factor:布局颜色重构

lib/layout/app_floating_button.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/material.dart';
+
+class AppFloatingButton extends StatelessWidget {
+  final VoidCallback onPressed;
+
+  const AppFloatingButton({super.key, required this.onPressed});
+
+  @override
+  Widget build(BuildContext context) {
+    return FloatingActionButton(
+      onPressed: onPressed,
+      backgroundColor: Colors.transparent,
+      elevation: 0,
+      shape: CircleBorder(),
+      child: Container(
+        width: 50,
+        height: 50,
+        decoration: BoxDecoration(
+          shape: BoxShape.circle,
+          color: Theme.of(context).colorScheme.primary,
+        ),
+        child: Icon(Icons.add, color: Colors.white, size: 36),
+      ),
+    );
+  }
+}