FLUT-4313-Sample updated with null safety.

lib/main.dart

@@ -23,14 +23,8 @@ class MultiplePickerSample extends StatefulWidget {
 }
 
 class _MultiplePickerSampleState extends State<MultiplePickerSample> {
-  DateRangePickerController _controller;
-  String _headerString;
-
-  @override
-  void initState() {
-    _controller = DateRangePickerController();
-    super.initState();
-  }
+  final DateRangePickerController _controller = DateRangePickerController();
+  String _headerString = '';
 
   @override
   Widget build(BuildContext context) {
@@ -57,7 +51,7 @@ class _MultiplePickerSampleState extends State<MultiplePickerSample> {
                   highlightColor: Colors.lightGreen,
                   onPressed: () {
                     setState(() {
-                      _controller.backward();
+                      _controller.backward!();
                     });
                   },
                 )),
@@ -82,7 +76,7 @@ class _MultiplePickerSampleState extends State<MultiplePickerSample> {
                   highlightColor: Colors.lightGreen,
                   onPressed: () {
                     setState(() {
-                      _controller.forward();
+                      _controller.forward!();
                     });
                   },
                 )),
@@ -100,10 +94,9 @@ class _MultiplePickerSampleState extends State<MultiplePickerSample> {
               enableMultiView: true,
               onViewChanged: viewChanged,
               monthViewSettings: DateRangePickerMonthViewSettings(
-                  showTrailingAndLeadingDates: true,
                   viewHeaderStyle: DateRangePickerViewHeaderStyle(
-                    backgroundColor: Color(0xFFfcc169),
-                  )),
+                backgroundColor: Color(0xFFfcc169),
+              )),
             ),
           ),
         )
@@ -112,16 +105,18 @@ class _MultiplePickerSampleState extends State<MultiplePickerSample> {
   }
 
   void viewChanged(DateRangePickerViewChangedArgs args) {
-    final int count = (args.visibleDateRange.endDate
-        .difference(args.visibleDateRange.startDate)
-        .inDays);
-     /// For updating proper custom header string if showLeadingAndTrailingDates value as true/false.
+    final DateTime startDate = args.visibleDateRange.startDate!;
+    final DateTime endDate = args.visibleDateRange.endDate!;
+    final int count = endDate.difference(startDate).inDays;
+
     _headerString = DateFormat('MMMM yyyy')
-        .format(args.visibleDateRange.startDate.add(Duration(days: (count * 0.25).toInt())))
-        .toString() + ' - ' +DateFormat('MMMM yyyy')
-        .format(args.visibleDateRange.startDate.add(Duration(days: (count * 0.75).toInt())))
-        .toString();
-    SchedulerBinding.instance.addPostFrameCallback((duration) {
+            .format(startDate.add(Duration(days: (count * 0.25).toInt())))
+            .toString() +
+        ' - ' +
+        DateFormat('MMMM yyyy')
+            .format(startDate.add(Duration(days: (count * 0.75).toInt())))
+            .toString();
+    SchedulerBinding.instance!.addPostFrameCallback((duration) {
       setState(() {});
     });
   }

pubspec.lock

@@ -1,69 +1,62 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  archive:
-    dependency: transitive
-    description:
-      name: archive
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.13"
-  args:
-    dependency: transitive
-    description:
-      name: args
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.6.0"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.4.1"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
-  charcode:
+    version: "2.1.0"
+  characters:
     dependency: transitive
     description:
-      name: charcode
+      name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.3"
-  collection:
+    version: "1.1.0"
+  charcode:
     dependency: transitive
     description:
-      name: collection
+      name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.12"
-  convert:
+    version: "1.2.0"
+  clock:
     dependency: transitive
     description:
-      name: convert
+      name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.1"
-  crypto:
+    version: "1.1.0"
+  collection:
     dependency: transitive
     description:
-      name: crypto
+      name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.4"
+    version: "1.15.0"
   cupertino_icons:
     dependency: "direct main"
     description:
       name: cupertino_icons
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.3"
+    version: "1.0.2"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -74,67 +67,34 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  flutter_web_plugins:
-    dependency: transitive
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  image:
-    dependency: transitive
-    description:
-      name: image
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.12"
   intl:
-    dependency: "direct dev"
+    dependency: "direct main"
     description:
       name: intl
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.16.1"
+    version: "0.17.0"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.6"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.8"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.4"
-  petitparser:
-    dependency: transitive
-    description:
-      name: petitparser
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.4.0"
-  plugin_platform_interface:
-    dependency: transitive
-    description:
-      name: plugin_platform_interface
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.2"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.3"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -146,112 +106,69 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0"
   syncfusion_flutter_core:
     dependency: transitive
     description:
       name: syncfusion_flutter_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "18.2.44"
+    version: "19.1.55"
   syncfusion_flutter_datepicker:
-    dependency: "direct dev"
+    dependency: "direct main"
     description:
       name: syncfusion_flutter_datepicker
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "18.2.44-beta"
+    version: "19.1.55-beta"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.15"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
-  url_launcher:
-    dependency: transitive
-    description:
-      name: url_launcher
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "5.4.2"
-  url_launcher_macos:
-    dependency: transitive
-    description:
-      name: url_launcher_macos
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.0.1+4"
-  url_launcher_platform_interface:
-    dependency: transitive
-    description:
-      name: url_launcher_platform_interface
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.6"
-  url_launcher_web:
-    dependency: transitive
-    description:
-      name: url_launcher_web
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.1.1+1"
-  utf:
-    dependency: transitive
-    description:
-      name: utf
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.9.0+5"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
-  xml:
-    dependency: transitive
-    description:
-      name: xml
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.6.1"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.6.0 <3.0.0"
-  flutter: ">=1.12.8 <2.0.0"
+  dart: ">=2.12.0 <3.0.0"

pubspec.yaml

@@ -14,22 +14,22 @@ description: A new Flutter application.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:
     sdk: flutter
 
+
+  syncfusion_flutter_datepicker: ^19.1.55-beta
+  intl: ^0.17.0
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^0.1.2
+  cupertino_icons: ^1.0.2
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  syncfusion_flutter_datepicker: 18.2.44-beta
-  intl: ">=0.15.0 <0.17.0"
-
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec