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在开发STM32LiteOS系统应用时，任务编程是核心技能之一。本文将指导读者完成一个简单的任务开发循序渐进地开展工作。

首先，在工程目录下新建一个Ex_task.c文件，并在其中添加如下的代码片段：

# include "stm32l4xx_hal.h"# include "gpio.h"# include "los_demo_debug.h"# include "los_inspect_entry.h"# include "los_typedef.h"# include "los_queue.h"# include "los_task.h"static UINT32 g_uwTskHiID;static UINT32 g_uwTskLoID;#define TSK_PRIOR_HI 4#define TSK_PRIOR_LO 5static UINT32 Example_TaskHi_1(VOID){    UINT32 uwRet = LOS_OK;    dprintf("Enter TaskHi Handler.\r\n");        /*延时5个Tick，延时后该任务会挂起，执行剩余任务中高优先级的任务(g_uwTskLoID任务)*/    uwRet = LOS_TaskDelay(5);    if (uwRet != LOS_OK) {        dprintf("Delay Task Failed.\r\n");        return LOS_NOK;    }        /*2个tick时间到了后，该任务恢复，继续执行*/    dprintf("Enter TaskHi LOS_TaskDelay Done.\r\n");        /*挂起自身任务*/    uwRet = LOS_TaskSuspend(g_uwTskHiID);    if (uwRet != LOS_OK) {        dprintf("Suspend TaskHi Failed.\r\n");        uwRet = LOS_InspectStatusSetByID(LOS_INSPECT_TASK, LOS_INSPECT_STU_ERROR);        if (uwRet != LOS_OK) {            dprintf("Set Inspect Status Err\n");        }        return LOS_NOK;    }        dprintf("TaskHi LOS_TaskResume Success.\r\n");    uwRet = LOS_InspectStatusSetByID(LOS_INSPECT_TASK, LOS_INSPECT_STU_SUCCESS);    if (uwRet != LOS_OK) {        dprintf("Set Inspect Status Err\n");    }        /*删除任务*/    if (LOS_OK != LOS_TaskDelete(g_uwTskHiID)) {        dprintf("TaskHi delete failed .\n");        return LOS_NOK;    }        return LOS_OK;}/*低优先级任务入口函数*/static UINT32 Example_TaskLo_1(VOID){    UINT32 uwRet;    dprintf("Enter TaskLo Handler.\r\n");        /*延时10个Tick，延时后该任务会挂起，执行剩余任务中高优先级的任务(背景任务)*/    uwRet = LOS_TaskDelay(10);    if (uwRet != LOS_OK) {        dprintf("Delay TaskLo Failed.\r\n");        return LOS_NOK;    }        dprintf("TaskHi LOS_TaskSuspend Success.\r\n");        /*恢复被挂起的任务g_uwTskHiID*/    uwRet = LOS_TaskResume(g_uwTskHiID);    if (uwRet != LOS_OK) {        dprintf("Resume TaskHi Failed.\r\n");        uwRet = LOS_InspectStatusSetByID(LOS_INSPECT_TASK, LOS_INSPECT_STU_ERROR);        if (uwRet != LOS_OK) {            dprintf("Set Inspect Status Err\n");        }        return LOS_NOK;    }        /*删除任务*/    if (LOS_OK != LOS_TaskDelete(g_uwTskLoID)) {        dprintf("TaskLo delete failed .\n");        return LOS_NOK;    }        return LOS_OK;} UINT32 Example_Entry(VOID) {     UINT32 uwRet = LOS_OK;     TSK_INIT_PARAM_S stInitParam = {0};     dprintf("LOS_TaskLock() Success!\r\n");          stInitParam.pfnTaskEntry = (TSK_ENTRY_FUNC)Example_TaskHi_1;     stInitParam.usTaskPrio = TSK_PRIOR_HI;     stInitParam.pcName = "Task1";     stInitParam.uwStackSize = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;          uwRet = LOS_TaskCreate(&g_uwTskHiID, &stInitParam);     if (uwRet != LOS_OK) {         printf("Example_Task1 create Failed!\r\n");         return LOS_NOK;     }          dprintf("Example_TaskHi create Success!\r\n");          stInitParam.pfnTaskEntry = (TSK_ENTRY_FUNC)Example_TaskLo_1;     stInitParam.usTaskPrio = TSK_PRIOR_LO;     stInitParam.pcName = "Task2";     stInitParam.uwStackSize = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;          uwRet = LOS_TaskCreate(&g_uwTskLoID, &stInitParam);     if (uwRet != LOS_OK) {         printf("Example_Task2 create Failed!\r\n");         return LOS_NOK;     }          dprintf("Example_TaskLo create Success!\r\n");          return uwRet; }

接下来，返回到项目主文件（main.c），在其中添加以下代码：

.../* Private function prototypes -----------------------------------------------*/void SystemClock_Config(void);/* USER CODE BEGIN PFP */UINT32 Example_Entry(VOID);/* USER CODE END PFP */.../* USER CODE BEGIN 2 */if (LOS_OK != LOS_KernelInit()) {    return LOS_NOK;}Example_Entry();LOS_Start();/* USER CODE END 2 */

完成代码开发后，保存文件并进行编译和运行，确认系统按预期工作。如果遇到问题，请仔细检查任务创建、延时、任务挂起及恢复等关键操作的实现是否符合LiteOS任务管理规范。

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