Flutter how to create responsive Text widget?

Question

I'm facing a problem with responsive texts. In my app are different text font sizes and I need to do them responsive for different screen sizes (only phones and device orientation portrait). I also added textScaleFactor: 1.0 to my MaterialApp like this:

    builder: (context, widget) {
      return MediaQuery(
        child: widget,
        data: MediaQuery.of(context).copyWith(textScaleFactor: 1.0),
      );
    },

but it does not helped much. I tried also calculate the font size with MediaQuery.of(context).size.width, but I think it dangerous and wrong. I want it to be as close as possible to the design that was given to me, but I started to lose it on this steps. Is there any solution for this? How you achieve this?

Thank you in advance.

Answer 1

you can use this plugin flutter_screenutil. It is a flutter plugin for adapting screen and font size.Let your UI display a reasonable layout on different screen sizes!

Initialize and set the fit size and font size to scale according to the system's "font size" accessibility option # Please set the width and height of the design draft before use, the width and height of the design draft (unit px). Be sure to set the page in the MaterialApp's home(ie the entry file, just set it once) to ensure that the fit size is set before each use:

//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);

Use： # Adapt screen size： # Pass the px size of the design draft：

Adapted to screen width: ScreenUtil.getInstance().setWidth(540),

Adapted to screen height: ScreenUtil.getInstance().setHeight(200),

You can also use ScreenUtil() instead of ScreenUtil.getInstance(), for example:ScreenUtil().setHeight(200)

Note

Height is also adapted according to setWidth to ensure no deformation (when you want a square)

setHeight method is mainly adapted in height, you want to control the height and actuality of a screen on the UIUsed when the same is displayed.

//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),
        ),

Adapter font:

//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),
                )),
          ],
        )

Other related apis：

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