列表 (lv_list)

概述

列表基本上是一个带有垂直布局的矩形，可以向其中添加按钮和文本。

部件和样式

背景

• LV_PART_MAIN 列表的主要部分，使用所有典型的背景属性。

• LV_PART_SCROLLBAR 滚动条。有关详细信息，请参阅 基础对象 的文档。

按钮和文本 请参阅 按钮 和 标签 的文档。

用法

按钮

lv_list_add_btn(list, icon, text) 添加一个带有图标（可以是图像或符号）和文本的全宽按钮。

如果文本太长，将开始水平滚动。

文本

lv_list_add_text(list, text) 添加一段文本。

事件

列表不发送特殊事件，但按钮会像往常一样发送事件。

了解更多关于事件的信息。

按键

列表对象不处理任何按键。

了解更多关于按键的信息。

示例

Simple List

C code  

 GitHub

#include "../../lv_examples.h"
#if LV_USE_LIST && LV_BUILD_EXAMPLES
static lv_obj_t * list1;

static void event_handler(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    lv_obj_t * obj = lv_event_get_target(e);
    if(code == LV_EVENT_CLICKED) {
        LV_LOG_USER("Clicked: %s", lv_list_get_btn_text(list1, obj));
    }
}

void lv_example_list_1(void)
{
    /*Create a list*/
    list1 = lv_list_create(lv_scr_act());
    lv_obj_set_size(list1, 180, 220);
    lv_obj_center(list1);

    /*Add buttons to the list*/
    lv_obj_t * btn;

    lv_list_add_text(list1, "File");
    btn = lv_list_add_btn(list1, LV_SYMBOL_FILE, "New");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_DIRECTORY, "Open");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_SAVE, "Save");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_CLOSE, "Delete");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_EDIT, "Edit");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);

    lv_list_add_text(list1, "Connectivity");
    btn = lv_list_add_btn(list1, LV_SYMBOL_BLUETOOTH, "Bluetooth");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_GPS, "Navigation");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_USB, "USB");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_BATTERY_FULL, "Battery");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);

    lv_list_add_text(list1, "Exit");
    btn = lv_list_add_btn(list1, LV_SYMBOL_OK, "Apply");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
    btn = lv_list_add_btn(list1, LV_SYMBOL_CLOSE, "Close");
    lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);
}

#endif

MicroPython code  

 GitHub Simulator

def event_handler(e):
    code = e.get_code()
    obj = e.get_target()
    if code == lv.EVENT.CLICKED:
            print("Clicked: list1." + list1.get_btn_text(obj))

# Create a list
list1 = lv.list(lv.scr_act())
list1.set_size(180, 220)
list1.center()

# Add buttons to the list
list1.add_text("File")
btn_new = list1.add_btn(lv.SYMBOL.FILE, "New")
btn_new.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_open = list1.add_btn(lv.SYMBOL.DIRECTORY, "Open")
btn_open.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_save = list1.add_btn(lv.SYMBOL.SAVE, "Save")
btn_save.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_delete = list1.add_btn(lv.SYMBOL.CLOSE, "Delete")
btn_delete.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_edit = list1.add_btn(lv.SYMBOL.EDIT, "Edit")
btn_edit.add_event_cb(event_handler,lv.EVENT.ALL, None)

list1.add_text("Connectivity")
btn_bluetooth = list1.add_btn(lv.SYMBOL.BLUETOOTH, "Bluetooth")
btn_bluetooth.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_navig = list1.add_btn(lv.SYMBOL.GPS, "Navigation")
btn_navig.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_USB = list1.add_btn(lv.SYMBOL.USB, "USB")
btn_USB.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_battery = list1.add_btn(lv.SYMBOL.BATTERY_FULL, "Battery")
btn_battery.add_event_cb(event_handler,lv.EVENT.ALL, None)

list1.add_text("Exit")
btn_apply = list1.add_btn(lv.SYMBOL.OK, "Apply")
btn_apply.add_event_cb(event_handler,lv.EVENT.ALL, None)
btn_close = list1.add_btn(lv.SYMBOL.CLOSE, "Close")
btn_close.add_event_cb(event_handler,lv.EVENT.ALL, None)

---

Sorting a List using up and down buttons

C code  

 GitHub

#include <stdlib.h>


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

static lv_obj_t * list1;
static lv_obj_t * list2;

static lv_obj_t * currentButton = NULL;

static void event_handler(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    lv_obj_t * obj = lv_event_get_target(e);
    if(code == LV_EVENT_CLICKED) {
        LV_LOG_USER("Clicked: %s", lv_list_get_btn_text(list1, obj));

        if(currentButton == obj) {
            currentButton = NULL;
        }
        else {
            currentButton = obj;
        }
        lv_obj_t * parent = lv_obj_get_parent(obj);
        uint32_t i;
        for(i = 0; i < lv_obj_get_child_cnt(parent); i++) {
            lv_obj_t * child = lv_obj_get_child(parent, i);
            if(child == currentButton) {
                lv_obj_add_state(child, LV_STATE_CHECKED);
            }
            else {
                lv_obj_clear_state(child, LV_STATE_CHECKED);
            }
        }
    }
}

