text
stringlengths
1
372
setState(() {
data = jsonDecode(response.body);
});
}
widget getBody() {
if (showloadingdialog) {
return getProgressDialog();
}
return getListView();
}
widget getProgressDialog() {
return const center(child: CircularProgressIndicator());
}
ListView getListView() {
return ListView.builder(
itemCount: data.length,
itemBuilder: (context, index) {
return getRow(index);
},
);
}
widget getRow(int index) {
return padding(
padding: const EdgeInsets.all(10),
child: Text('Row ${data[index]['title']}'),
);
}
@override
widget build(BuildContext context) {
return scaffold(
appBar: AppBar(title: const Text('Sample app')),
body: getBody(),
);
}
}
<code_end>
<topic_end>
<topic_start>
project structure & resources
<topic_end>
<topic_start>
where do i store my image files?
Xamarin.Forms has no platform independent way of storing images,
you had to place images in the iOS xcasset folder,
or on android in the various drawable folders.
while android and iOS treat resources and assets as distinct items,
flutter apps have only assets.
all resources that would live in the
resources/drawable-* folders on android,
are placed in an assets’ folder for flutter.
flutter follows a simple density-based format like iOS.
assets might be 1.0x, 2.0x, 3.0x, or any other multiplier.
flutter doesn’t have dps but there are logical pixels,
which are basically the same as device-independent pixels.
flutter’s devicePixelRatio expresses the ratio
of physical pixels in a single logical pixel.
the equivalent to android’s density buckets are:
assets are located in any arbitrary folder—
flutter has no predefined folder structure.
you declare the assets (with location)
in the pubspec.yaml file, and flutter picks them up.
to add a new image asset called my_icon.png to our flutter project,
for example, and deciding that it should live in a folder we
arbitrarily called images, you would put the base image (1.0x)
in the images folder, and all the other variants in sub-folders
called with the appropriate ratio multiplier:
next, you’ll need to declare these images in your pubspec.yaml file:
you can directly access your images in an image.asset widget:
<code_start>
@override
widget build(BuildContext context) {
return image.asset('images/my_icon.png');
}
<code_end>
or using AssetImage:
<code_start>
@override
widget build(BuildContext context) {
return const image(
image: AssetImage('images/my_image.png'),
);
}
<code_end>
more detailed information can be found in adding assets and images.
<topic_end>
<topic_start>
where do i store strings? how do i handle localization?
unlike .net which has resx files,
flutter doesn’t currently have a dedicated system for handling strings.
at the moment, the best practice is to declare your copy text
in a class as static fields and access them from there. for example:
<code_start>
class strings {
static const string welcomeMessage = 'welcome to flutter';
}
<code_end>
you can access your strings as such:
<code_start>
Text(Strings.welcomeMessage);
<code_end>