Flutter set background image for a page - flutter

I want to set the image as the background color for the page but the code below seems not to work well. I'm not sure if there is something missing in my code or mistake inside. And there is no error message shown.
class LoginPage extends StatefulWidget {
#override
_LoginPageState createState() => _LoginPageState();
}
class _LoginPageState extends State<LoginPage> {
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.tealAccent,
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/background.png"),
fit: BoxFit.cover,
),
),
child: Center(
child: Column(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
SizedBox(height: 50),
_signInButton(),
],
),
),
),
);
}

you have to just use stack widget just like this
Stack(
children: <Widget>[
Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/login.png"), fit: BoxFit.fill)),
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
child: <YOUR CHILD COMPONENTS WILL BE PLACED HERE>
),
],
),
Hope it will help!

Related

Flutter - Problem about Transform with Network Image and Expanded Text

I'm trying to create a simple Container includes;
A text aligned to center left (that text can include 50 characters)
A network image which is aligned to bottom right, rotated a bit, and rounded.
I've written a code like this:
import 'package:flutter/material.dart';
class MyScreen extends StatefulWidget {
static const String idScreen = "myScreen";
#override
_MyScreenState createState() => _MyScreenState();
}
class _MyScreenState extends State<MyScreen> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("My Screen")),
body: Column(
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
width: MediaQuery.of(context).size.width,
height: 100,
alignment: Alignment.bottomRight,
decoration: BoxDecoration(
shape: BoxShape.rectangle,
borderRadius: BorderRadiusDirectional.circular(16.0),
color: Colors.yellow),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
"Baby",
style: TextStyle(
fontSize: 25,
fontWeight: FontWeight.bold,
),
),
),
Transform(
child: Image.network(
"https://target.scene7.com/is/image/Target/Baby-210913-1631564062108?wid=315&hei=315&qlt=60&fmt=png",
fit: BoxFit.contain,
),
transform: Matrix4.rotationZ(-0.2),
alignment: FractionalOffset.centerRight,
),
],
),
),
),
],
),
);
}
}
But the output is:
In order to avoid white square in image, I tried to add my picture in Transform like:
Container(
width: 50,
height: 50,
decoration: const BoxDecoration(
shape: BoxShape.circle,
image: DecorationImage(
fit: BoxFit.contain,
image: NetworkImage(
"https://target.scene7.com/is/image/Target/Baby-210913-1631564062108?wid=315&hei=315&qlt=60&fmt=png"
)
)
)
But flutter doesn't accept it in Transform widget. How can I solve this?
Also another problem; if I write "Baby" like "Baby Baby Baby Baby Baby Baby Baby Baby ", it gives overflow error. I tried to wrap my Text or Row with Expanded but didn't work. How can I solve this too?

Why does MainAxisAlignment of a Column have different outputs in flutter?

I used mainAxisAlignment: MainAxisAlignment.end, in my "Column" to place some content on the bottom of the screen. This works fine.
I needed to add a picture, this picture was also shown at the bottom of the screen, align and positioned didn't change it. So I put the Column as a child in another column, this allows me, to put the picture in a row, and place it in the right top corner. But now the content of the original column is centered in the screen. What should I do?
Should look like this:
Here my code:
Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/Images/backgroundhomescreen.png'),
fit: BoxFit.cover,
),
),
child:Column(
children: [
Row( //Logo
children: [
Image(
image: AssetImage('assets/Images/logo.png'),
width: 120,
),
]
),
Column(
//crossAxisAlignment: CrossAxisAlignment.center,
// mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[...
You can either set the crossAxisAlignment to CrossAxisAlignment.end to align all the children to the right or wrap the TopBox widget in Align.
class MyWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Container( //Outer Container
height: 900,
width: 400,
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
),
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: [
// Align(
// alignment: Alignment.centerRight,
// child: TopBox()
// ,),
TopBox(),
Spacer(),
BottomBox(),
],
),
);
}
}
class BottomBox extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Container(
color: Colors.blue,
height: 200,
);
}
}
class TopBox extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Container(
margin: EdgeInsets.all(15),
color: Colors.blue,
height: 100,
width: 175,
);
}
}
You could simply achieve custom spacing in flutter using the spacer widget