static void event_handler_top(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    if(code == LV_EVENT_CLICKED) {
        if(currentButton == NULL) return;
        lv_obj_move_background(currentButton);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_up(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    if((code == LV_EVENT_CLICKED) || (code == LV_EVENT_LONG_PRESSED_REPEAT)) {
        if(currentButton == NULL) return;
        uint32_t index = lv_obj_get_index(currentButton);
        if(index <= 0) return;
        lv_obj_move_to_index(currentButton, index - 1);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_center(lv_event_t * e)
{
    const lv_event_code_t code = lv_event_get_code(e);
    if((code == LV_EVENT_CLICKED) || (code == LV_EVENT_LONG_PRESSED_REPEAT)) {
        if(currentButton == NULL) return;

        lv_obj_t * parent = lv_obj_get_parent(currentButton);
        const uint32_t pos = lv_obj_get_child_cnt(parent) / 2;

        lv_obj_move_to_index(currentButton, pos);

        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_dn(lv_event_t * e)
{
    const lv_event_code_t code = lv_event_get_code(e);
    if((code == LV_EVENT_CLICKED) || (code == LV_EVENT_LONG_PRESSED_REPEAT)) {
        if(currentButton == NULL) return;
        const uint32_t index = lv_obj_get_index(currentButton);

        lv_obj_move_to_index(currentButton, index + 1);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_bottom(lv_event_t * e)
{
    const lv_event_code_t code = lv_event_get_code(e);
    if(code == LV_EVENT_CLICKED) {
        if(currentButton == NULL) return;
        lv_obj_move_foreground(currentButton);
        lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
    }
}

static void event_handler_swap(lv_event_t * e)
{
    const lv_event_code_t code = lv_event_get_code(e);
    // lv_obj_t* obj = lv_event_get_target(e);
    if((code == LV_EVENT_CLICKED) || (code == LV_EVENT_LONG_PRESSED_REPEAT)) {
        uint32_t cnt = lv_obj_get_child_cnt(list1);
        for(int i = 0; i < 100; i++)
            if(cnt > 1) {
                lv_obj_t * obj = lv_obj_get_child(list1, rand() % cnt);
                lv_obj_move_to_index(obj, rand() % cnt);
                if(currentButton != NULL) {
                    lv_obj_scroll_to_view(currentButton, LV_ANIM_ON);
                }
            }
    }
}

void lv_example_list_2(void)
{
    /*Create a list*/
    list1 = lv_list_create(lv_scr_act());
    lv_obj_set_size(list1, lv_pct(60), lv_pct(100));
    lv_obj_set_style_pad_row(list1, 5, 0);

    /*Add buttons to the list*/
    lv_obj_t * btn;
    int i;
    for(i = 0; i < 15; i++) {
        btn = lv_btn_create(list1);
        lv_obj_set_width(btn, lv_pct(50));
        lv_obj_add_event_cb(btn, event_handler, LV_EVENT_CLICKED, NULL);

        lv_obj_t * lab = lv_label_create(btn);
        lv_label_set_text_fmt(lab, "Item %d", i);
    }

    /*Select the first button by default*/
    currentButton = lv_obj_get_child(list1, 0);
    lv_obj_add_state(currentButton, LV_STATE_CHECKED);

    /*Create a second list with up and down buttons*/
    list2 = lv_list_create(lv_scr_act());
    lv_obj_set_size(list2, lv_pct(40), lv_pct(100));
    lv_obj_align(list2, LV_ALIGN_TOP_RIGHT, 0, 0);
    lv_obj_set_flex_flow(list2, LV_FLEX_FLOW_COLUMN);

    btn = lv_list_add_btn(list2, NULL, "Top");
    lv_obj_add_event_cb(btn, event_handler_top, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, LV_SYMBOL_UP, "Up");
    lv_obj_add_event_cb(btn, event_handler_up, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, LV_SYMBOL_LEFT, "Center");
    lv_obj_add_event_cb(btn, event_handler_center, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, LV_SYMBOL_DOWN, "Down");
    lv_obj_add_event_cb(btn, event_handler_dn, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, NULL, "Bottom");
    lv_obj_add_event_cb(btn, event_handler_bottom, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);

    btn = lv_list_add_btn(list2, LV_SYMBOL_SHUFFLE, "Shuffle");
    lv_obj_add_event_cb(btn, event_handler_swap, LV_EVENT_ALL, NULL);
    lv_group_remove_obj(btn);
}

