透明度动画

lib/muyu/animate_text.dart

@@ -0,0 +1,45 @@
+import 'package:flutter/material.dart';
+
+class AnimateText extends StatefulWidget {
+  final String text;
+
+  const AnimateText({Key? key, required this.text}) : super(key: key);
+
+  @override
+  State<AnimateText> createState() => _FadTextState();
+}
+
+class _FadTextState extends State<AnimateText> with SingleTickerProviderStateMixin {
+  late AnimationController controller;
+  late Animation<double> opacity;
+  late Animation<Offset> position;
+  late Animation<double> scale;
+
+  @override
+  void initState() {
+    super.initState();
+    controller = AnimationController(vsync: this, duration: const Duration(milliseconds: 500));
+    opacity = Tween(begin: 1.0, end: 0.0).animate(controller);
+    controller.forward();
+  }
+
+  @override
+  void didUpdateWidget(covariant AnimateText oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    controller.forward(from: 0);
+  }
+
+  @override
+  void dispose() {
+    controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return FadeTransition(
+      opacity: opacity,
+      child: Text(widget.text),
+    );
+  }
+}