I am new to flutter and I am developing an app in Flutter. While I am doing this, I try to add ElevatedButton which is the latest version of RaisedButton, and its return error and I am also not sure why. I will insert the error code image and would be grateful if someone tells me what is the reason for the error and how to solve it. Thank you
You need to add a child widget (it is required in addition to onPressed function). Here is a sample code for Elevated Button. You can adjust it based on your needs:
ElevatedButton(
style: ElevatedButton.styleFrom(
onPrimary: Colors.white,
primary: Color(0xffccbbd7),
minimumSize: const Size(330,70),
shape: const RoundedRectangleBorder(
borderRadius: BorderRadius.all(
Radius.circular(5),
),
),
),
onPressed: () {},
child: const Text('click'),
),
You Forgot the child Widget inside ElevatedButton, in this button onPressed and child widgets are required
Refer ElevatedButton
Try below code
ElevatedButton(
onPressed: () {
// write your onPressed function here
print('Button Pressed');
},
child: const Text('Press Me'),
),
Your result screen->
Well, elevated button should have child inside. Can be text, icon or image
ElevatedButton(
onPressed: () {
print('Tombol baru saja ditekan!');
},
child: const Text('Hit me!'),
),
Related
What is this black rectangle space that pops on top of the keyboard when clicking on a text form field? The issue only occurs when on an Android device using the web browser. It also seems very inconsistent as you can see on the GIF, sometimes it occurs, sometimes it does not. I could not figure what it is because there were no error logs occurring when doing remote debugging. In the remote debugging, the keyboard displays on the middle(the black thing) and there is some white space on the bottom (see second picture below). Would you know what could be causing this? This app is running on an older version of Flutter by the way which is 2.10.5 so was this a known issue? I've added the Scaffold code below and TextFormField for reference. If someone can point me to the right direction, it would be much appreciated!
This is the code for the main Scaffolding:
return Scaffold(
backgroundColor: Colors.black87,
body: SafeArea(
bottom: false,
child: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage(Images.backgroundImg),
fit: BoxFit.fitHeight)),
child: PageLayout(
header: NotAuthorizedHeader(
isBackPress: false,
),
child: LoginLayout(
onLogin: props.login,
loading: props.isAuthenticating,
authMessageError: props.authMessageError),
getMoreList: () {},
loadingMore: false,
),
),
),
);
Then this is the text form field snippet:
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
placeholder,
style: GoogleFonts.poppins(
fontSize: 14,
fontWeight: FontWeight.w500,
color: AppColors.gray3),
),
const SizedBox(height: 10),
TextFormField(
validator: validator,
onChanged: onChanged,
keyboardType: keyboardType,
obscureText: obscureText,
style: GoogleFonts.poppins(
color: AppColors.gray10,
fontSize: 13,
fontWeight: FontWeight.w400),
decoration: InputDecoration(
filled: true,
fillColor: AppColors.gray9,
hoverColor: AppColors.gray9,
border: OutlineInputBorder(
borderSide: BorderSide.none,
borderRadius: BorderRadius.circular(4),
),
),
onEditingComplete: () {},
onFieldSubmitted: (value) {
onSubmit();
},
)
],
);
I have solved this problem after further testing. Apparently the black rectangle was being caused by the resizeToAvoidBottomInset: true property of the Scaffold on mobile web browsers. So the fix was to set the Scaffold property resizeToAvoidBottomInset: false when the platform is on web.
I'm sorry that I have never see or used an actual device with android OS such as Google pixcel, but I found that gray-out area on top of screen like screen shot below.
*This is "Pixcel 4 API 30 mobile emulator" called from vsCode.
And I found this kind of dead area on Pixcel 5 emulator as well, but am not sure that this is somthing in common for all android OS.
Finally, I'd like to ask that if I should avoid something to display here or this is only emulator matters and do not have to care about this ?
In case that I have to care this area with developing by flutter, should I intentionally separate code or design between these kind of device and the others, as I'm usually using Iphone emulator and actual machine but have never seen this area and beleive I need not to care this kind of area and adopting top-margin for this problem.
Thanks for your helpful comment.
Code Added:
class holder extends ConsumerWidget {
#override
Widget build(BuildContext context, WidgetRef ref) {
ref.watch(_modalProvider );
return Scaffold(
body: Column(
children: [
Container(
margin: const EdgeInsets.only(bottom: 10),
// flex: 1,
child: Container(
margin: EdgeInsets.only(top: 40),//should I do this to avoid this area?
width: double.infinity,
height: 40,
// color: Colors.grey,
alignment: Alignment.topLeft,
child: Image.asset('images/flutter.png'),
),
),
Flexible(
child: ListView(
scrollDirection: Axis.vertical,
shrinkWrap: true,
children: [
Folders(
name: "list",
subTitle: null,
),
],
)
),
],
),
floatingActionButtonLocation: FloatingActionButtonLocation.endTop,
floatingActionButton: Container(
width: 50.0,
child: FloatingActionButton(
backgroundColor: Colors.white,
child: const Icon(
Icons.search_sharp,
color: MyStyle.mainColor,
),
onPressed: () {
ref.read(_modalProvider.notifier).update((state){
showTopModalSheet<String?>(context, DumyModal());
});
},
),
),
);
}
}
That area will be also visible in real devices so you should take that area into consideration. But Scaffold widget will start the rendering from below that point so you don't have to think about it.