#endif

MicroPython code  

 GitHub Simulator

import urandom

currentButton = None
list1 = None

def event_handler(evt):
    global currentButton
    code = evt.get_code()
    obj = evt.get_target()
    if code == lv.EVENT.CLICKED:
        if currentButton == obj:
            currentButton = None
        else:
            currentButton = obj
        parent = obj.get_parent()
        for i in range( parent.get_child_cnt()):
            child = parent.get_child(i)
            if child == currentButton:
                child.add_state(lv.STATE.CHECKED)
            else:
                child.clear_state(lv.STATE.CHECKED)

def event_handler_top(evt):
    global currentButton
    code = evt.get_code()
    obj = evt.get_target()
    if code == lv.EVENT.CLICKED:
        if currentButton == None:
            return
        currentButton.move_background()
        currentButton.scroll_to_view( lv.ANIM.ON)

def event_handler_up(evt):
    global currentButton
    code = evt.get_code()
    obj = evt.get_target()
    if code == lv.EVENT.CLICKED or code == lv.EVENT.LONG_PRESSED_REPEAT:
        if currentButton == None:
            return
        index = currentButton.get_index()
        if index <= 0:
            return
        currentButton.move_to_index(index - 1)
        currentButton.scroll_to_view(lv.ANIM.ON)

def event_handler_center(evt):
    global currentButton
    code = evt.get_code()
    obj = evt.get_target()
    if code == lv.EVENT.CLICKED or code == lv.EVENT.LONG_PRESSED_REPEAT:
        if currentButton == None:
            return
        parent = currentButton.get_parent()
        pos = parent.get_child_cnt() // 2
        currentButton.move_to_index(pos)
        currentButton.scroll_to_view(lv.ANIM.ON)

def event_handler_dn(evt):
    global currentButton
    code = evt.get_code()
    obj = evt.get_target()
    if code == lv.EVENT.CLICKED or code == lv.EVENT.LONG_PRESSED_REPEAT:
        if currentButton == None:
            return
        index = currentButton.get_index()
        currentButton.move_to_index(index + 1)
        currentButton.scroll_to_view(lv.ANIM.ON)

def event_handler_bottom(evt):
    global currentButton
    code = evt.get_code()
    obj = evt.get_target()
    if code == lv.EVENT.CLICKED or code == lv.EVENT.LONG_PRESSED_REPEAT:
        if currentButton == None:
            return
        currentButton.move_foreground()
        currentButton.scroll_to_view(lv.ANIM.ON)

def event_handler_swap(evt):
    global currentButton
    global list1
    code = evt.get_code()
    obj = evt.get_target()
    if code == lv.EVENT.CLICKED:
        cnt = list1.get_child_cnt()
        for i in range(100):
            if cnt > 1:
                obj = list1.get_child(urandom.getrandbits(32) % cnt )
                obj.move_to_index(urandom.getrandbits(32) % cnt)
        if currentButton != None:
            currentButton.scroll_to_view(lv.ANIM.ON)

#Create a list with buttons that can be sorted
list1 = lv.list(lv.scr_act())
list1.set_size(lv.pct(60), lv.pct(100))
list1.set_style_pad_row( 5, 0)

for i in range(15):
    btn = lv.btn(list1)
    btn.set_width(lv.pct(100))
    btn.add_event_cb( event_handler, lv.EVENT.CLICKED, None)
    lab = lv.label(btn)
    lab.set_text("Item " + str(i))

#Select the first button by default
currentButton = list1.get_child(0)
currentButton.add_state(lv.STATE.CHECKED)

#Create a second list with up and down buttons
list2 = lv.list(lv.scr_act())
list2.set_size(lv.pct(40), lv.pct(100))
list2.align(lv.ALIGN.TOP_RIGHT, 0, 0)
list2.set_flex_flow(lv.FLEX_FLOW.COLUMN)

btn = list2.add_btn(None, "Top")
btn.add_event_cb(event_handler_top, lv.EVENT.ALL, None)
lv.group_remove_obj(btn)

btn = list2.add_btn(lv.SYMBOL.UP, "Up")
btn.add_event_cb(event_handler_up, lv.EVENT.ALL, None)
lv.group_remove_obj(btn)

btn = list2.add_btn(lv.SYMBOL.LEFT, "Center")
btn.add_event_cb(event_handler_center, lv.EVENT.ALL, None)
lv.group_remove_obj(btn)

btn = list2.add_btn(lv.SYMBOL.DOWN, "Down")
btn.add_event_cb(event_handler_dn, lv.EVENT.ALL, None)
lv.group_remove_obj(btn)

btn = list2.add_btn(None, "Bottom")
btn.add_event_cb(event_handler_bottom, lv.EVENT.ALL, None)
lv.group_remove_obj(btn)

btn = list2.add_btn(lv.SYMBOL.SHUFFLE, "Shuffle")
btn.add_event_cb(event_handler_swap, lv.EVENT.ALL, None)
lv.group_remove_obj(btn)

---

API

Functions

lv_obj_t *lv_list_create(lv_obj_t *parent)

lv_obj_t *lv_list_add_text(lv_obj_t *list, const char *txt)

lv_obj_t *lv_list_add_btn(lv_obj_t *list, const void *icon, const char *txt)

const char *lv_list_get_btn_text(lv_obj_t *list, lv_obj_t *btn)

Variables

const lv_obj_class_t lv_list_class

const lv_obj_class_t lv_list_text_class

const lv_obj_class_t lv_list_btn_class