如何在Flutter中添加图像 [英] How to add image in Flutter

问题描述

我第一次开发Flutter应用程序。我在添加图像时遇到问题。我有以下问题：

I am developing Flutter app for the first time.. I have an issue in adding a image. I have a below questions :

1. 在哪里创建图片文件夹？


2. 在哪里添加资产标签在pubspec.ymal中？


3. 为此是否需要任何资产文件夹？

我尝试过的操作：

 assets:
    - images/lake.jpg

在pubspec.ymal内部：

inside pubspec.ymal :

完整文件：

name: my_flutter_app
description: A new Flutter application.

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^0.1.2

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:
  uses-material-design: true,
  assets:
    - images/lake.jpg

错误日志：

#/properties/flutter/properties/uses-material-design: type: wanted [boolean] got true,
Error detected in pubspec.yaml:
Error building assets

FAILURE: Build failed with an exception.

* Where:
Script '/home/abc/Downloads/flutter/packages/flutter_tools/gradle/flutter.gradle' line: 435

* What went wrong:
Execution failed for task ':app:flutterBuildDebug'.
> Process 'command '/home/abc/Downloads/flutter/bin/flutter'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s
Finished with error: Gradle build failed: 1

我的main.dart代码：

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';
// Uncomment lines 7 and 10 to view the visual layout at runtime.
//import 'package:flutter/rendering.dart' show debugPaintSizeEnabled;

void main() {
  //debugPaintSizeEnabled = true;
  runApp(new MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    Widget titleSection = new Container(
      padding: const EdgeInsets.all(32.0),
      child: new Row(
        children: [
          new Expanded(
            child: new Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                new Container(
                  padding: const EdgeInsets.only(bottom: 8.0),
                  child: new Text(
                    'Oeschinen Lake Campground',
                    style: new TextStyle(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
                new Text(
                  'Kandersteg, Switzerland',
                  style: new TextStyle(
                    color: Colors.grey[500],
                  ),
                ),
              ],
            ),
          ),
          new Icon(
            Icons.star,
            color: Colors.red[500],
          ),
          new Text('41'),
        ],
      ),
    );

    Column buildButtonColumn(IconData icon, String label) {
      Color color = Theme.of(context).primaryColor;

      return new Column(
        mainAxisSize: MainAxisSize.min,
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          new Icon(icon, color: color),
          new Container(
            margin: const EdgeInsets.only(top: 8.0),
            child: new Text(
              label,
              style: new TextStyle(
                fontSize: 12.0,
                fontWeight: FontWeight.w400,
                color: color,
              ),
            ),
          ),
        ],
      );
    }

    Widget buttonSection = new Container(
      child: new Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: [
          buildButtonColumn(Icons.call, 'CALL'),
          buildButtonColumn(Icons.near_me, 'ROUTE'),
          buildButtonColumn(Icons.share, 'SHARE'),
        ],
      ),
    );

    Widget textSection = new Container(
      padding: const EdgeInsets.all(32.0),
      child: new Text(
        '''
Lake Oeschinen lies at the foot of the Blüemlisalp in the Bernese Alps. Situated 1,578 meters above sea level, it is one of the larger Alpine Lakes. A gondola ride from Kandersteg, followed by a half-hour walk through pastures and pine forest, leads you to the lake, which warms to 20 degrees Celsius in the summer. Activities enjoyed here include rowing, and riding the summer toboggan run.
        ''',
        softWrap: true,
      ),
    );

    return new MaterialApp(
      title: 'Flutter Demo',
      home: new Scaffold(
        appBar: new AppBar(
          title: new Text('Top Lakes'),
        ),
        body: new ListView(
          children: [
            new Image.asset(
              'images/lake.jpg',
              width: 600.0,
              height: 240.0,
              fit: BoxFit.cover,
            ),
            titleSection,
            buttonSection,
            textSection,
          ],
        ),
      ),
    );
  }
}

我指的是本教程 https://flutter.io/tutorials/layout/

I am referring this tutorial https://flutter.io/tutorials/layout/

我也想问一问，有什么工具可以在flutter中进行干净的重建，因为我找不到任何选择。.

Also I want ask that is there any tools for clean rebuild in flutter as i can't find any options for this..

任何帮助都会会感激。

谢谢！

推荐答案

我认为错误是由冗余，

flutter:
  uses-material-design: true, # <<< redundant , at the end of the line
  assets:
    - images/lake.jpg

我还建议在包含 pubspec.yaml 文件的目录中创建一个资产文件夹，并将图片移动到那里并使用

I'd also suggest to create an assets folder in the directory that contains the pubspec.yaml file and move images there and use

flutter:
  uses-material-design: true
  assets:
    - assets/images/lake.jpg

资产目录将获得一些其他的IDE支持，如果您将资产放在其他位置，则将无法获得。

The assets directory will get some additional IDE support that you won't have if you put assets somewhere else.

这篇关于如何在Flutter中添加图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！