Python类的定义和使用详情
2026/10/10 19:24:39
概念
一个多功能容器,可以设置背景、边距、大小、装饰等
核心属性
child Widget? 容器内的子组件 width double? 容器宽度 height double? 容器高度 color Color? 背景色 padding EdgeInsetsGeometry? 内边距(内容到边框) margin EdgeInsetsGeometry? 外边距(容器到外部) decoration BoxDecoration? 装饰(圆角、阴影、渐变等) alignment AlignmentGeometry? 子组件对齐方式 constraints BoxConstraints? 额外约束限制 transform Matrix4? 变换(旋转、缩放) clipBehavior Clip? 裁剪行为基本用法
Container( width:100, //宽 height: 100,//高 //外边距:有三个参数all(全部),only(单边),symmetric(水平或垂直), margin: EdgeInsets.symmetric(horizontal: 8), padding: EdgeInsets.all(8),//内边距的用法和外边距一样 alignment: Alignment(0, 0),//对齐方式 decoration: BoxDecoration( //颜色,withOpacity是用来设置透明度的,值的范围(0.0~1.0) color: Color(0xFF5091C9).withOpacity(0.3), //圆角效果 borderRadius: BorderRadius.circular(20), //边框 border: Border.all(color: Colors.black,width: 5), boxShadow: [ // 阴影 BoxShadow( color: Colors.black26, //颜色 blurRadius: 8, //模糊程度 offset: Offset(2, 2),//偏移 spreadRadius:2,//扩散范围 ), ], //设置形状 // shape: BoxShape.circle, //形状和圆角不能同时设置 ), child: Text( "内容" ), )不同方式的圆角
// 不同角的圆角 Container( decoration: BoxDecoration( color: Colors.blue, borderRadius: BorderRadius.only( topLeft: Radius.circular(20), topRight: Radius.circular(10), bottomLeft: Radius.circular(5), bottomRight: Radius.circular(15), ), ), child: Text('四个角不同圆角'), )线性渐变LinearGradient
// 线性渐变 Container( width: 200, height: 100, decoration: BoxDecoration( gradient: LinearGradient( begin: Alignment.topLeft, end: Alignment.bottomRight, colors: [ Colors.blue, Colors.purple, ], ), borderRadius: BorderRadius.circular(12), ), child: Center(child: Text('渐变色', style: TextStyle(color: Colors.white))), )径向渐变(从中心向外)RadialGradient
// 径向渐变(从中心向外) Container( decoration: BoxDecoration( gradient: RadialGradient( center: Alignment.center, radius: 0.8, colors: [ Colors.yellow, Colors.orange, Colors.red, ], ), ), child: Text('径向渐变'), )设置图片背景
Container( width: 200, height: 150, decoration: BoxDecoration( image: DecorationImage( image: AssetImage('assets/images/background.png'), fit: BoxFit.cover, // 覆盖 ), borderRadius: BorderRadius.circular(12), ), child: Center( child: Text( '背景图', style: TextStyle(color: Colors.white, fontSize: 20), ), ), )对齐方式
Container( width: 200, height: 200, color: Colors.grey[200], alignment: Alignment.center, // 居中 child: Container( width: 50, height: 50, color: Colors.blue, ), ) // 常用的对齐常量 alignment: Alignment.topLeft // 左上 alignment: Alignment.topCenter // 上中 alignment: Alignment.topRight // 右上 alignment: Alignment.centerLeft // 左中 alignment: Alignment.center // 正中心(默认) alignment: Alignment.centerRight // 右中 alignment: Alignment.bottomLeft // 左下 alignment: Alignment.bottomCenter // 下中 alignment: Alignment.bottomRight // 右下自定义偏移
// 坐标范围:-1.0 ~ 1.0 Container( alignment: Alignment(-0.5, 0.3), // 左偏50%,下偏30% child: Container(width: 50, height: 50, color: Colors.blue), )约束控制
Container( constraints: BoxConstraints( minWidth: 100, maxWidth: 300, minHeight: 50, maxHeight: 150, ), color: Colors.blue, child: Text('尺寸限制'), )