From 8f5f20ee0c2e0170428f32c6c2ef67d03d137d3b Mon Sep 17 00:00:00 2001
From: LiJianGe <jiange.li@56qq.com>
Date: Wed, 12 Sep 2018 11:57:18 +0800
Subject: [PATCH] =?UTF-8?q?fix=20issue=20#3=20=E5=88=97=E8=A1=A8=E9=A1=B9?=
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原因: 跳转到其他页面的时候会重复调用 didChangeDependencies , 导致添加多个 listener , 回到页面之后点击时会重复触发点击事件, 开启 => 关闭
---
 lib/drapdown_common.dart | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/drapdown_common.dart b/lib/drapdown_common.dart
index b61be4b..07b6b8b 100644
--- a/lib/drapdown_common.dart
+++ b/lib/drapdown_common.dart
@@ -1,5 +1,5 @@
-import 'package:flutter/widgets.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
 
 enum DropdownEvent {
   // the menu will hide
@@ -158,14 +158,16 @@ abstract class DropdownState<T extends DropdownWidget> extends State<T> {
 
   @override
   void didChangeDependencies() {
-    if (widget.controller == null) {
-      controller = DefaultDropdownMenuController.of(context);
-    } else {
-      controller = widget.controller;
-    }
+    if (controller == null) {
+      if (widget.controller == null) {
+        controller = DefaultDropdownMenuController.of(context);
+      } else {
+        controller = widget.controller;
+      }
 
-    if (controller != null) {
-      controller.addListener(_onController);
+      if (controller != null) {
+        controller.addListener(_onController);
+      }
     }
     super.didChangeDependencies();
   }