Get started

按钮添加标签

/*** @brief 按钮事件回调函数* @param e 
*/
void btn_event_cb(lv_event_t* e)
{lv_event_code_t code = lv_event_get_code(e);lv_obj_t* btn = lv_event_get_current_target(e);if (LV_EVENT_CLICKED == code) {static uint8_t cnt = 0;cnt++;lv_obj_t* label = lv_obj_get_child(btn, 0);lv_label_set_text_fmt(label, "Button:%d", cnt);}
}/*** @brief Get started demo* @param  
*/
void lv_demo_get_started(void)
{lv_obj_t * btn = lv_btn_create(lv_scr_act());lv_obj_set_size(btn, 100, 50);lv_obj_set_pos(btn, 150, 100);lv_obj_add_event_cb(btn, btn_event_cb, LV_EVENT_ALL, NULL);lv_obj_t* label = lv_label_create(btn);lv_label_set_text(label, "Button:");lv_obj_center(label);
}

按钮添加风格

static lv_style_t style_btn;
static lv_style_t style_btn_pressed;
static lv_style_t style_btn_red;static lv_color_t darken(const lv_color_filter_dsc_t* dsc, lv_color_t color, lv_opa_t opa)
{LV_UNUSED(dsc);return lv_color_darken(color, opa);
}static void style_init(void)
{// 创建一个简单按钮风格lv_style_init(&style_btn);lv_style_set_radius(&style_btn, 10);lv_style_set_bg_opa(&style_btn, LV_OPA_COVER);lv_style_set_bg_color(&style_btn, lv_palette_lighten(LV_PALETTE_GREY, 3));lv_style_set_bg_grad_color(&style_btn, lv_palette_main(LV_PALETTE_GREY));lv_style_set_bg_grad_dir(&style_btn, LV_GRAD_DIR_VER);lv_style_set_border_color(&style_btn, lv_color_black());lv_style_set_border_opa(&style_btn, LV_OPA_20);lv_style_set_border_width(&style_btn, 2);lv_style_set_text_color(&style_btn, lv_color_black());// 创建按下状态风格static lv_color_filter_dsc_t color_filter;lv_color_filter_dsc_init(&color_filter, darken);lv_style_init(&style_btn_pressed);lv_style_set_color_filter_dsc(&style_btn_pressed, &color_filter);lv_style_set_color_filter_opa(&style_btn_pressed, LV_OPA_20);// 创建红色风格，仅改变一些颜色lv_style_init(&style_btn_red);lv_style_set_bg_color(&style_btn_red, lv_palette_main(LV_PALETTE_RED));lv_style_set_bg_grad_color(&style_btn_red, lv_palette_lighten(LV_PALETTE_RED, 3));
}void lv_demo_get_started2(void)
{/* Initialize the style */style_init();lv_obj_t* btn = lv_btn_create(lv_scr_act());lv_obj_remove_style_all(btn);lv_obj_set_size(btn, 120, 50);lv_obj_set_pos(btn, 10, 10);lv_obj_add_style(btn, &style_btn, 0); // LV_STATE_DEFAULTlv_obj_add_style(btn, &style_btn_pressed, LV_STATE_PRESSED);/* Add a label to the button */lv_obj_t* label = lv_label_create(btn);lv_label_set_text(label, "Button");lv_obj_center(label);/* Create another button and use the red style too */lv_obj_t* btn2 = lv_btn_create(lv_scr_act());lv_obj_remove_style_all(btn2);  /* Remove the styles coming from the theme */lv_obj_set_size(btn2, 120, 50);lv_obj_set_pos(btn2, 10, 80);lv_obj_add_style(btn2, &style_btn, 0);lv_obj_add_style(btn2, &style_btn_red, 0);lv_obj_add_style(btn2, &style_btn_pressed, LV_STATE_PRESSED);lv_obj_set_style_radius(btn2, LV_RADIUS_CIRCLE, 0);label = lv_label_create(btn2);lv_label_set_text(label, "Button 2");lv_obj_center(label);}

