如何在 Flutter 中裁剪图像? [英] How do I crop an image in Flutter?

问题描述

假设我有一个矩形的纵向图像:

我想裁剪它，使其呈现如下:

我如何在 Flutter 中做到这一点?

(我不需要调整图像大小.)

(图片来自

import 'package:flutter/material.dart';无效主(){运行应用程序(新材料应用程序(主页:新的我的主页()，));}class MyHomePage 扩展了 StatelessWidget {小部件构建(BuildContext 上下文){返回新的脚手架(应用栏:新的应用栏(标题:新文本(图像裁剪示例")，),身体:新中心(孩子:新的纵横比(纵横比:487/451，孩子:新容器(装饰:新的 BoxDecoration(图像:新的装饰图像(适合:BoxFit.fitWidth，对齐:FractionalOffset.topCenter，图片:new NetworkImage('https://i.stack.imgur.com/lkd0a.png'),)),),),),);}}

Let's say I have a rectangular, portrait image:

I'd like to crop it, such that it's rendered like this:

How can I do this in Flutter?

(I don't need to resize the image.)

(Image from https://flic.kr/p/nwXTDb)

解决方案

I would probably use a BoxDecoration with a DecorationImage. You can use the alignment and fit properties to determine how your image is cropped. You can use an AspectRatio widget if you don't want to hard code a height on the Container.

import 'package:flutter/material.dart';

void main() {
  runApp(new MaterialApp(
    home: new MyHomePage(),
  ));
}

class MyHomePage extends StatelessWidget {

  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("Image Crop Example"),
      ),
      body: new Center(
        child: new AspectRatio(
          aspectRatio: 487 / 451,
          child: new Container(
            decoration: new BoxDecoration(
              image: new DecorationImage(
                fit: BoxFit.fitWidth,
                alignment: FractionalOffset.topCenter,
                image: new NetworkImage('https://i.stack.imgur.com/lkd0a.png'),
              )
            ),
          ),
        ),
      ),
    );
  }
}

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