emwin怎么绘制SD卡存储的图片？

发布于 2020-01-31 15:41:49 浏览：1397 订阅该版

5 个回答

Rses_001 2020-01-31

这家伙很懒，什么也没写！

wacalei 2020-01-31

这家伙很懒，什么也没写！

Rses_001 2020-01-31

这家伙很懒，什么也没写！

wacalei 2020-01-31

这家伙很懒，什么也没写！

>就像你截图那样，emwin这个函数就是要获得指定偏移量下的指定数量的数据
>你就仿照他的写法

---

int APP_GetData(void * p, const U8 ** ppData, unsigned NumBytes, U32 Off) {
	static char _acBuffer[250];
	static U32 read_addr,temp;
	int  phFile;
	int NumBytesRead;
	phFile = *(int *)p;
	//
	// Check buffer size
	//
	if (NumBytes > sizeof(_acBuffer)) {
	NumBytes = sizeof(_acBuffer);
	}
	//
	// Set file pointer to the required position
	//
	if(Off == 1) read_addr = 0;
	else read_addr = Off;
	lseek(phFile,Off,SEEK_SET);
	//
	// Read data into buffer
	//
	NumBytesRead = read(phFile, _acBuffer, NumBytes);
	//
	// Set data pointer to the beginning of the buffer
	//
	*ppData = (const U8*)_acBuffer;
	//
	// Return number of available bytes
	//
	return NumBytesRead;
}
void emwin_test(void)
{
	uint8_t x,y;
	__HAL_RCC_CRC_CLK_ENABLE();
    CRC_HandleTypeDef   CrcHandle;
    CrcHandle.Instance = CRC; 
    HAL_CRC_Init(&CrcHandle);
    GUI_Init();	
	GUI_SetBkColor(GUI_BLUE);
	GUI_Clear();
	
	/**************************************************/
	int fd = open("/Pictures/bmp/-7b8598a39009aeea.bmp", O_RDONLY);
    if (fd >= 0)
    {
		rt_kprintf("file open OK\n");
		GUI_BMP_DrawScaledEx(APP_GetData,&fd,0,0,1,1);
		close(fd);
		rt_kprintf("close file\n");
    }
	else
	{
		rt_kprintf("file open file\n");
	}
}
INIT_APP_EXPORT(emwin_test);

shell:
 \ | /
- RT -     Thread Operating System
 / | \     4.0.1 build Jan 31 2020
 2006 - 2019 Copyright by rt-thread team
SD file system initialization done!
[I/sensor] rt_sensor init success
[I/sensor] rt_sensor init success
file open OK
close file
msh />

如上所示，我的确这么做了。但是屏幕上并没有显示任何图片，我昨天用工具转换成流文件然后使用GUI_DrawBitmapMag这个函数显示是没问题的，至少可以排除移植驱动的问题