I have an image and I want to create a row of 5 copies of that image. The simplest way I see of doing that is the following:
Row(
children: <Widget>[
Expanded(
child: Image.asset('images/penny.png'),
),
Expanded(
child: Image.asset('images/penny.png'),
),
Expanded(
child: Image.asset('images/penny.png'),
),
Expanded(
child: Image.asset('images/penny.png'),
),
Expanded(
child: Image.asset('images/penny.png'),
),
],
),
However, this approach is obviously incredibly repetitive. I could write a function for the Expanded widget to make it look a little cleaner, but is there a better approach that is less repetitive and will allow me to easily control how many duplicate images I can create?
Container(
child: Row(
children: List.generate(
5,
(index) => Expanded(
child:
Image.asset('assets/yourImage'))),
))
I found a way of doing it with GridView, so I think I'll use this, as it'll also be useful later when I want to create more pennies. (Like for 100 pennies, I would want to display them in several rows and not just one.)
GridView.count(
crossAxisCount: 5 ,
children: List.generate(5,(index){
return Container(
child: Image.asset('images/penny.png'),
);
}),
)
To make this even more customizable:
GridView build2DArrayOfPennies(int rowCount, int numItems, String imageFile) {
return GridView.count(
crossAxisCount: rowCount,
children: List.generate(numItems,(index){
return Container(
child: Image.asset(imageFile),
);
}),
);
Related
Can anyone clarify for me what I have shown in the 'image' attached is achievable in flutter? if yes, how? explaining the image is a bit hard.
I am new to flutter and trying to nest some scrollable views inside each other.
at first I tried to achieve this by nesting simple scrollable row and columns inside each other but faced some errors and exceptions (unbound height and width).
I searched and found out it is better to use 'CustomScrollView' for nesting lists in each other. tried it but haven't achieved what I want yet.
Any help/hint on how to achieve this would be much appreciated.
Nested Scroll Views
This is definitely possible, and you could use an approach like below, which is inspired by another question on stack overflow. I recommend reading that for better clarification -- here.
Edit: Wrapping the Row widget in a SingleChildScrollView would make the entire page scrollable.
body: Row(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Expanded(
child: ListView.builder(
scrollDirection: Axis.vertical,
itemCount: X,
itemBuilder: (BuildContext context, int index) => ...
),
),
Expanded(
child: ListView.builder(
scrollDirection: Axis.vertical,
itemCount: Y,
itemBuilder: (BuildContext context, int index) => ...
),
),
],
);
If this doesn't help, I'd suggest finding flutter repositories of e.g. Netflix clones or other existing apps known to have scroll views inside a list view.
#bragi, thanks for the answer,
I followed what you suggested and after some trial and error, I finally got it working.
But in terms of efficiency and how the application will respond/render I am not sure if this was the best way to do it:
SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: Row(
// mainAxisSize: MainAxisSize.min,
children: [
makeColumn(),
makeColumn(),
makeColumn(),
makeColumn(),
makeColumn(),
],
),
),
Widget makeColumn() {
return Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
children: [
Container(
width: 150,
height: 150,
color: Colors.green,
),
SizedBox(
width: 150,
height: 500,
child: SingleChildScrollView(
scrollDirection: Axis.vertical,
child: Column(
children: [
Container(), ....
For some reason, the Expanded widget did not work so I had to wrap my second column with SizedBox!
return Scaffold(
body: Center(
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Container(
color: Colors.red,
width: MediaQuery.of(context).size.width,
height: MediaQuery.of(context).size.height,
child: Center(
child: SelectGroupCard(context, titles: titles, ids: ids,
onTap: (title, id) {
setState(() {
cardGroupResult = title + " " + id;
});
}),
),
),
],
),
There are several cards as seen in the picture. I want to get these right out. I even want to be able to show these cards in the middle of the page, in 3 columns, 4 rows.
Use widget GridView, it allows you to select the desired number of columns and rows. Also, it is possible to install paddings.
you can use GridView
GridView(
gridDelegate:const SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2, // you can change this
),
children :[...] // put your cards here !
