50% sftp

lib/view/widget/fade_in.dart

@@ -0,0 +1,44 @@
+import 'package:flutter/material.dart';
+
+/// 渐隐渐显实现
+class FadeIn extends StatefulWidget {
+  final Widget child;
+
+  const FadeIn({Key? key, required this.child}) : super(key: key);
+
+  @override
+  _MyFadeInState createState() => _MyFadeInState();
+}
+
+class _MyFadeInState extends State<FadeIn> with SingleTickerProviderStateMixin {
+  late AnimationController _controller;
+  late Animation<double> _animation;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 377),
+    );
+    _animation = Tween(
+      begin: 0.0,
+      end: 1.0,
+    ).animate(_controller);
+  }
+
+  @override
+  void dispose() {
+    super.dispose();
+    _controller.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    _controller.forward();
+    return FadeTransition(
+      opacity: _animation,
+      child: widget.child,
+    );
+  }
+}