Flutter中的不同屏幕尺寸和dpi缩放

时间:2019-06-06 19:21:33

标签: android flutter size screen

  @override
  Widget build(BuildContext context) {

    final double shortesSide = MediaQuery.of(context).size.shortestSide;
    final bool useMobileLayout = shortesSide <= 600.0; //use this for mobile
    final Orientation orientation = MediaQuery.of(context).orientation;

    return Scaffold(
      resizeToAvoidBottomPadding: false,
      backgroundColor: Color.fromRGBO(246, 246, 246, 1.0),
      appBar: AppBar(
          backgroundColor: Color.fromRGBO(121, 85, 72, 1.0),
          centerTitle: true,
          title: Text(...),
          leading: IconButton(
            onPressed: () {
              Navigator.pushReplacementNamed(context, 'Menu');
            },
            icon: Icon(
              Icons.arrow_back,
              color: Colors.white,
            ),
          )),
      body: useMobileLayout
          ? _buildPhoneView(orientation: orientation)
          : _buildTabletView(orientation: orientation),
    );
  }



//phone
  Container _buildPhoneView({@required Orientation orientation}) {...}

//tablet
  Container _buildTabletView({@required Orientation orientation}) {...}

诸如600以下的平板电脑的小型手机是否有突破口?我是否需要构建第三个布局,还是可以仅根据屏幕大小校正文本和小部件。谢谢

2 个答案:

答案 0 :(得分:1)

这取决于您要构建的布局的复杂性。例如,对于复杂的布局,当屏幕尺寸变小时,小部件可能会覆盖其他小部件,或者当它们没有空间时可能会出现像素溢出。即使Flutter在不同的屏幕上都能很好地缩放,有时候这还不够。

我正在使用LayoutBuilder小部件,并根据其框约束,返回适合其当前约束的屏幕布局。

*请注意,LayoutBuilder小部件从其父级获取约束,因此请确保将其作为顶部小部件放置。

def find(my_list, value):

    index = 0
    k = -1 

    for element in my_list:
        if element != value :
            index += 1

        if element == value:
            k = index
    return k

}

答案 1 :(得分:1)

您可以使用此插件flutter_screenutil。 这是一个用于调整屏幕和字体大小的flutter插件。让您的UI在不同的屏幕大小上显示合理的布局!

根据系统的“字体大小”可访问性选项初始化并设置合适的大小和字体大小以进行缩放 请在使用前设置设计图稿的宽度和高度,以及设计图稿的宽度和高度(单位px)。确保将页面设置在MaterialApp的主页中(即,输入文件,只需设置一次),以确保在每次使用之前设置合适的尺寸:

//fill in the screen size of the device in the design

//default value : width : 1080px , height:1920px , 
allowFontScaling:false
ScreenUtil.instance = ScreenUtil.getInstance()..init(context);

//If the design is based on the size of the iPhone6 ​​(iPhone6 ​​750*1334)
ScreenUtil.instance = ScreenUtil(width: 750, height: 
1334)..init(context);

//If you wang to set the font size is scaled according to the system's 
"font size" assist option
ScreenUtil.instance = ScreenUtil(width: 750, height: 1334, 
allowFontScaling: true)..init(context);

使用:# 适应屏幕尺寸: 传递设计草图的px大小:

适应屏幕宽度:ScreenUtil.getInstance()。setWidth(540),

适应屏幕高度:ScreenUtil.getInstance()。setHeight(200),

您还可以使用ScreenUtil()代替ScreenUtil.getInstance(),例如:ScreenUtil()。setHeight(200)

注意

高度也根据setWidth进行调整,以确保不变形(当您想要一个正方形时)

setHeight方法主要在高度上进行调整,您希望在显示相同的UIUsed时控制屏幕的高度和真实性。

//for example:
//rectangle
Container(
       width: ScreenUtil.getInstance().setWidth(375),
       height: ScreenUtil.getInstance().setHeight(200),
       ...
        ),

////If you want to display a square:
Container(
       width: ScreenUtil.getInstance().setWidth(300),
       height: ScreenUtil.getInstance().setWidth(300),
        ),

适配器字体:

//Incoming font size,the unit is pixel, fonts will not scale to 
respect Text Size accessibility settings
//(AllowallowFontScaling when initializing ScreenUtil)
ScreenUtil.getInstance().setSp(28)    

//Incoming font size,the unit is pixel,fonts will scale to respect Text 
Size accessibility settings
//(If somewhere does not follow the global allowFontScaling setting)
ScreenUtil(allowFontScaling: true).setSp(28)  

//for example:

Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Text(
                'My font size is 24px on the design draft and will not change with the system.',
                style: TextStyle(
                  color: Colors.black,
                  fontSize: ScreenUtil.getInstance().setSp(24),
                )),
            Text(
                'My font size is 24px on the design draft and will change with the system.',
                style: TextStyle(
                  color: Colors.black,
                  fontSize: ScreenUtil(allowFontScaling: true).setSp(24),
                )),
          ],
        )

其他相关API:

ScreenUtil.pixelRatio       //Device pixel density
ScreenUtil.screenWidth      //Device width
ScreenUtil.screenHeight     //Device height
ScreenUtil.bottomBarHeight  //Bottom safe zone distance, suitable for buttons with full screen
ScreenUtil.statusBarHeight  //Status bar height , Notch will be higher Unit px
ScreenUtil.textScaleFactory //System font scaling factor

ScreenUtil.getInstance().scaleWidth //Ratio of actual width dp to design draft px
ScreenUtil.getInstance().scaleHeight //Ratio of actual height dp to design draft px