İf you want to change color of that area, you can
Container(
decoration: BoxDecoration(color: Color.white),
child: SafeArea(
Scaffold:...
)
)
It also effects IOS and Android devices differently, I believe that is why it is only visible in some devices
I need to implement such a widget in Flutter. Full version of the page, where this widget is going to be used is here Maybe you know build-in widgets, which could help me. But if there are none, what is the best way to implement this widget?
You can use a ListTile
ListTile(
leading: const Text("Lbikgabsb"),
trailing: Column(
children: [
const Text("900 P"),
const Text("2"), // add your decoration to the background
),
],
),
),
Alternatively you can use:
SizedBox(
height: your_height,
width:double.infinity,
child: Row(
children:[
Text("Lbikgabsb"),
Column(
children: [
const Text("900 P"),
const Text("2"), // add your decoration to the background
],
),
),
You can choose whichever approach works best for your app
The problem is that I have a RichText inside a Scrollable Widget(SingleChildScrollView or ListView) and I need to Scroll to a specific TextSpan inside the RichText. Also, I cannot use ScrollablePositionedList because the texts should write in the end of the last one and if there was no space to continue the text should go to the next line so I have to use RichText.
Similar to
Sample Code:
ListView(
children:[
RichText(
children: AListOfTextSpansThatICreateWithIndexes(),
),
],
),
Sample Text That I want to show:
This is TextSpan1 and it is a bit
long. This is TextSpan2 and its ok.
Similar to Scrollable position of a TextSpan within a RichText
There is a way to make sure a key is visible on the screen using the Scrollable.ensureVisible method. (credits to the person who deleted their comment)
you should first generate keys for your list:
var keys = List.generate(LENGTH, (i) => GlobalKey());
Then use the keys behind each TextSpan:
Text.rich(
TextSpan(
children: Iterable.generate(LENGTH, (i) => i)
.expand((i) => [
WidgetSpan(
child: SizedBox.fromSize(
size: Size.zero,
key: keys[i],
),
),
TextSpan(
text: 'this is text number $i',
),
])
.toList(),
),
),
Finally, call this function(where there is access to the context) to scroll to the desired key:
Scrollable.ensureVisible(
keys[i].currentContext,
alignment: 0.2,
duration: Duration(milliseconds: 500),
),
I am trying to use Navigator.pop(context); in an appbar but the problem is that it shows a black screen and then you have to press the back button on android then it pops current black screen, so where is this black screen coming from that I don't know and in iPhone there is no back button so that why it is stuck in that screen. Please do help me
This is the code where I am using this Navigator code.
#override
Widget build(BuildContext context) {
return new Scaffold(
backgroundColor: Color.fromRGBO(30, 30, 30, 1.0),
appBar: new AppBar(
elevation: 0.0,
backgroundColor: Color.fromRGBO(30, 30, 30, 1.0),
actions: <Widget>[
new IconButton(
icon: Icon(Icons.settings_power),
onPressed: () {
Navigator.pop(context);
}),
],
title: new Text(
"PROLOG",
style: new TextStyle(color: Colors.white),
),
centerTitle: true,
),
);
}
and the most strange thing is that I am using this piece of code in another class its working fine. So where is the problem...
The reason why you're getting a black/blank screen after calling Navigator.pop(context) is because there's no widget/screen beyond the current Navigator stack.
In Flutter, SystemChannels.platform.invokeMethod('SystemNavigator.pop') is used to remove the topmost Flutter instance. As mentioned in the docs, the method should remove the current Activity from the stack in Android. The behavior is a bit different on iOS though.
If you're trying to implement this function to close the app, this is highly discouraged. This is pointed out on Apple's archived doc. I'm trying to search for an updated reference, but navigating through Apple's Developer docs is challenging.
Anyway, I've made some changes to your code snippet if you'd like to try this out.
Add this in your imports
import 'dart:io' show Platform, exit;
As for the code, exit(int) is used for iOS. It's recommended to use an exit code from the range 0...127 as mentioned in the docs. While SystemChannels.platform.invokeMethod('SystemNavigator.pop') is used for other platforms (mainly Android in this case).
Widget build(BuildContext context) {
return new Scaffold(
backgroundColor: Color.fromRGBO(30, 30, 30, 1.0),
appBar: new AppBar(
elevation: 0.0,
backgroundColor: Color.fromRGBO(30, 30, 30, 1.0),
actions: <Widget>[
new IconButton(
icon: Icon(Icons.settings_power),
// if Platform is iOS call exit(0)
// else call the preferred method
// https://api.flutter.dev/flutter/services/SystemNavigator/pop.html
onPressed: () => Platform.isIOS
? exit(0)
: SystemChannels.platform.invokeMethod('SystemNavigator.pop'),
),
],
title: new Text(
"PROLOG",
style: new TextStyle(color: Colors.white),
),
centerTitle: true,
),
);
}
Demo