lvgl 简易计算器

你想了解如何使用 LVGL 创建一个简易计算器吗？下面是一个使用 LVGL 创建简易计算器的示例代码：

#include <lvgl.h>

lv_obj_t *textbox;
lv_obj_t *label;
lv_obj_t *btns[16];

void btn_click_event(lv_obj_t *btn, lv_event_t event)
{
    if (event == LV_EVENT_CLICKED) {
        char txt[2];
        lv_btn_get_text(btn, txt);
        if (txt[0] == '=') {
            char result[16];
            lv_textarea_get_text(textbox, result, sizeof(result));
            int num1, num2;
            char op;
            sscanf(result, "%d %c %d", &num1, &op, &num2);
            int res;
            switch (op) {
                case '+':
                    res = num1 + num2;
                    break;
                case '-':
                    res = num1 - num2;
                    break;
                case '*':
                    res = num1 * num2;
                    break;
                case '/':
                    res = num1 / num2;
                    break;
                default:
                    res = 0;
                    break;
            }
            sprintf(result, "%d", res);
            lv_label_set_text(label, result);
        } else {
            lv_textarea_add_char(textbox, txt[0]);
        }
    }
}

void create_calculator(lv_obj_t *parent)
{
    lv_obj_t *container = lv_cont_create(parent, NULL);
    lv_obj_set_style_local_bg_color(container, LV_CONT_PART_MAIN, LV_COLOR_WHITE);

    textbox = lv_textarea_create(container, NULL);
    lv_textarea_set_one_line(textbox, true);
    lv_obj_align(textbox, container, LV_ALIGN_IN_TOP_MID, 0, 10);

    label = lv_label_create(container, NULL);
    lv_obj_align(label, textbox, LV_ALIGN_OUT_BOTTOM_MID, 0, 10);

    const char *btn_labels[16] = {
        "7", "8", "9", "/",
        "4", "5", "6", "*",
        "1", "2", "3", "-",
        "0", ".", "=", "+"
    };

    for (int i = 0; i < 16; i++) {
        btns[i] = lv_btn_create(container, NULL);
        lv_obj_set_event_cb(btns[i], btn_click_event);
        lv_obj_t *label = lv_label_create(btns[i], NULL);
        lv_label_set_text(label, btn_labels[i]);
    }

    lv_obj_set_pos(btns[0], 0, 100);
    lv_obj_set_pos(btns[1], 80, 100);
    lv_obj_set_pos(btns[2], 160, 100);
    lv_obj_set_pos(btns[3], 240, 100);
    lv_obj_set_pos(btns[4], 0, 180);
    lv_obj_set_pos(btns[5], 80, 180);
    lv_obj_set_pos(btns[6], 160, 180);
    lv_obj_set_pos(btns[7], 240, 180);
    lv_obj_set_pos(btns[8], 0, 260);
    lv_obj_set_pos(btns[9], 80, 260);
    lv_obj_set_pos(btns[10], 160, 260);
    lv_obj_set_pos(btns[11], 240, 260);
    lv_obj_set_pos(btns[12], 0, 340);
    lv_obj_set_pos(btns[13], 80, 340);
    lv_obj_set_pos(btns[14], 160, 340);
    lv_obj_set_pos(btns[15], 240, 340);
}

int main(void)
{
    lv_init();

    lv_obj_t *scr = lv_scr_act();
    create_calculator(scr);

    while (1) {
        lv_task_handler();
        usleep(5000);
    }

    return 0;
}

这个示例代码使用了 LVGL 库来创建一个简易计算器。它使用了文本框、标签和按钮来实现计算器的功能。你可以根据需要进行修改和扩展。记得在编译和运行代码之前，确保已经正确配置好了 LVGL 库。

希望这可以帮助到你！如果还有其他问题，请随时提问。