flutter dot indicator to pageview

I want to add a dot indicator to pageview. When a person scrolls the image to the right to left image changes on my code. NO problem with there but I couldn't manage to add a dot indicator to my code. How can I put a dot indicator when I scroll across images also the dots switch to the order of images.........................................................................................................
PageView.builder(
itemCount: totalCards.toInt(),
itemBuilder: (context, i) {
return Container(
margin: EdgeInsets.only(top: 10),
child: Container(
child: Column(
mainAxisAlignment:
MainAxisAlignment.spaceBetween,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Expanded(
child: PageView(
children: <Widget>[
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(4.0),
image: DecorationImage(
image: AssetImage(
photos[startphoto]),
fit: BoxFit.cover)),
),
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(4.0),
image: DecorationImage(
image: AssetImage(
photos[startphoto1]),
fit: BoxFit.cover)),
),
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(4.0),
image: DecorationImage(
image: AssetImage(
photos[startphoto2]),
fit: BoxFit.fitHeight)),
),
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.circular(4.0),
image: DecorationImage(
image: AssetImage(
photos[startphoto3]),
fit: BoxFit.cover)),
),
],
),
),
],
),
)
);
},
),
),
You can do that with this package: https://pub.dev/packages/page_view_indicators
In the example you can see how to implement it.
EDIT: Implement your dot indicator like this:
class HomeScreen extends StatefulWidget {
#override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
final ValueNotifier<int> _pageNotifier = new ValueNotifier<int>(0);
final PageController _pageController = new PageController();
#override
Widget build(BuildContext context) {
return Column(
children: [
PageView.builder(
itemCount: totalCards.toInt(),
controller: _pageController,
itemBuilder: (context, i) {
...
},
onPageChanged:(index) {
setState(() {
_pageNotifier.value = index;
});
},
),
Center(
child: CirclePageIndicator(
currentPageNotifier: _pageNotifier,
itemCount: totalCards.toInt(),
),
)
],
);
}
}

Flutter: Background becomes half after putting logo image

So I am trying to put my image logo on the background, but my background suddenly became cropped with half of a black screen appearing. As per picture:
My main.dart code:
import 'package:flutter/material.dart';
import 'login_page.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
home: new LoginPage(),
theme: new ThemeData(
primarySwatch: Colors.green
)
);
}
}
my login_page.dart code:
import 'package:flutter/material.dart';
class LoginPage extends StatefulWidget{
#override
State createState() => new LoginPageState();
}
class LoginPageState extends State<LoginPage>{
#override
Widget build(BuildContext context){
return new Scaffold(
backgroundColor: Colors.transparent,
body: new Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Image.asset('assets/arrowPNG.png'),
]
),
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/background.png"),
fit: BoxFit.cover,
)
)
)
);
}
}
It happened after putting the image logo which is 'Image.asset('assets/arrowPNG.png'),'. How do I resolve this?
Try this below code
class LoginPageState extends State<LoginPage>{
#override
Widget build(BuildContext context){
return new Scaffold(
backgroundColor: Colors.transparent,
body: new Container(
width: MediaQuery.of(context).size.width,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Image.asset('images/a_dot_ham.png'),
]
),
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("images/background.jpg"),
fit: BoxFit.cover,
)
)
)
);
}
When you add the below line to your Container, the issue will get resolved
width: MediaQuery.of(context).size.width
Here is my result
Try to add, width: MediaQuery.of(context).size.width height: MediaQuery.of(context).size.height to Container like this,
Container(
width: MediaQuery.of(context).size.width,
height: MediaQuery.of(context).size.height,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Image.asset('assets/images/logo.png'),
]
),
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/splash_bg.png"),
fit: BoxFit.cover,
)
)
)
Output

How do I Set Background image in Flutter?

