一 概述

本文介绍Flutter中的开关控件：

• Switch：只有开关功能，打开/关系开关
• SwitchListTile：带有文字描述和开关的开关控件
• CupertinoSwitch：IOS风格的开关控件

二 Switch-只有开关

2.1 构造方法

const Switch({
    Key? key,
    required this.value,
    required this.onChanged,
    this.activeColor,
    this.activeTrackColor,
    this.inactiveThumbColor,
    this.inactiveTrackColor,
    this.activeThumbImage,
    this.onActiveThumbImageError,
    this.inactiveThumbImage,
    this.onInactiveThumbImageError,
    this.thumbColor,
    this.trackColor,
    this.materialTapTargetSize,
    this.dragStartBehavior = DragStartBehavior.start,
    this.mouseCursor,
    this.focusColor,
    this.hoverColor,
    this.overlayColor,
    this.splashRadius,
    this.focusNode,
    this.autofocus = false,
  })

2.2 常用属性

属性	说明	取值
value	开关是否打开	bool对象
activeTrackColor	滑块轨迹颜色	Colors对象
activeColor	滑块打开后颜色(为图像时，不显示)	Colors对象
inactiveTrackColor	滑块未打开时轨迹颜色	Colors对象
inactiveThumbColor	滑块未打开时颜色	Colors对象
activeThumbImage	滑块打开后的图标	ImageProvider对象

2.3 示例

代码

var _switchValue = false;
Switch(
         activeThumbImage: AssetImage('images/bird.png',),
         inactiveThumbColor: Colors.green,
         inactiveTrackColor: Colors.orange,
         activeColor: Colors.red,
         activeTrackColor: Colors.blue,
         value: _switchValue,
         onChanged: (value) {
                 setState(() {
                   _switchValue = value;
                   });
       })

效果图

三 SwitchListTile-开关+文字

3.1 构造方法

 const SwitchListTile({
    Key? key,
    required this.value,
    required this.onChanged,
    this.tileColor,
    this.activeColor,
    this.activeTrackColor,
    this.inactiveThumbColor,
    this.inactiveTrackColor,
    this.activeThumbImage,
    this.inactiveThumbImage,
    this.title,
    this.subtitle,
    this.isThreeLine = false,
    this.dense,
    this.contentPadding,
    this.secondary,
    this.selected = false,
    this.autofocus = false,
    this.controlAffinity = ListTileControlAffinity.platform,
    this.shape,
    this.selectedTileColor,
  })

3.2 常用属性

属性	说明	取值
value	开关是否打开	bool对象
activeTrackColor	滑块轨迹颜色	Colors对象
activeColor	滑块打开后颜色(为图像时，不显示)	Colors对象
inactiveTrackColor	滑块未打开时轨迹颜色	Colors对象
inactiveThumbColor	滑块未打开时颜色	Colors对象
activeThumbImage	滑块打开后的图标	ImageProvider对象
title	标题	Widget
subtitle	子标题	Widget

3.3 示例

代码

var _switchListValue = false;
SwitchListTile(
                title: Text("开启消息推送？"),
                subtitle: Text("subTitle"),
                 value: _switchListValue,
                 onChanged: (value) {
                    setState(() {
                      _switchListValue = value;
                    });
                 })

效果图

四 CupertinoSwitch-仿IOS

4.1 构造方法

const CupertinoSwitch({
    Key? key,
    required this.value,
    required this.onChanged,
    this.activeColor,
    this.trackColor,
    this.dragStartBehavior = DragStartBehavior.start,
  })

4.2 示例

 var _switchValue = false;
 CupertinoSwitch(
                  value: _switchValue,
                  onChanged: (value) {
                    setState(() {
                      _switchValue = value;
                    });
                  })

效果图