1. 添加图片资源

# 添加某个资源图片
flutter:
  assets:
    - assets/my_icon.png
    - assets/app/background.png

# 添加文件夹下的所有资源图片
flutter:
  assets:
    - assets/
    - assets/app/

2. 如何使用

Image(
  image: AssetImage('assets/app/background.png'),
)

3.设置图片大小

Image(
  image: AssetImage('assets/app/background.png'),
  width: 200.0,
  height: 200.0
)

Image(
  image: AssetImage('assets/app/background.png'),
  width: 200.0,
  fit: BoxFit.fitWidth
)