无法构建center和text小部件

如何解决无法构建center和text小部件

我正在开发新应用。在创建登录页面时，我遇到了一些问题。我的代码可以正常工作到一个点，在该点或线之后，它将停止构建更多的小部件。

我的代码（工作部分）：

void main() => runApp(
  MaterialApp(
    debugShowCheckedModeBanner:false,home: Background1(),),);


class Background1 extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Scaffold( //Whole screen
          body: Container(
              padding: EdgeInsets.all(20),width: double.infinity,decoration: BoxDecoration(
                gradient: LinearGradient(
                  begin: Alignment.topCenter,colors: [
                    Colors.purple.shade700,Colors.purple.shade500,Colors.purple.shade300,],child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,children: <Widget>[
                SizedBox (height: 80),Padding(
                  padding: EdgeInsets.all(20),child: Column(
                    children: <Widget>[
                      Text("LOGIN",style: TextStyle(color: Colors.white,fontSize: 40,fontWeight: FontWeight.bold)),Expanded(
                  child: Container(
                    decoration: BoxDecoration(
                      borderRadius: BorderRadius.only(topLeft: Radius.circular(20),topRight: Radius.circular(20),bottomLeft: Radius.circular(20),bottomRight: Radius.circular(20)),color: Colors.transparent,child: Padding(
                      padding: EdgeInsets.all(20),child: Column(
                        children: <Widget>[
                          SizedBox(
                            height: 20,Container(
                            padding: EdgeInsets.all(10),decoration: BoxDecoration(
                              color: Colors.white,borderRadius: BorderRadius.circular(20),boxShadow: [BoxShadow(
                                color: Color.fromRGBO(225,95,27,0.3),blurRadius: 20,offset: Offset(0,10),)],child: Column(
                              children: <Widget>[
                                Container(
                                  padding: EdgeInsets.all(10),decoration: BoxDecoration(
                                    border: Border(bottom: BorderSide(color: Colors.grey[200])),child: TextField(
                                    decoration: InputDecoration(
                                      hintText: "Email or phone number",hintStyle: TextStyle(color: Colors.grey),border: InputBorder.none,SizedBox(height: 10),Container(
                                  padding: EdgeInsets.all(10),child: TextField(
                                    decoration: InputDecoration(
                                      hintText: "Password",SizedBox(height: 40),Text("Forgot Password?",style: TextStyle(color: Colors.white)),Container(
                            height: 40,margin: EdgeInsets.symmetric(horizontal: 50),padding: EdgeInsets.all(20),decoration: BoxDecoration(
                              color: Colors.purple.shade800,borderRadius: BorderRadius.circular(20)),child: Center(
                              child: Text("LOGIN",);
  }
}

无法创建位于代码末尾的center（）和Text（）小部件。

child: Text("LOGIN",

当我进一步写时，它也不会构建小部件。我已附上一张图像，显示我的模拟器在紫色按钮上未以白色显示LOGIN的情况。 enter image description here

解决方法

只需除去容器的填充物，它将正常工作。

删除容器填充后的

代码：

void main() => runApp(
      MaterialApp(
        debugShowCheckedModeBanner: false,home: Background1(),),);

class Background1 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Scaffold(
        //Whole screen
        body: Container(
          padding: EdgeInsets.all(20),width: double.infinity,decoration: BoxDecoration(
            gradient: LinearGradient(
              begin: Alignment.topCenter,colors: [
                Colors.purple.shade700,Colors.purple.shade500,Colors.purple.shade300,],child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,children: <Widget>[
              SizedBox(height: 80),Padding(
                padding: EdgeInsets.all(20),child: Column(
                  children: <Widget>[
                    Text("LOGIN",style: TextStyle(
                            color: Colors.white,fontSize: 40,fontWeight: FontWeight.bold)),Expanded(
                child: Container(
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.only(
                        topLeft: Radius.circular(20),topRight: Radius.circular(20),bottomLeft: Radius.circular(20),bottomRight: Radius.circular(20)),color: Colors.transparent,child: Padding(
                    padding: EdgeInsets.all(20),child: Column(
                      children: <Widget>[
                        SizedBox(
                          height: 20,Container(
                          padding: EdgeInsets.all(10),decoration: BoxDecoration(
                            color: Colors.white,borderRadius: BorderRadius.circular(20),boxShadow: [
                              BoxShadow(
                                color: Color.fromRGBO(225,95,27,0.3),blurRadius: 20,offset: Offset(0,10),)
                            ],child: Column(
                            children: <Widget>[
                              Container(
                                padding: EdgeInsets.all(10),decoration: BoxDecoration(
                                  border: Border(
                                      bottom:
                                          BorderSide(color: Colors.grey[200])),child: TextField(
                                  decoration: InputDecoration(
                                    hintText: "Email or phone number",hintStyle: TextStyle(color: Colors.grey),border: InputBorder.none,SizedBox(height: 10),Container(
                                padding: EdgeInsets.all(10),child: TextField(
                                  decoration: InputDecoration(
                                    hintText: "Password",SizedBox(height: 40),Text("Forgot Password?",style: TextStyle(color: Colors.white)),Container(
                          height: 40,margin: EdgeInsets.symmetric(horizontal: 50),decoration: BoxDecoration(
                              color: Colors.purple.shade800,borderRadius: BorderRadius.circular(20)),child: Center(
                            child: Text("LOGIN",style: TextStyle(
                                    color: Colors.white,);
  }
}

,

您可能正在使用屏幕上的所有空间，而不是使用带有列表视图的列，这将允许您滚动。另外，Listview.builder允许您动态构建列表视图的子级。 检出https://api.flutter.dev/flutter/widgets/ListView-class.html以获得有关listview类的信息