1

lib/chat/ChatPage.dart

@@ -617,7 +617,7 @@ class _ChatPageState extends State<ChatPage> {
   double zoomButtonSizeHeight = 74;
 
   void dragEvent(DragUpdateDetails details) {
-    final RenderObject box = context.findRenderObject();
+    final RenderObject F = context.findRenderObject();
     //  获得自定义Widget的大小，用来计算Widget的中心锚点
     dx = details.globalPosition.dx - mykey.currentContext.size.width / 2;
     dy = details.globalPosition.dy - mykey.currentContext.size.height / 2;

lib/home/coin_anim.dart

@@ -0,0 +1,46 @@
+import 'package:flutter/material.dart';
+
+import '../r.dart';
+
+class CoinAnim extends StatefulWidget {
+  @override
+  _CoinAnimState createState() => _CoinAnimState();
+}
+
+class _CoinAnimState extends State<CoinAnim>
+    with SingleTickerProviderStateMixin {
+  Animation<double> _animation;
+  AnimationController _controller;
+  double begin = 100;
+  double end = 20;
+
+  @override
+  void initState() {
+    super.initState();
+    // 启动动画controller
+    _controller = new AnimationController(
+        duration: Duration(milliseconds: 500), vsync: this);
+    _controller.addStatusListener((AnimationStatus status) {});
+
+    _animation = new Tween<double>(begin: begin, end: end).animate(_controller)
+      ..addListener(() {
+        setState(() {});
+      });
+
+    _controller.forward(from: begin);
+  }
+
+  @override
+  void dispose() {
+    _controller.stop();
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Positioned(
+        child: Container(
+            height: _animation.value, child: Image.asset(R.assetsImagesCoin)));
+  }
+}