使用函数lv_img_get_src获取bmp图片参数有误

LVGL LVGL9.x
,
1

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/**
 ******************************************************************************
 * file    lesson_2_3_1.c
 * author  百问科技
 * version V1.0
 * date    2024-4-25
 * brief	Lesson 2-3-1 demo
 ******************************************************************************
 * Change Logs:
 * Date           Author          Notes
 * 2024-4-25     zhouyuebiao     First version
 ******************************************************************************
 * @attention
 *
 * Copyright (C) 2008-2024 深圳百问网科技有限公司<https://www.100ask.net/>
 * All rights reserved
 *
 ******************************************************************************
 */


/*********************
 *      INCLUDES
 *********************/
#include "../../lv_100ask_lesson_demos.h"

#if LV_USE_LESSON_DEMO_2_3_1

#include "lesson_2_3_1.h"


/*********************
 *      DEFINES
 *********************/


/**********************
 *  STATIC VARIABLES
 **********************/

#define CANVAS_WIDTH 240
#define CANVAS_HEIGHT 320
void lesson_2_3_1(void)
{
    #if 0
    lv_obj_t * obj;
    lv_obj_t * label;

    obj = lv_obj_create(lv_screen_active());
    lv_obj_set_size(obj, LV_PCT(40), LV_PCT(30));
    lv_obj_align(obj, LV_ALIGN_CENTER, 0, 0);

    label = lv_label_create(obj);
    lv_label_set_text_fmt(label, "Hello, LVGL!\nLVGL V%d.%d.%d\nhttps://www.100ask.net", lv_version_major(), lv_version_minor(), lv_version_patch());
    lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
    #else
    /*Create a buffer for the canvas*/
    static uint8_t cbuf[LV_CANVAS_BUF_SIZE(CANVAS_WIDTH, CANVAS_HEIGHT, 32, LV_DRAW_BUF_STRIDE_ALIGN)];
    lv_obj_t * canvas = lv_canvas_create(lv_scr_act());
    lv_canvas_set_buffer(canvas, cbuf, CANVAS_WIDTH, CANVAS_HEIGHT, LV_COLOR_FORMAT_ARGB8888);
    lv_obj_t * img = lv_img_create(canvas);
    lv_image_set_src(img, "D:0.bmp");
    //lv_image_set_src(img, "D:wifi1.png");
    lv_obj_center(img);
    // 获取图片的内部数据
    const lv_img_dsc_t *img_dsc = lv_img_get_src(img);
    if(img_dsc == NULL || img_dsc->data == NULL) {
        // 加载或解码失败
        lv_obj_del(img); // 删除图像对象
        return -1;
    }
	printf("img_dsc->header.h=[%u] img_dsc->header.w=[%u]\n", img_dsc->header.h, img_dsc->header.w);
	printf("img_dsc->header.cf=[%u]\n", img_dsc->header.cf);
    printf("img_dsc->data_size=[%u]\n", img_dsc->data_size);

    static lv_style_t style;
    lv_style_init(&style);
    lv_font_t * font = lv_tiny_ttf_create_file("D:Normal.ttf", 48);
    lv_style_set_text_font(&style, font);
    lv_style_set_text_align(&style, LV_TEXT_ALIGN_CENTER);

    lv_obj_t *obj;
    obj = lv_label_create(img);
    lv_obj_add_style(obj, &style, 0);
    lv_label_set_text(obj, "星期一");
    lv_obj_center(obj);

    printf("img_dsc->header.h=[%u] img_dsc->header.w=[%u]\n", img_dsc->header.h, img_dsc->header.w);
    printf("img_dsc->header.cf=[%u]\n", img_dsc->header.cf);
    printf("img_dsc->data_size=[%u]\n", img_dsc->data_size);

    lv_image_dsc_t * image_dsc = lv_canvas_get_image(canvas);

    printf("img_dsc->header.h=[%u] img_dsc->header.w=[%u]\n", image_dsc->header.h, image_dsc->header.w);
    printf("img_dsc->header.cf=[%u]\n", image_dsc->header.cf);
    printf("img_dsc->data_size=[%u]\n", image_dsc->data_size);
    #endif

#if 0
    //obj = lv_obj_create(lv_screen_active());
    //lv_obj_set_size(obj, LV_PCT(30), LV_PCT(30));
    //lv_obj_align(obj, LV_ALIGN_CENTER, 0, 0);

    obj = lv_obj_create(lv_layer_top());
    lv_obj_set_size(obj, LV_PCT(35), LV_PCT(25));
    lv_obj_align(obj, LV_ALIGN_CENTER, 0, 0);

    obj = lv_obj_create(lv_layer_sys());
    lv_obj_set_size(obj, LV_PCT(30), LV_PCT(20));
    lv_obj_align(obj, LV_ALIGN_CENTER, 0, 0);
#endif
}


#endif /* LV_USE_LESSON_DEMO_2_3_1 */
2

目前使LVGLv9.1课程提供的PC模拟器去跑，在lesson_2_3_1上修改的

3

最终想要实现的功能是加载bmp（rgb888）图片作为背景图片，然后加载字库叠加文字和png图标，叠加后转为rgb888数据，并不需要直接显示输出画面。这个rgb888的数据要如何获取转换

4
  1. lv_image_get_src 获取到的是图像解码后的源数据 （点击查看代码），并没有w、h这些数据，要获取宽高可以使用lv_obj_get_width\lv_obj_get_height 或者 这样获取

img= lv_img_create(canvas);
lv_image_set_src(img, "D:0.bmp");
lv_image_t * image= (lv_image_t *)img;
printf("image->w: %d, image->h: %d\n", image->w, image->h);
  1. 父子对象之间只是图层关系，没有实际上的修改，如果你想获取在图片之上的修改的效果(比如给图片添加水印效果)，参考LVGL的快照：https://lvgl.100ask.net/master/others/snapshot.html