滑动条值显示

static lv_obj_t* label;
static void slider_event_cb(lv_event_t* e)
{lv_obj_t* slider = lv_event_get_target(e);/* Refresh the text */lv_label_set_text_fmt(label, "%d", lv_slider_get_value(slider));lv_obj_align_to(label, slider, LV_ALIGN_OUT_TOP_MID, 0, -15);
}void lv_demo_get_started3(void)
{/* Create a slider in the center of the display */lv_obj_t* slider = lv_slider_create(lv_scr_act());lv_obj_set_width(slider, 200);  /*  Set the width */lv_obj_center(slider);  /* Align to the center of the parent (screen) */lv_obj_add_event_cb(slider, slider_event_cb, LV_EVENT_VALUE_CHANGED, NULL);label = lv_label_create(lv_scr_act());lv_label_set_text(label, "0");lv_obj_align_to(label, slider, LV_ALIGN_OUT_TOP_MID, 0, -15); /* Align top of the slider */
}

Styles

Size styles

void lv_demo_style_1(void)
{static lv_style_t style;lv_style_init(&style);lv_style_set_radius(&style, 5);/* Make a gradient */lv_style_set_width(&style, 150);lv_style_set_height(&style, LV_SIZE_CONTENT);lv_style_set_pad_ver(&style, 20);lv_style_set_pad_left(&style, 5);lv_style_set_x(&style, lv_pct(50));lv_style_set_y(&style, 80);lv_obj_t* obj = lv_obj_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_obj_t* label = lv_label_create(obj);lv_label_set_text(label, "Hello");
}

Background styles

渐变方向：

• LV_GRAD_DIR_VER：垂直方向
• LV_GRAD_DIR_HOR：水平方向

void lv_demo_style_2(void)
{static lv_style_t style;lv_style_init(&style);lv_style_set_radius(&style, 5);lv_style_set_bg_opa(&style, LV_OPA_COVER);static lv_grad_dsc_t grad;grad.dir = LV_GRAD_DIR_VER; // 渐变方向grad.stops_count = LV_GRADIENT_MAX_STOPS;grad.stops[0].color = lv_palette_lighten(LV_PALETTE_GREY, 1); // 颜色1grad.stops[1].color = lv_palette_main(LV_PALETTE_BLUE); // 颜色2grad.stops[0].frac = 128; // 1~255 grad.stops[1].frac = 192; // 1~255 lv_style_set_bg_grad(&style, &grad);lv_obj_t* obj = lv_obj_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_obj_center(obj);lv_obj_t* label = lv_label_create(obj);lv_label_set_text(label, "Hello");lv_obj_center(label);
}

Border styles

void lv_demo_style_3(void) // Border styles
{static lv_style_t style;lv_style_init(&style);/* Set a background color and a radius */lv_style_set_radius(&style, 5);lv_style_set_bg_opa(&style, LV_OPA_COVER);lv_style_set_bg_color(&style, lv_palette_lighten(LV_PALETTE_GREY, 1));/* Add border to the bottom+right */lv_style_set_border_color(&style, lv_palette_main(LV_PALETTE_BLUE));lv_style_set_border_width(&style, 5);lv_style_set_border_opa(&style, LV_OPA_50);lv_style_set_border_side(&style, LV_BORDER_SIDE_BOTTOM | LV_BORDER_SIDE_RIGHT);/* Create an object with the new style */lv_obj_t* obj = lv_obj_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_obj_center(obj);}

Outline styles

void lv_demo_style_4(void) // Outline styles
{static lv_style_t style;lv_style_init(&style);/* Set a background color and radius */lv_style_set_radius(&style, 5);lv_style_set_bg_opa(&style, LV_OPA_COVER);lv_style_set_bg_color(&style, lv_palette_lighten(LV_PALETTE_GREY, 1));/* Add outline */lv_style_set_outline_width(&style, 2);lv_style_set_outline_color(&style, lv_palette_main(LV_PALETTE_BLUE));lv_style_set_outline_pad(&style, 8);/* Create an object with the new style */lv_obj_t* obj = lv_obj_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_obj_center(obj);
}

