Flutter 图片、圆形头像、圆角图片....各种形状

图片

1. 本地图片

 Image.asset 加载项目资源包的图片 

//先将图片拷贝到项目 images 目录中，然后在 pubspec.yaml文件配置文件相对路径到 assets 
Image.asset(
  'images/cat.jpg',
   200,
  height: 200,
)

 Image.file 加载手机内置或外置存储的图片

//加载Android平台的外置存储图片需要AndroidManifest.xml配置android.permission.READ_EXTERNAL_STORAGE权限
Image.file(
  File('/0/images/cat.jpg'),
   200,
  height: 200,
)

2. 网络图片

 Image.network 无本地缓存

Image.network(
  'https://pic4.zhimg.com/v2-19dced236bdff0c47a6b7ac23ad1fbc3.jpg',
   200,
  height: 200,
)

 FadeInImage.assetNetwork  淡入效果，无本地缓存

FadeInImage.assetNetwork(
  placeholder: 'images/avatar.png',
  image: 'https://pic1.zhimg.com/v2-7fab628481a26f025188b095b5cfafbc.jpg',
   200,
  height: 200
)

 CachedNetworkImage  第三方控件，有本地缓存和淡入效果

//1、将依赖框架配置到pubspec.yaml文件
dependencies:
  cached_network_image: ^0.7.0

//2、引入相关类
import 'package:cached_network_image/cached_network_image.dart';

//3、使用控件，默认自带图片淡入效果
CachedNetworkImage(
  imageUrl: 'https://pic4.zhimg.com/v2-19dced236bdff0c47a6b7ac23ad1fbc3.jpg',
   200,
  height: 200,
)

---

圆形头像

方式1: CircleAvatar

CircleAvatar(
  //头像半径
  radius: 60,
  //头像图片 -> NetworkImage网络图片，AssetImage项目资源包图片, FileImage本地存储图片
  backgroundImage: NetworkImage(
    'https://pic2.zhimg.com/v2-639b49f2f6578eabddc458b84eb3c6a1.jpg'
  ),
)

方式2: ClipOval

ClipOval(
  child: Image.network(
    'https://pic2.zhimg.com/v2-639b49f2f6578eabddc458b84eb3c6a1.jpg',
     120,
    height: 120,
    fit: BoxFit.cover,
  ),
)

方式3:  Container + BoxDecoration

Container(
   120,
  height: 120,
  decoration: BoxDecoration(
    shape: BoxShape.circle,
    image: DecorationImage(
      image: NetworkImage('https://pic2.zhimg.com/v2-639b49f2f6578eabddc458b84eb3c6a1.jpg'),
      fit: BoxFit.cover
    )
  )
)

---

圆角图片

方式1: ClipRRect

ClipRRect(
  borderRadius: BorderRadius.circular(8),
  child: Image.network(
    'https://pic2.zhimg.com/v2-639b49f2f6578eabddc458b84eb3c6a1.jpg',
     120,
    height: 120
  )
)

方式2: Container + BoxDecoration 

Container(
   120,
  height: 120,
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(8),
    image: DecorationImage(
      image: NetworkImage('https://pic2.zhimg.com/v2-639b49f2f6578eabddc458b84eb3c6a1.jpg')
    )
  )
)

---

各种形状

使用ShapeDecoration可以做出各种形状

• 斜切角: BeveledRectangleBorder
• 圆角: RoundedRectangleBorder
• 超椭圆: SuperellipseShape
• 体育场: StadiumBorder
• 圆形: CircleBorder

//斜切角形状示例
Container(
   120,
  height: 120,
  decoration: ShapeDecoration(
    shape: BeveledRectangleBorder(
      borderRadius: BorderRadius.circular(16)
    ),
    image: DecorationImage(
      fit: BoxFit.cover,
      image: NetworkImage('https://pic2.zhimg.com/v2-639b49f2f6578eabddc458b84eb3c6a1.jpg')
    )
  )
)