1 继续关系:
BoxDecoration:实现边框、圆角、阴影、形状、渐变、背景图像
ShapeDecoration:实现四个边分别指定颜色和宽度、底部线、矩形边色、圆形边色、体育场(竖向椭圆)、 角形(八边角)边色
FlutterLogoDecoration:实现Flutter图片
UnderlineTabindicator:下划线
2 介绍
一个背景装饰对象,相当于Android中的shape.xml,定制各种各样的背景(边框、圆角、阴影、形状、渐变、背景图像)。
3 BoxDecoration例子:
构造方法:
const BoxDecoration({ this.color, // 底色 this.image, // 图片 this.border, 边色 this.borderRadius, // 圆角度 this.boxShadow, // 阴影 this.gradient, // 渐变 this.backgroundBlendMode, // 混合Mode this.shape = BoxShape.rectangle, // 形状 })
3.1 边框+圆角:
decoration: new BoxDecoration( border: new Border.all(color: Color(0xFFFF0000), width: 0.5), // 边色与边宽度 color: Color(0xFF9E9E9E), // 底色 // borderRadius: new BorderRadius.circular((20.0)), // 圆角度 borderRadius: new BorderRadius.vertical(top: Radius.elliptical(20, 50)), // 也可控件一边圆角大小),
3.2 阴影:
decoration: new BoxDecoration( border: new Border.all(color: Color(0xFFFF0000), width: 0.5), // 边色与边宽度// 生成俩层阴影,一层绿,一层黄, 阴影位置由offset决定,阴影模糊层度由blurRadius大小决定(大就更透明更扩散),阴影模糊大小由spreadRadius决定 boxShadow: [BoxShadow(color: Color(0x99FFFF00), offset: Offset(5.0, 5.0), blurRadius: 10.0, spreadRadius: 2.0), BoxShadow(color: Color(0x9900FF00), offset: Offset(1.0, 1.0)), BoxShadow(color: Color(0xFF0000FF))],),
3.3 形状(圆形与矩形):
decoration: new BoxDecoration( border: new Border.all(color: Color(0xFFFFFF00), width: 0.5), // 边色与边宽度 color: Color(0xFF9E9E9E), // 底色 // shape: BoxShape.circle, // 圆形,使用圆形时不可以使用borderRadius shape: BoxShape.rectangle, // 默认值也是矩形 borderRadius: new BorderRadius.circular((20.0)), // 圆角度),
3.4 渐变(环形、扫描式、线性):
decoration: new BoxDecoration( border: new Border.all(color: Color(0xFFFFFF00), width: 0.5), // 边色与边宽度// 环形渲染 gradient: RadialGradient(colors: [Color(0xFFFFFF00), Color(0xFF00FF00), Color(0xFF00FFFF)],radius: 1, tileMode: TileMode.mirror)//扫描式渐变// gradient: SweepGradient(colors: [Color(0xFFFFFF00), Color(0xFF00FF00), Color(0xFF00FFFF)], startAngle: 0.0, endAngle: 1*3.14)// 线性渐变// gradient: LinearGradient(colors: [Color(0xFFFFFF00), Color(0xFF00FF00), Color(0xFF00FFFF)], begin: FractionalOffset(1, 0), end: FractionalOffset(0, 1))),
3.4 背景图像:
decoration: new BoxDecoration( border: new Border.all(color: Color(0xFFFFFF00), width: 0.5), // 边色与边宽度 image: new DecorationImage( image: new NetworkImage('https://avatar.csdn.net/8/9/A/3_chenlove1.jpg'), // 网络图片 // image: new AssetImage('graphics/background.png'), 本地图片 fit: BoxFit.fill // 填满 // centerSlice: new Rect.fromLTRB(270.0, 180.0, 1360.0, 730.0),// 固定大小 ),),
4 ShapeDecoration例子:
构造方法:
const ShapeDecoration({ this.color, this.image, this.gradient, this.shadows, @required this.shape,})
除了shape,其他与BoxDecoration一致,shape研究:
decoration: new ShapeDecoration( color: Color(0xFFFF00FF), // 底色 // 统一四边颜色和宽度 shape: Border.all(color: Color(0xFF00FFFF),style: BorderStyle.solid,width: 2)// 四个边分别指定颜色和宽度, 当只给bottom时与UnderlineInputBorder一致效果// shape: Border(top: b, bottom: b, right: b, left: b)// 底部线// shape: UnderlineInputBorder( borderSide:BorderSide(color: Color(0xFFFFFFFF), style: BorderStyle.solid, width: 2))// 矩形边色// shape: RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(10)), side: BorderSide(color: Color(0xFFFFFFFF), style: BorderStyle.solid, width: 2))// 圆形边色// shape: CircleBorder(side: BorderSide(color: Color(0xFFFFFF00), style: BorderStyle.solid, width: 2))// 体育场(竖向椭圆)// shape: StadiumBorder(side: BorderSide(width: 2, style: BorderStyle.solid, color: Color(0xFF00FFFF))// 角形(八边角)边色// shape: BeveledRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(10)), side: BorderSide(color: Color(0xFFFFFFFF), style: BorderStyle.solid, width: 2))),
5 FlutterLogoDecoration例子:
构造方法:
const FlutterLogoDecoration({ this.lightColor = const Color(0xFF42A5F5), // Colors.blue[400] this.darkColor = const Color(0xFF0D47A1), // Colors.blue[900] this.textColor = const Color(0xFF616161), this.style = FlutterLogoStyle.markOnly, this.margin = EdgeInsets.zero,})
这个就不解析了,Flutter的logo,开发没啥用!
6 UnderlineTabindicator例子:
构造方法:
const UnderlineTabIndicator({ this.borderSide = const BorderSide(width: 2.0, color: Colors.white), this.insets = EdgeInsets.zero,})
这个比较简单就是加下划线,可以设置Insets值(控制下划高底,左右边距)
decoration: new UnderlineTabIndicator( borderSide: BorderSide(width: 2.0, color: Colors.white), insets: EdgeInsets.fromLTRB(0,0,0,10)