Shadow styles

void lv_demo_style_5(void) // Shadow styles
{static lv_style_t style;lv_style_init(&style);/* Set a background color and a radius */lv_style_set_radius(&style, 5);lv_style_set_bg_opa(&style, LV_OPA_COVER);lv_style_set_bg_color(&style, lv_palette_lighten(LV_PALETTE_GREY, 1));/* Add a shadow */lv_style_set_shadow_width(&style, 55);lv_style_set_shadow_color(&style, lv_palette_main(LV_PALETTE_BLUE));// lv_style_set_shadow_ofs_x(&style, 10);// lv_style_set_shadow_ofs_y(&style, 20);/* Create an object with the new style */lv_obj_t* obj = lv_obj_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_obj_center(obj);
}

设置shadow offset的效果：
lv_style_set_shadow_ofs_x(&style, 10);
lv_style_set_shadow_ofs_y(&style, 20);

Image styles

const uint8_t img_cogwheel_argb_map[] = {
/Pixel format: Alpha 8 bit, Red: 3 bit, Green: 3 bit, Blue: 2 bit/
0xff, 0x00, 0xff, 0x00, 0xff, 0x00, 0xff, 0x00, 0xff, 0x00, 0xff, 0x00, 0xff,
…
}
const lv_img_dsc_t img_cogwheel_argb = {
.header.always_zero = 0,
.header.w = 100,
.header.h = 100,
.data_size = 10000 * LV_IMG_PX_SIZE_ALPHA_BYTE,
.header.cf = LV_IMG_CF_TRUE_COLOR_ALPHA,
.data = img_cogwheel_argb_map,
};

void lv_demo_style_6(void) // Image styles
{lv_style_t style;lv_style_init(&style);/* Set a background color and a radius */lv_style_set_radius(&style, 5);lv_style_set_bg_opa(&style, LV_OPA_COVER);lv_style_set_bg_color(&style, lv_palette_lighten(LV_PALETTE_GREY, 1));lv_style_set_border_width(&style, 2);lv_style_set_border_color(&style, lv_palette_main(LV_PALETTE_BLUE));lv_style_set_img_recolor(&style, lv_palette_main(LV_PALETTE_BLUE));lv_style_set_img_recolor_opa(&style, LV_OPA_50);lv_style_set_transform_angle(&style, 300);/* Create an object with the new style */lv_obj_t* obj = lv_obj_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);LV_IMG_DECLARE(img_cogwheel_argb);lv_img_set_src(obj, &img_cogwheel_argb);lv_obj_center(obj);
}

Arc styles

void lv_demo_style_7(void) // Arc styles
{static lv_style_t style;lv_style_init(&style);lv_style_set_arc_width(&style, 4);lv_style_set_arc_opa(&style, LV_OPA_COVER);lv_style_set_arc_color(&style, lv_palette_main(LV_PALETTE_RED));/* Create an object with the new style */lv_obj_t* obj = lv_arc_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_obj_center(obj);
}

Text styles

void lv_demo_style_8(void) // Text styles
{static lv_style_t style;lv_style_init(&style);lv_style_set_radius(&style, 5);lv_style_set_bg_opa(&style, LV_OPA_COVER);lv_style_set_bg_color(&style, lv_palette_lighten(LV_PALETTE_GREY, 2));lv_style_set_border_width(&style, 2);lv_style_set_border_color(&style, lv_palette_main(LV_PALETTE_BLUE));lv_style_set_pad_all(&style, 10);lv_style_set_text_color(&style, lv_palette_main(LV_PALETTE_BLUE));lv_style_set_text_letter_space(&style, 5);lv_style_set_text_line_space(&style, 20);lv_style_set_text_decor(&style, LV_TEXT_DECOR_UNDERLINE);/* Create an object with the new style */lv_obj_t* obj = lv_label_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);lv_label_set_text(obj, "Text of \n""a label");lv_obj_center(obj);}

Line styles

void lv_demo_style_9(void) // Line styles
{static lv_style_t style;lv_style_init(&style);lv_style_set_line_color(&style, lv_palette_main(LV_PALETTE_GREY));lv_style_set_line_width(&style, 6);lv_style_set_line_rounded(&style, true);/* Create an object with the new style */lv_obj_t* obj = lv_line_create(lv_scr_act());lv_obj_add_style(obj, &style, 0);static lv_point_t p[] = { {10, 30}, {30, 50}, {100, 0} };lv_line_set_points(obj, p, 3);lv_obj_center(obj);}