flutter之从零搭建小米商城APP（三）首页的搭建

小鱼儿 2023-06-28 04:54 21阅读 0赞

#### 1.公共组件HeaderNav ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70]  
下面是**HeaderNav.dart**

import 'package:flutter/material.dart';
    
    class HeaderNav extends StatefulWidget { 
      final Container left;
      final Container right;
      final Container content; //接受三个从父组件的传递过来的值，分别是left ，content，right，代表左，中，右
      HeaderNav({ Key key, this.left, this.content, this.right}) : super(key: key);
      @override
      createState() => new HeaderComponent();
    }
    
    class HeaderComponent extends State<HeaderNav> { 
      @override
      Widget build(BuildContext context) { 
        return Container(
          decoration: new BoxDecoration(color: Color(0xfff2f2f2)),
          height: 40,
          padding: EdgeInsets.fromLTRB(0, 5, 0, 5),
          child: Row(
            children: <Widget>[
              Expanded(
                child: widget.left,
                flex: 1,
              ),
              Expanded(child: widget.content, flex: 6),
              Expanded(
                child: widget.right,
                flex: 1,
              )
            ],
          ),
        );
      }
    }

#### 2.home.dart ####

import 'package:flutter/material.dart';
    import 'package:mi_shop/components/HeaderNav.dart';
    import 'package:mi_shop/http/index.dart';
    import 'package:mi_shop/http/api.dart';
    import 'package:mi_shop/components/Nav.dart';
    
    class Home extends StatefulWidget { 
      @override
      State<StatefulWidget> createState() { 
        return new Page();
      }
    }
    
    class Page extends State<Home> { 
      @override
      Widget build(BuildContext context) { 
        return layout(context);
      }
    
      Widget layout(BuildContext context) { 
        return new MaterialApp(
          home: new Scaffold(
              // appBar: new AppBar(
              // title: new Text('Welcome to Home'),
              // ),
              body: new Container(
            child: new Column(
              children: <Widget>[
                new HeaderNav(
                    left: Container(
                      child: Image(
                        image: new AssetImage('images/logo.png'),
                        height: 15,
                      ),
                    ),
                    content: Container(
                      decoration: new BoxDecoration(
                          border:
                              new Border.all(width: 1, color: Color(0xffe5e5e5)),
                          borderRadius: BorderRadius.all(Radius.circular(2.0))),
                      child: Scaffold(
                        body: Row(
                          children: <Widget>[
                            Container(
                              child: Icon(Icons.search,
                                  color: Color(0x4D000000), size: 20),
                              margin: EdgeInsets.fromLTRB(5, 0, 3, 0),
                            ),
                            Expanded(
                              child: new TextField(
                                decoration: new InputDecoration(
                                  hintText: '搜索商品名称',
                                  hintStyle: new TextStyle(
                                      fontSize: 13.0, color: Color(0x4D000000)),
                                  fillColor: Colors.white, // 背景颜色
                                  filled: true, // 支持背景颜色
                                  contentPadding:
                                      const EdgeInsets.symmetric(vertical: 4),
                                  border: OutlineInputBorder(
                                      borderSide: BorderSide.none,
                                      // borderSide: BorderSide(color: Color(0xffe5e5e5)),
                                      borderRadius: BorderRadius.circular(3)),
                                ),
                              ),
                            ),
                          ],
                        ),
                      ),
                    ),
                    right: Container(
                      child: Image(
                        image: new AssetImage('images/user.png'),
                        height: 18,
                      ),
                    )),
              ],
            ),
          )),
        );
      }
    }

#### 3.成果 ####

下方框中即为实现效果，left对应mi的图标，content对应中间输入框，right对应人的logo  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70 1]

#### 4.注意的点 ####

1）首先引入本地图片，在根目录下创建文件夹images，然后再根目录下的pubspec.yaml下引入，截图都写出，然后按上面代码写的直接引入就行，两步缺一不可  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70 2]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70 3]  
2）其次本想使用TextField 的prefixIcon来实现再输入框前缀图标，但发现这个prefixIcon的padding设置只能为正数，所以设置就没用，然后图标与搜字隔了很远，因为他这个有默认值，改变不了，真的鸡肋，但是我真的骂了一小时，找了很多文档，才找到同道说改不了，垃圾！就只有用一个容器包含一个图标，一个输入框，才解决，心累，先写这么多，后续完善。  
![在这里插入图片描述][20200107150806838.png]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200107145841701.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200107150303898.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200107150448923.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20200107150521498.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3l1YW5xaTMxMzE=,size_16,color_FFFFFF,t_70
[20200107150806838.png]: https://img-blog.csdnimg.cn/20200107150806838.png