)
you can remove the width property of SelectGroupCard. for example, if SelectGroupCard is a row widget, the following code like this:
Row(
mainAxisSize: MainAxisSize.min,
children: [],
)
I am trying to get the layout as in the gif below but could not get any resource to continue with. There are two rows with multiple columns and is scrollable. How can I achieve such layout?
As your question says, you follow this approach, and it is not containing multiple columns, items are having different width. This snippet will work fine.
SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: Column(
children: [
Row(
key: const ValueKey("row1"),
children: _items(),
),
Row(
key: const ValueKey("row2"),
children: _items(),
),
],
),
),
You can achieve this by SingleChildScrolView widget with axis : horizontal and that listitem will be created using FilterChip widget.
like this :
SingleChildScrollView(
scrollDirection: Axis.horizontal,
child: Wrap(
spacing: 10.0,
runSpacing: 5.0,
children: [...generateTags()],
),
),
generateTags(){
return _keywords.map((e) => FilterChip(label : e)).toList();
}
var _keywords =["hello" , "hi" ,"words 1" , "word 2"];
I'm trying to make a column with two children begin at a certain position on the screen. The 2nd child is a dynamic ListView where I do not want the number of children changing the position of the column.
How is this possible?
Just wrap your ListView with Expanded widget .
Example:
Column(
children: [
Expanded( //here
child: ListView.builder(
itemBuilder: (context, index) => Text('test $index'),
itemCount: 50, ),
),
Column(
children: [
Container(height: 100, color: Colors.yellow),
OutlinedButton(onPressed: (){}, child: Text('Test'),),
Text('Another Test')
]
)
],
),
I used a Listview.builder because I don't want to do it one by one. Just for the example
You can learn more about Expanded widget by watching this Official video or by visiting flutter.dev
I have a page with container + listView. Now the listView is scrollable, but I would like the whole page to be scrollable. (so if the user scrolls, the container goes 'away')
Column(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
children: posts,
),
],
),
Is this possible, and how can it be achieved?
Thanks!
You can wrap the whole page with a SingleChildScrollView
here is an example:
SingleChildScrollView( // <- added
child: Column(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
shrinkWrap: true, // <- added
primary: false, // <- added
children: posts,
),
],
),
);
for more info about see this question
What if you don't use Column and use ListView.builder and
according to indexes you show the widget.
For example on 0 index you show the Container.
This way you don't have to use any different widget for scrolling
and as per your requirement the container will scroll with the list.
This way there is no chance that you will get any overflow error
like you were getting while using Column.
Plus point of ListView.builder is that your posts will be created lazily and that is efficient way of creating ListView in Flutter. No matter how many posts you have your UI will not lag.
This at first may look like a hack but according to your requirement that the container must also be able to get scrolled, this solution makes sense to me because Container can be considered as a first element of the list.
Let me know if it works for you or not.
Following is the working code for your reference:
#override
Widget build(BuildContext context) {
return ListView.builder(
itemCount: posts.length + 1, // +1 because you are showing one extra widget.
itemBuilder: (BuildContext context, int index) {
if (index == 0) {
return Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text(""));
}
int numberOfExtraWidget = 1; // here we have 1 ExtraWidget i.e Container.
index = index - numberOfExtraWidget; // index of actual post.
return posts[index];
},
);
}
I hope this works for you, in case of any doubt please comment.
There are multiple ways you can achieve what you want. The only problem is that if you have large number of posts, listview with children posts, as shrinkWrap is set to true, will take time to calculate its required height, for that it will have to populate all of its children.
First
ListView(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
physics: NeverScrollableScrollPhysics(),
primary: false,
shrinkWrap: true,
children: posts,
),
),
],
),
Second
SingleChildScrollView(
child: Column(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
physics: NeverScrollableScrollPhysics(),
shrinkWrap: true,
primary: false,
children: posts,
),
],
),
),
use SingleChildScrollView then Container with hard coded container height, then list view builder, that should fix your issue.
I tried the following:
SingleChildScrollView(
child: Container(
height: 1000,
width: 400,
child: ListView(
children: <Widget>[
Container(
color: Colors.white.withOpacity(0.95),
width: 400,
height: 400,
child: Text("")),
ListView(
children: posts,
),
],
),
),
),
This works, but I would like that the container has a dynamic height and width? Is that possible? Thanks!