I am trying to set a background image for the home page. I am getting the image place from start of the screen and filling the width but not the height.
Am I missing something in my code? Are there image standards for flutter? Do images scale based on each phone's screen resolution?
class BaseLayout extends StatelessWidget{
#override
Widget build(BuildContext context){
return Scaffold(
body: Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Image.asset("assets/images/bulb.jpg")
]
)
)
);
}
}
I'm not sure I understand your question, but if you want the image to fill the entire screen you can use a DecorationImage with a fit of BoxFit.cover.
class BaseLayout extends StatelessWidget{
#override
Widget build(BuildContext context){
return Scaffold(
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/bulb.jpg"),
fit: BoxFit.cover,
),
),
child: null /* add child content here */,
),
);
}
}
For your second question, here is a link to the documentation on how to embed resolution-dependent asset images into your app.
If you use a Container as the body of the Scaffold, its size will be accordingly the size of its child, and usually that is not what you want when you try to add a background image to your app.
Looking at this other question, #collin-jackson was also suggesting to use Stack instead of Container as the body of the Scaffold and it definitely does what you want to achieve.
This is how my code looks like
#override
Widget build(BuildContext context) {
return new Scaffold(
body: new Stack(
children: <Widget>[
new Container(
decoration: new BoxDecoration(
image: new DecorationImage(image: new AssetImage("images/background.jpg"), fit: BoxFit.cover,),
),
),
new Center(
child: new Text("Hello background"),
)
],
)
);
}
Screenshot:
Code:
#override
Widget build(BuildContext context) {
return DecoratedBox(
decoration: BoxDecoration(
image: DecorationImage(image: AssetImage("your_asset"), fit: BoxFit.cover),
),
child: Center(child: FlutterLogo(size: 300)),
);
}
You can use Stack to make the image stretch to the full screen.
Stack(
children: <Widget>
[
Positioned.fill( //
child: Image(
image: AssetImage('assets/placeholder.png'),
fit : BoxFit.fill,
),
),
...... // other children widgets of Stack
..........
.............
]
);
Note: Optionally if are using a Scaffold, you can put the Stack inside the Scaffold with or without AppBar according to your needs.
I was able to apply a background below the Scaffold (and even it's AppBar) by putting the Scaffold under a Stack and setting a Container in the first "layer" with the background image set and fit: BoxFit.cover property.
Both the Scaffold and AppBar has to have the backgroundColor set as Color.transparent and the elevation of AppBar has to be 0 (zero).
Voilà! Now you have a nice background below the whole Scaffold and AppBar! :)
import 'package:flutter/material.dart';
import 'package:mynamespace/ui/shared/colors.dart';
import 'package:mynamespace/ui/shared/textstyle.dart';
import 'package:mynamespace/ui/shared/ui_helpers.dart';
import 'package:mynamespace/ui/widgets/custom_text_form_field_widget.dart';
class SignUpView extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Stack( // <-- STACK AS THE SCAFFOLD PARENT
children: [
Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/bg.png"), // <-- BACKGROUND IMAGE
fit: BoxFit.cover,
),
),
),
Scaffold(
backgroundColor: Colors.transparent, // <-- SCAFFOLD WITH TRANSPARENT BG
appBar: AppBar(
title: Text('NEW USER'),
backgroundColor: Colors.transparent, // <-- APPBAR WITH TRANSPARENT BG
elevation: 0, // <-- ELEVATION ZEROED
),
body: Padding(
padding: EdgeInsets.all(spaceXS),
child: Column(
children: [
CustomTextFormFieldWidget(labelText: 'Email', hintText: 'Type your Email'),
UIHelper.verticalSpaceSM,
SizedBox(
width: double.maxFinite,
child: RaisedButton(
color: regularCyan,
child: Text('Finish Registration', style: TextStyle(color: white)),
onPressed: () => {},
),
),
],
),
),
),
],
);
}
}
We can use Container and mark its height as infinity
body: Container(
height: double.infinity,
width: double.infinity,
child: FittedBox(
fit: BoxFit.cover,
child: Image.network(
'https://cdn.pixabay.com/photo/2016/10/02/22/17/red-t-shirt-1710578_1280.jpg',
),
),
));
Output:
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('images/background.png'),fit:BoxFit.cover
)
),
);
decoration: BoxDecoration(
image: DecorationImage(
image: ExactAssetImage("images/background.png"),
fit: BoxFit.cover
),
),
this also works inside a container.
Other answers are great. This is another way it can be done.
Here I use SizedBox.expand() to fill available space and for passing tight constraints for its children (Container).
BoxFit.cover enum to Zoom the image and cover whole screen
Widget build(BuildContext context) {
return Scaffold(
body: SizedBox.expand( // -> 01
child: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: NetworkImage('https://flutter.github.io/assets-for-api-docs/assets/widgets/owl-2.jpg'),
fit: BoxFit.cover, // -> 02
),
),
),
),
);
}
To set a background image without shrinking after adding the child, use this code.
body: Container(
constraints: BoxConstraints.expand(),
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/aaa.jpg"),
fit: BoxFit.cover,
)
),
//You can use any widget
child: Column(
children: <Widget>[],
),
),
You can use the following code to set a background image to your app:
