LED（指示灯） (lv_led)

Overview（概述）

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The LEDs are rectangle-like (or circle) Widgets whose brightness can be adjusted. With lower brightness the colors of the LED become darker.

LED（指示灯）是矩形（或圆形）部件。它的亮度可以调节。亮度降低时，LED的颜色会变暗。

Parts and Styles（部分和样式）

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LV_LED_PART_MAIN uses all the typical background style properties.

LV_LED_PART_MAIN 它使用所有典型的背景样式属性。

Usage（用法）

Color（颜色）

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You can set the color of the LED with lv_led_set_color(led, lv_color_hex(0xff0080)). This will be used as background color, border color, and shadow color.

可以使用函数 lv_led_set_color(led, lv_color_hex(0xff0080)) 设置 LED 的颜色。这将用作背景颜色、边框颜色和阴影颜色。

Brightness（亮度）

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You can set their brightness with lv_led_set_bright(led, bright). The brightness should be between 0 (darkest) and 255 (lightest).

可以使用函数 lv_led_set_bright(led, bright) 设置它们的亮度。亮度范围：0（最暗）- 255（最亮）。

Toggle（切换）

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Use lv_led_on(led) and lv_led_off(led) to set the brightness to a predefined ON or OFF value. The lv_led_toggle(led) toggles between the ON and OFF state.

You can set custom LED ON and OFF brightness values by defining macros LV_LED_BRIGHT_MAX and LV_LED_BRIGHT_MIN in your project. Their default values are 80 and 255. These too must be in the range [0..255].

使用函数 lv_led_on(led) 和 lv_led_off(led) 将亮度设置为预定义的ON或OFF值。函数:cpp:expr:lv_led_toggle(led) 就像开关，会让led在ON和OFF状态之间切换。

你可以通过在项目中定义宏 LV_LED_BRIGHT_MAX 和 LV_LED_BRIGHT_MIN 来设置自定义的 LED 亮起和熄灭时的亮度值。它们的默认值分别为 80 和 255。这两个值也必须处于 [0..255] 这个取值范围内。 .. _lv_led_events:

Events（事件）

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No special events are sent by LED Widgets.

Keys（按键）

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No Keys are processed by LED Widgets.

Learn more about Keys（按键）.

LED 部件不处理任何按键。

了解有关 Keys（按键）的更多内容。

Example

LED with custom style

#include "../../lv_examples.h"
#if LV_USE_LED && LV_BUILD_EXAMPLES

/**
 * Create LED's with different brightness and color
 */
void lv_example_led_1(void)
{
    /*Create a LED and switch it OFF*/
    lv_obj_t * led1  = lv_led_create(lv_screen_active());
    lv_obj_align(led1, LV_ALIGN_CENTER, -80, 0);
    lv_led_off(led1);

    /*Copy the previous LED and set a brightness*/
    lv_obj_t * led2  = lv_led_create(lv_screen_active());
    lv_obj_align(led2, LV_ALIGN_CENTER, 0, 0);
    lv_led_set_brightness(led2, 150);
    lv_led_set_color(led2, lv_palette_main(LV_PALETTE_RED));

    /*Copy the previous LED and switch it ON*/
    lv_obj_t * led3  = lv_led_create(lv_screen_active());
    lv_obj_align(led3, LV_ALIGN_CENTER, 80, 0);
    lv_led_on(led3);
}

#endif

API

lv_types.h

lv_led.h