text
stringlengths 1
372
|
---|
aligning components horizontally
|
in SwiftUI, stack views play a big part in designing your layouts.
|
two separate structures allow you to create stacks:
|
HStack for horizontal stack views
|
VStack for vertical stack views
|
the following SwiftUI view adds a globe image and
|
text to a horizontal stack view:
|
flutter uses row rather than HStack:
|
<code_start>
|
row(
|
mainAxisAlignment: MainAxisAlignment.center,
|
children: [
|
Icon(CupertinoIcons.globe),
|
Text('Hello, world!'),
|
],
|
),
|
<code_end>
|
the row widget requires a List<Widget> in the children parameter.
|
the mainAxisAlignment property tells flutter how to position children
|
with extra space. MainAxisAlignment.center positions children in the
|
center of the main axis. for row, the main axis is the horizontal
|
axis.
|
<topic_end>
|
<topic_start>
|
aligning components vertically
|
the following examples build on those in the previous section.
|
in SwiftUI, you use VStack to arrange the components into a
|
vertical pillar.
|
flutter uses the same dart code from the previous example,
|
except it swaps column for row:
|
<code_start>
|
column(
|
mainAxisAlignment: MainAxisAlignment.center,
|
children: [
|
Icon(CupertinoIcons.globe),
|
Text('Hello, world!'),
|
],
|
),
|
<code_end>
|
<topic_end>
|
<topic_start>
|
displaying a list view
|
in SwiftUI, you use the list base component to display sequences
|
of items.
|
to display a sequence of model objects, make sure that the user can
|
identify your model objects.
|
to make an object identifiable, use the identifiable protocol.
|
this resembles how flutter prefers to build its list widgets.
|
flutter doesn’t need the list items to be identifiable.
|
you set the number of items to display then build a widget for each item.
|
<code_start>
|
class person {
|
string name;
|
person(this.name);
|
}
|
var items = [
|
Person('Person 1'),
|
Person('Person 2'),
|
Person('Person 3'),
|
];
|
class HomePage extends StatelessWidget {
|
const HomePage({super.key});
|
@override
|
widget build(BuildContext context) {
|
return scaffold(
|
body: ListView.builder(
|
itemCount: items.length,
|
itemBuilder: (context, index) {
|
return ListTile(
|
title: text(items[index].name),
|
);
|
},
|
),
|
);
|
}
|
}
|
<code_end>
|
flutter has some caveats for lists:
|
the ListView widget has a builder method.
|
this works like the ForEach within SwiftUI’s list struct.
|
the itemCount parameter of the ListView sets how many items
|
the ListView displays.
|
the itemBuilder has an index parameter that will be between zero
|
and one less than itemCount.
|
the previous example returned a ListTile widget for each item.
|
the ListTile widget includes properties like height and font-size.
|
these properties help build a list. however, flutter allows you to return
|
almost any widget that represents your data.
|
<topic_end>
|
<topic_start>
|
displaying a grid
|
when constructing non-conditional grids in SwiftUI,
|
you use grid with GridRow.
|
to display grids in flutter, use the GridView widget.
|
this widget has various constructors. each constructor has
|
a similar goal, but uses different input parameters.
|
the following example uses the .builder() initializer:
|
<code_start>
|
const widgets = [
|
Text('Row 1'),
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.