Question

经过可能的问题后，我问这个问题。我已经尝试了很多答案。但是没有一个人在为我工作！

SO中的大多数问题都在使用MaterialApp，但我返回的是普通的Material类bcoz，我不想要Actionbar或类似的东西。

我要实现的目标？ 我正在尝试创建一个简单的登录屏幕，其中“应用程序”图标位于顶部，然后“用户名”，“密码”和“登录按钮”紧随该应用程序图标。

但是a！未在AssetImage上加载应用程序图标。

下面是我的代码

class Login extends StatelessWidget{


  @override
  Widget build(BuildContext context) {

    return new Material(

        color: Color.fromARGB(255, 0, 68, 178),
        child: new Container(
          margin: const EdgeInsets.all(5.0),

            child: new Column(
              mainAxisAlignment: MainAxisAlignment.center,

                //This will have Login EditTexts....

                children: <Widget>[

                //Adding Logo on Login Screen....
                //NOT WORKING
                // new DecoratedBox(
                //     decoration: BoxDecoration(
                //       image: DecorationImage(
                //           image: AssetImage("assets/app_logo.jpg")
                //         )
                //     ),
                // ),

                    //NOT WORKING
                // new ImageIcon(
                //   new AssetImage("assests/app_logo.jpg"),
                //   size: 24.0,
                //   color: Colors.white,
                // ),

                    //NOT WORKING
                // new Container(
                //   decoration: new BoxDecoration(
                //     image: new DecorationImage(
                //       colorFilter: new ColorFilter.mode(
                //         Colors.black.withOpacity(0.6),
                //         BlendMode.dstATop
                //       ),
                //       image: new AssetImage("assets/applogo.jpg"),
                //       fit: BoxFit.contain
                //     )
                //   )
                // ),

                    //NOT WORKING
                // new Image.asset(
                //           'assets/applogo.jpg',
                //           height: 60.0,
                //           fit: BoxFit.cover,
                //         ),

                    //NOT WORKING
                new Directionality(
                        textDirection:TextDirection.ltr,
                      child: new Image.asset(
                        "assets/applogo.jpg",
                        height: 100.0,
                        width: 100.0,
                        fit: BoxFit.contain
                        )
                      ),

                  //WORKING
                new Text("Lets Login....", textDirection: TextDirection.ltr),

                  //WORKING
                //Username TextField goes below....
                new Directionality(
                        textDirection: TextDirection.ltr,
                        child: new TextField(
                          decoration: InputDecoration(
                          border: InputBorder.none,
                          hintText: 'Enter Username:'
                        ),
                    )
                ),


                      //WORKING
                //Password TextField goes below......
                new Directionality(
                  textDirection:TextDirection.ltr,
                  child: new TextField(
                    decoration: InputDecoration(
                      border: InputBorder.none,
                      hintText:"Enter Password:"
                    )
                  )
                ),


                      //WORKING
                //Login Button with Inkwell goes below....
                new Directionality(
                    textDirection:TextDirection.ltr,
                    child: new InkWell(
                        child : new RaisedButton(
                          padding: const EdgeInsets.all(8.0),
                          textColor: Colors.white,
                          color: Colors.blue,
                          onPressed: login,
                          child: new Text("Login", textAlign: TextAlign.center, textDirection: TextDirection.ltr)
                        )
                  )
                )



                ],

            ),//child Column closes here...


        ),//Container closes here.....

    );//return Material closes here....

  }//build closes here.....


  void login(){

    print("Login Pressed...");

  }//login closes here....

}//Login class closes here....

下面是我的pubspec.yaml

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

  assets:
      - assets/
      - assets/app_logo.jpg

Answer 1

当您尝试引用图像资产时，代码中存在一些错字，例如“ assets / applogo .jpg”或“ assets /app_logo.jpg”。尝试以下示例：

 Image.asset(
   "assets/app_logo.jpg", 
   height: 60.0, 
   fit: BoxFit.cover
 ),

无法加载资产：资产/在子实体<小部件>中

1 个答案: