Flutter call function from other class? - flutter

Question

Hi I am building flutter function which able to capture qr code and after display the result after user scan QR Code. I need user to be able navigate to previous scanning screen by using button if they need rescan or scan new qr code. This is code for button which on Scanview class.
SizedBox(height: 40,),
CupertinoButton(
color: Color(0xFF88070B),
child:Text("Re-scan QR "),
onPressed: (){
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => **ScanFunction**(),
),
);
}
)
I want to call this _scanQR method from other class ScanFunction . What is proper way when user tap Re-scan QR button and call _scanQR method which is on other class? How to access method from other class? Thanks for help.
class ScanFunction extends StatefulWidget {
#override
ScanFunctionState createState() {
return ScanFunctionState();
}
}
class ScanFunctionState extends State<ScanFunction> {
String result = "Maklumat Inventori";
Future _scanQR() async {
try {
String qrResult = await BarcodeScanner.scan();
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => Scanresultview(qrResult),
),
);
} on PlatformException catch (ex) {
if (ex.code == BarcodeScanner.CameraAccessDenied) {
setState(() {
result = "Kebenaran kamera telah ditolak";
});
} else {
setState(() {
result = "Ralat tidak diketahui$ex";
});
}
} on FormatException {
setState(() {
result = "Anda menekan butang belakang sebelum mengimbas apa-apa";
});
} catch (ex) {
setState(() {
result = "Ralat tidak diketahui $ex";
});
}
}

Answer 1

You can call this method from initState.
class ScanFunction extends StatefulWidget {
#override
ScanFunctionState createState() {
return ScanFunctionState();
}
}
class ScanFunctionState extends State<ScanFunction> {
#override
void initState() {
_scanQR();
super.initState();
}
String result = "Maklumat Inventori";
Future _scanQR() async {
try {
String qrResult = await BarcodeScanner.scan();
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => Scanresultview(qrResult),
),
);
} on PlatformException catch (ex) {
if (ex.code == BarcodeScanner.CameraAccessDenied) {
setState(() {
result = "Kebenaran kamera telah ditolak";
});
} else {
setState(() {
result = "Ralat tidak diketahui$ex";
});
}
} on FormatException {
setState(() {
result = "Anda menekan butang belakang sebelum mengimbas apa-apa";
});
} catch (ex) {
setState(() {
result = "Ralat tidak diketahui $ex";
});
}
}