Line（线条） (lv_line)¶
Overview（概述）¶
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The Line object is capable of drawing straight lines between a set of points.
线条(Line)组件能在给出的一组点之间绘制出相连的直线。
Parts and Styles（零件和样式）¶
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LV_PART_MAINuses all the typical background properties and line style properties.
LV_PART_MAIN使用所有典型的背景属性和线条样式属性。
Usage（用法）¶
Set points(设置点)¶
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The points have to be stored in an lv_point_t array and passed to the object by the lv_line_set_points(lines, point_array, point_cnt) function.
点必须存储在 lv_point_t 类型的数组中，并通过 lv_line_set_points(lines, point_array, point_cnt) 函数将数组传递给line对象。
Auto-size（自动调整大小）¶
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By default the Line's width and height are set to LV_SIZE_CONTENT. This means it will automatically set its size to fit all the points. If the size is set explicitly, parts on the line may not be visible.
默认情况下，线条的宽度和高度被设置为 LV_SIZE_CONTENT 。也就是它会根据给出的点自动调整其大小来适应所有点的分布。如果你设置了宽、高，那么线条上的有些部分可能会不可见。
Invert y(反转 y轴)¶
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By default, the y == 0 point is in the top of the object. It might be conter-intuitive in some cases so the y coordinates can be inverted with lv_line_set_y_invert(line, true). In this case, y == 0 will be the bottom of the object.
y invert is disabled by default.
默认情况下，y == 0 点是在line对象的顶部最左侧。这在某些情况下可能是不直观的(LCD坐标系)，这时候可以使用 lv_line_set_y_invert(line, true) 函数来反转 y 坐标。在这种情况下，y == 0 将是物体的底部最左侧(直角坐标系)。
默认不反转y轴。
Events（事件）¶
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Only the Generic events are sent by the object type.
See the events of the Base object too.
Learn more about Events.
线条对象仅发送 通用事件。
参见 Base object 的事件。
详细了解 事件。
Example¶
Simple Line¶
C code
GitHub#include "../../lv_examples.h"
#if LV_USE_LINE && LV_BUILD_EXAMPLES
void lv_example_line_1(void)
{
/*Create an array for the points of the line*/
static lv_point_t line_points[] = { {5, 5}, {70, 70}, {120, 10}, {180, 60}, {240, 10} };
/*Create style*/
static lv_style_t style_line;
lv_style_init(&style_line);
lv_style_set_line_width(&style_line, 8);
lv_style_set_line_color(&style_line, lv_palette_main(LV_PALETTE_BLUE));
lv_style_set_line_rounded(&style_line, true);
/*Create a line and apply the new style*/
lv_obj_t * line1;
line1 = lv_line_create(lv_scr_act());
lv_line_set_points(line1, line_points, 5); /*Set the points*/
lv_obj_add_style(line1, &style_line, 0);
lv_obj_center(line1);
}
#endif
# Create an array for the points of the line
line_points = [ {"x":5, "y":5},
{"x":70, "y":70},
{"x":120, "y":10},
{"x":180, "y":60},
{"x":240, "y":10}]
# Create style
style_line = lv.style_t()
style_line.init()
style_line.set_line_width(8)
style_line.set_line_color(lv.palette_main(lv.PALETTE.BLUE))
style_line.set_line_rounded(True)
# Create a line and apply the new style
line1 = lv.line(lv.scr_act())
line1.set_points(line_points, 5) # Set the points
line1.add_style(style_line, 0)
line1.center()
API¶
Functions
-
lv_obj_t *lv_line_create(lv_obj_t *parent)¶
Create a line object
- 参数
parent -- pointer to an object, it will be the parent of the new line
- 返回
pointer to the created line
-
void lv_line_set_points(lv_obj_t *obj, const lv_point_t points[], uint16_t point_num)¶
Set an array of points. The line object will connect these points.
- 参数
obj -- pointer to a line object
points -- an array of points. Only the address is saved, so the array needs to be alive while the line exists
point_num -- number of points in 'point_a'
-
void lv_line_set_y_invert(lv_obj_t *obj, bool en)¶
Enable (or disable) the y coordinate inversion. If enabled then y will be subtracted from the height of the object, therefore the y = 0 coordinate will be on the bottom.
- 参数
obj -- pointer to a line object
en -- true: enable the y inversion, false:disable the y inversion
Variables
-
const lv_obj_class_t lv_line_class¶
-
struct lv_line_t¶