class HomePage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("images/background.jpg"),
fit: BoxFit.cover,
),
),
// use any child here
child: null
),
);
}
If your Container's child is a Column widget, you can use the crossAxisAlignment: CrossAxisAlignment.stretch to make your background image fill the screen.
I know there is a lot of answers to this question already, but this solution comes with a color gradient around the background image, I think you would like it
import 'package:flutter/material.dart';
class BackgroundImageExample extends StatelessWidget {
const BackgroundImageExample({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Stack(
children: [
backgroudImage(),
Scaffold(
backgroundColor: Colors.transparent,
body: SafeArea(
child: Column(
children: [
// your body content here
],
),
),
),
],
);
}
Widget backgroudImage() {
return ShaderMask(
shaderCallback: (bounds) => LinearGradient(
colors: [Colors.black, Colors.black12],
begin: Alignment.bottomCenter,
end: Alignment.center,
).createShader(bounds),
blendMode: BlendMode.darken,
child: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('your image here'), /// change this to your image directory
fit: BoxFit.cover,
colorFilter: ColorFilter.mode(Colors.black45, BlendMode.darken),
),
),
),
);
}
}
Stack(
children: [
SizedBox.expand(
child: FittedBox(
fit: BoxFit.cover,
child: Image.asset(
Images.splashBackground,
),
)
),
your widgets
])
This Helped me
import 'package:flutter/material.dart';
void main() => runApp(DestiniApp());
class DestiniApp extends StatefulWidget {
#override
_DestiniAppState createState() => _DestiniAppState();
}
class _DestiniAppState extends State<DestiniApp> {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: SafeArea(
child: Scaffold(
appBar: AppBar(
backgroundColor: Color.fromRGBO(245, 0, 87, 1),
title: Text(
"Landing Page Bankground Image",
),
),
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: ExactAssetImage("images/appBack.jpg"),
fit: BoxFit.cover
),
),
),
),
),
);
}
}
Output:
#override
Widget build(BuildContext context) {
return Scaffold(
body: SingleChildScrollView(
child: Container(
decoration: const BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/bgmain.jpg'),
//fit: BoxFit.cover
fit: BoxFit.fill),
),
child: Column(
children:
[
//
],
),
)));
}
Image.asset(
"assets/images/background.png",
fit: BoxFit.cover,
height: double.infinity,
width: double.infinity,
alignment: Alignment.center,
),
if still there is a problèm, it' seem like your image is not perfection in the heigth and width
Here is how you can achieve this. First example is with assets image and the second one is with network image.
Local image:
Container(
height: 200,
width: double.infinity,
decoration: const BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/cat2.jpg"),
fit: BoxFit.cover),
),
child:
)
Network image:
Container(
height: 200,
width: double.infinity,
decoration: const BoxDecoration(
image: DecorationImage(
image: NetworkImage("https://picsum.photos/id/237/200/300"),
fit: BoxFit.cover),
),
child:
)
You can use FractionallySizedBox
Sometimes decoratedBox doesn't cover the full-screen size.
We can fix it by wrapping it with FractionallySizedBox Widget.
In this widget we give widthfactor and heightfactor.
The widthfactor shows the [FractionallySizedBox]widget should take _____ percentage of the app's width.
The heightfactor shows the [FractionallySizedBox]widget should take _____ percentage of the app's height.
Example : heightfactor = 0.3 means 30% of app's height. widthfactor = 0.4 means 40% of app's width.
Hence, for full screen set heightfactor = 1.0 and widthfactor = 1.0
Tip: FractionallySizedBox goes well with the stack widget. So that you can easily add buttons, avatars, texts over your background image in the stack widget whereas in rows and columns you cannot do that.
For more info check out this project's repository github repository link for this project
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: SafeArea(
child: Stack(
children: <Widget>[
Container(
child: FractionallySizedBox(
heightFactor: 1.0,
widthFactor: 1.0,
//for full screen set heightFactor: 1.0,widthFactor: 1.0,
child: DecoratedBox(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("images/1.jpg"),
fit: BoxFit.fill,
),
),
),
),
),
],
),
),
),
);
}
}
OutPut:
It can be done either of the following ways, based on your requirement:
Background image spanning accross the app Bar
Scaffold(
extendBodyBehindAppBar: true,
appBar: AppBar(
elevation: 0,
title: const Text(
"Home Page",
style: TextStyle(color: Colors.white),
),
backgroundColor: Colors.transparent,
),
body: Container(
height: double.infinity,
width: double.infinity,
decoration: const BoxDecoration(
image: DecorationImage(
fit: BoxFit.fill,
image: NetworkImage(
'https://wallpaperaccess.com/full/2440003.jpg'))
child: < Your Widgets go here >
),
));
Background image not spanning accross the app Bar
Scaffold(
appBar: AppBar(
elevation: 0,
title: const Text(
"Home Page",
style: TextStyle(color: Colors.black),
),
backgroundColor: Colors.transparent,
),
body: Container(
height: double.infinity,
width: double.infinity,
decoration: const BoxDecoration(
image: DecorationImage(
fit: BoxFit.fill,
image: NetworkImage(
'https://wallpaperaccess.com/full/2440003.jpg'))
child: < Your Widgets go here >
),
));
Extra :
To add background image only to the appBar refer this answer