPC Test][TaskID:%p][Step:%d][OnMessage S:%s, F:%s] Inner Error! \n",

osThreadGetId(), g_regStep++, EXAMPLE_SERVICE, feature->GetName(feature));

return FALSE;

}

static BOOL SyncCall(IUnknown *iUnknown, struct Payload *payload)

{

(void)iUnknown;

if (payload != NULL && payload->id >= 0 && payload->name != NULL) {

printf("[LPC Test][TaskID:%p][Step:%d][SyncCall API] Id:%d, name:%s, value:%d \n",

osThreadGetId(), g_regStep++, payload->id, payload->name, payload->value);

return TRUE;

}

printf("[LPC Test][TaskID:%p][Step:%d][SyncCall API] Input Error! \n", osThreadGetId(), g_regStep++);

return FALSE;

}

static BOOL AsyncCall(IUnknown *iUnknown, const char *body)

{

Request request = {.msgId = 1, .msgValue = 0};

request.len = (uint32_t)(strlen(body) + 1);

request.data = malloc(request.len);

if (request.data == NULL) {

return FALSE;

}

if (strcpy_s(request.data, request.len, body) != EOK) {

free(request.data);

return FALSE;

}

DemoFeature *feature = GET_OBJECT(iUnknown, DemoFeature, iUnknown);

printf("[LPC Test][TaskID:%p][Step:%d][AsyncCall API] Send request! \n", osThreadGetId(), g_regStep++);

return SAMGR_SendRequest(&feature->identity, &request, NULL);

}

static void OnPublishSuccess(int32_t publishId){

printf("demo service publish success.%d",publishId);

}

static void onPublishFail(int32_t publishId, PublishFailReason reason)

{

printf("OnPublishFail.%d,%d",publishId,(int32_t)reason);

}

//初始化工做，注册Service后，再注册Feature

static void Init(void)

{

SAMGR_GetInstance()->RegisterService(&g_exampleService);

SAMGR_GetInstance()->RegisterFeature(EXAMPLE_SERVICE,(Feature*)&g_example);

SAMGR_GetInstance()->RegisterFeatureApi(EXAMPLE_SERVICE,EXAMPLE_FEATURE,GET_IUNKNOWN(g_example));

printf("[Register Test][TaskID:%d][Step:%d][Reg S:%s, F:%s] Time: %llu!\n",

osThreadGetId(),g_regStep++,EXAMPLE_SERVICE,EXAMPLE_FEATURE,SAMGR_GetProcessTime());

}

//使用此方式初始化Feature

SYSEX_FEATURE_INIT(Init);

做者：mb5f8960971f61a

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