小弟我做了一个壁纸的应用程序，就是把应用程序里面的图片保存到本地文件夹里面。小弟我写完后再模拟器上运行正常，但是把它移植到真机上就保存失败？这是为什么

void SetName(belle *pMe){    char time[50];        char temGroup[10];    char temGroup1[10];    char temGroup2[10];    char temGroup3[10];    char temGroup4[10];    char temGroup5[10];            JulianType rJulianDate;        GETJULIANDATE(0, &rJulianDate);        DBGPRINTF("wYear=%d,wMonth=%d,wDay=%d,wHour=%d,wMinute=%d,wSecond=%d\n",rJulianDate.wYear,rJulianDate.wMonth,rJulianDate.wDay,rJulianDate.wHour,rJulianDate.wMinute,rJulianDate.wSecond);        SPRINTF((char*)temGroup, "%d", rJulianDate.wYear);        SPRINTF((char*)temGroup1, "%d", rJulianDate.wMonth);        SPRINTF((char*)temGroup2, "%d", rJulianDate.wDay);                SPRINTF((char*)temGroup3, "%d", rJulianDate.wHour);        SPRINTF((char*)temGroup4, "%d", rJulianDate.wMinute);        SPRINTF((char*)temGroup5, "%d", rJulianDate.wSecond);        DBGPRINTF("%s-%s-%s-%s:%s:%s",temGroup,temGroup1,temGroup2,temGroup3,temGroup4,temGroup5);                MEMSET(time,0,sizeof(time));        STRCAT((char*)time,temGroup);        STRCAT((char*)time,temGroup1);        STRCAT((char*)time,temGroup2);        STRCAT((char*)time,temGroup3);        STRCAT((char*)time,temGroup4);        STRCAT((char*)time,temGroup5);        DBGPRINTF("=================%s",time);                MEMSET(pMe->savefilename,0,sizeof(pMe->savefilename));STRCAT(pMe->savefilename,"fs:/mod/10888/");STRCAT(pMe->savefilename,time);STRCAT(pMe->savefilename,".jpg");}void ReadFile(belle *pMe,const char *myfile,const char *savefile){        int count;    AEEFileInfo   pInfo;    AECHAR sh[20] ={'l','i','n','g'};     AECHAR ss[20] ={'s','s','s','s'};         pMe->pMyFile = IFILEMGR_OpenFile(pMe->pMyFileMgr,myfile,_OFM_READ);        if(pMe->pMyFile==NULL){            DBGPRINTF("ENTER pMe->pMyFile11 = NULL\n");        return;        }        IFILE_GetInfo(pMe->pMyFile,&pInfo);//读取文件大小    DBGPRINTF("pMe->pInfo->dwSize=%d\n",pInfo.dwSize);        pMe->mydata=(char *)MALLOC(pInfo.dwSize);//分配动态内存    if(pMe->mydata==NULL){        DBGPRINTF("mydata FAKL\n");    }        IFILE_Read(pMe->pMyFile,(void *)pMe->mydata,pInfo.dwSize);            IFILE_Release(pMe->pMyFile);        pMe->pMyFile = IFILEMGR_OpenFile(pMe->pMyFileMgr,savefile,_OFM_READWRITE);    if(pMe->pMyFile==NULL){        //pMe->pMyFile = IFILEMGR_OpenFile(pMe->pMyFileMgr,"fs:/mod/10888/myfile.jpg",_OFM_CREATE);        pMe->pMyFile = IFILEMGR_OpenFile(pMe->pMyFileMgr,savefile,_OFM_CREATE);if(pMe->pMyFile ==NULL){                IDISPLAY_DrawText(pMe->a.m_pIDisplay,AEE_FONT_NORMAL,ss,-1,20,60,NULL,IDF_ALIGN_CENTER);            return;        }            }    count = IFILE_Write(pMe->pMyFile,(void *)pMe->mydata,pInfo.dwSize);    if(0 == count)    {        IDISPLAY_DrawText(pMe->a.m_pIDisplay,AEE_FONT_NORMAL,sh,-1,20,20,NULL,IDF_ALIGN_CENTER);    }    IFILE_Release(pMe->pMyFile);          FREE(pMe->mydata);}