【自学Flutter】3.1 图片的使用

3.1 图片的使用

1.源代码

import 'package:flutter/material.dart';

void main () => runApp(MyApp());

class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context ){
    return MaterialApp(
      title:'All Widget Usages',
      home:Scaffold(
          body:
          Center(
            child:
            Column(
              children: <Widget>[
                Image(
                  image: AssetImage("images/1.jpg"),
                  width: 100.0,
                  height: 100.0,
                ),
                Image.asset("images/1.jpg",
                  width: 100.0,
                  height: 100.0,
                ),
                Image(
                  image: NetworkImage("https://img.ivsky.com/img/tupian/t/201411/27/weixiao_de_ningmeng_3d_sheji.jpg"),
                  width: 100.0,
                  height: 100.0,
                ),
                Image.network("https://img.ivsky.com/img/tupian/t/201411/27/weixiao_de_ningmeng_3d_sheji.jpg",
                  width: 100.0,
                  height: 100.0,
                )
              ],
            )
          )
      ),
    );
  }
}

2.创建文件夹images（将图片丢进去）

3.pubspec.yaml（添加下方代码）

name: flutter_alluse
description: A new Flutter application.

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.2

dev_dependencies:
  flutter_test:
    sdk: flutter


# For information on the generic Dart part of this file, see the
# following page: https://www.dartlang.org/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #  - images/a_dot_burr.jpeg
  #  - images/a_dot_ham.jpeg
  
  # 添加如下代码
  assets:
    - images/1.jpg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages

  fonts:
    - family: AguafinaScript
      fonts:
        - asset: fonts/AguafinaScript-Regular.ttf

4.解释源代码

import 'package:flutter/material.dart';

void main () => runApp(MyApp());

class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context ){
    return MaterialApp(
      title:'All Widget Usages',
      home:Scaffold(
          body:
          Center(
            child:
            Column(
              children: <Widget>[
              	//Asset第一种方式
                Image(
                  image: AssetImage("images/1.jpg"),
                  width: 100.0,
                  height: 100.0,
                ),
                //Asset第二种方式
                Image.asset("images/1.jpg",
                  width: 100.0,
                  height: 100.0,
                ),
                //Network第一种方式
                Image(
                  image: NetworkImage("https://img.ivsky.com/img/tupian/t/201411/27/weixiao_de_ningmeng_3d_sheji.jpg"),
                  width: 100.0,
                  height: 100.0,
                ),
                //Network第二种方式
                Image.network("https://img.ivsky.com/img/tupian/t/201411/27/weixiao_de_ningmeng_3d_sheji.jpg",
                  width: 100.0,
                  height: 100.0,
                )
              ],
            )
          )
      ),
    );
  }
}

4.效果图