Fix DropdownButtonFormField throws when onChange is null [Flutter core]

AhmedLSayed9 · AhmedLSayed9 · commit 14939bac415f · 2025-03-07T18:08:00.000+02:00
diff --git a/packages/dropdown_button2/lib/src/dropdown_button2.dart b/packages/dropdown_button2/lib/src/dropdown_button2.dart
@@ -1103,7 +1103,7 @@ class _DropdownButtonFormFieldState<T> extends FormFieldState<T> {
   @override
   void didChange(T? value) {
     super.didChange(value);
-    _dropdownButtonFormField.onChanged!(value);
+    _dropdownButtonFormField.onChanged?.call(value);
   }
 
   @override
@@ -1117,6 +1117,6 @@ class _DropdownButtonFormFieldState<T> extends FormFieldState<T> {
   @override
   void reset() {
     super.reset();
-    _dropdownButtonFormField.onChanged!(value);
+    _dropdownButtonFormField.onChanged?.call(value);
   }
 }

Original file line number	Diff line number	Diff line change
`@@ -1103,7 +1103,7 @@ class _DropdownButtonFormFieldState<T> extends FormFieldState<T> {`
`1103`	`1103`	`@override`
`1104`	`1104`	`void didChange(T? value) {`
`1105`	`1105`	`super.didChange(value);`
`1106`		`- _dropdownButtonFormField.onChanged!(value);`
	`1106`	`+ _dropdownButtonFormField.onChanged?.call(value);`
`1107`	`1107`	`}`
`1108`	`1108`
`1109`	`1109`	`@override`
`@@ -1117,6 +1117,6 @@ class _DropdownButtonFormFieldState<T> extends FormFieldState<T> {`
`1117`	`1117`	`@override`
`1118`	`1118`	`void reset() {`
`1119`	`1119`	`super.reset();`
`1120`		`- _dropdownButtonFormField.onChanged!(value);`
	`1120`	`+ _dropdownButtonFormField.onChanged?.call(value);`
`1121`	`1121`	`}`
`1122`	`1122`	`}`