best-flutter / flutter_dropdown_menu

A dropdown menu for Flutter.

flutter_dropdown_menu

A dropdown menu for Flutter.

Showcase

---

Table of contents

Installion

dropdown_menu: ^1.1.0

Build simple list menu

Build tree menu

Build custom menu

How to use

Examples

seemain.dart

flutter_dropdown_menu's Issues

自由度不够

这个工具没有三级联动的功能

大佬有时间出下这个库的教程吗

列表项添加点击跳转到其他页面之后回来, 下拉菜单就不会弹出了

获取选项的id值

怎么获取选项的id值？代码找了半天没找到 T_T

请问item点击事件在哪里呢？

翻了翻源码，item的点击回调在哪里？没有找到

Example is blank.

Example is blank.

catch onSelectedItem

After successfully implemented your drop-down menu I would like to know how can I catch when an item is selected/changed.
Thank you for reading, nice work

DropdownMenu 里面的 onHide方法不是选择完后的回调吗，看了下源码，被注释掉了，我需要一个回调来执行选择后的操作

Error: A value of type '#lib1::TickerFuture' can't be assigned to a variable of type 'dart.async::Future<dart.core::Null>'.

Compiler message:
file:///Users/xxx/Desktop/FlutterDemo/flutter_dropdown_menu-master/lib/_src/dropdown_menu.dart:271:16: Error: A value of type '#lib1::TickerFuture' can't be assigned to a variable of type 'dart.async::Futuredart.core::Null'.
Try changing the type of the left hand side, or casting the right hand side to 'dart.async::Futuredart.core::Null'.
return onHide();
^
file:///Users/xxx/Desktop/FlutterDemo/flutter_dropdown_menu-master/lib/_src/dropdown_menu.dart:310:12: Error: A value of type '#lib1::TickerFuture' can't be assigned to a variable of type 'dart.async::Futuredart.core::Null'.
Try changing the type of the left hand side, or casting the right hand side to 'dart.async::Futuredart.core::Null'.
return _handleShow(index, true);

_ElementLifecycle.defunct': is not true.

Either the assertion indicates an error in the framework itself,
or we should provide substantially more information in this error
message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on
GitHub:
https://github.com/flutter/flutter/issues/new?template=BUG.md

When the exception was thrown, this was the stack:
2 Element.markNeedsBuild (package:flutter/src/widgets/framework.dart:3641:12)
3 State.setState (package:flutter/src/widgets/framework.dart:1161:14)
4 _DropdownMenuState._handleShow (package:dropdown_menu/_src/dropdown_menu.dart:316:5)
5 _DropdownMenuState.onShow (package:dropdown_menu/_src/dropdown_menu.dart:310:12)
6 _DropdownMenuState.onEvent (package:dropdown_menu/_src/dropdown_menu.dart:355:11)
7 DropdownState._onController (package:dropdown_menu/_src/drapdown_common.dart:189:5)
8 ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:206:21)
9 DropdownMenuController.show (package:dropdown_menu/_src/drapdown_common.dart:39:5)
10 _DropdownHeaderState.buildItem. (package:dropdown_menu/_src/dropdown_header.dart:88:24)
11 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
12 TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:365:11)
13 TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:275:7)
14 PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:455:9)
15 PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:75:13)
16 PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:102:11)
17 _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:218:19)
18 _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:198:22)
19 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)
20 _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)
21 _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)
25 _invoke1 (dart:ui/hooks.dart:250:10)
26 _dispatchPointerDataPacket (dart:ui/hooks.dart:159:5)
(elided 5 frames from class _AssertionError and package dart:async)

The DropdownMenuController sending notification was:
Instance of 'DropdownMenuController'

_DropdownMenuState#f9cfe(tickers: tracking 1 ticker) was disposed with an active Ticker

flutter: ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞════════════════════════
The following assertion was thrown while finalizing the widget
tree:
_DropdownMenuStatef9cfe(tickers: tracking 1 ticker) was disposed
with an active Ticker.
_DropdownMenuState created a Ticker via its
TickerProviderStateMixin, but at the time dispose() was called on
the mixin, that Ticker was still active. All Tickers must be
disposed before calling super.dispose(). Tickers used by
AnimationControllers should be disposed by calling dispose() on
the AnimationController itself. Otherwise, the ticker will leak.
The offending ticker was: _WidgetTicker(created by
_DropdownMenuStatef9cfe(lifecycle state: created, tickers:
tracking 3 tickers))
The stack trace when the _WidgetTicker was actually created was:
0 new Ticker.
(package:flutter/src/scheduler/ticker.dart:64:40)
1 new Ticker
(package:flutter/src/scheduler/ticker.dart:66:6)
2 new _WidgetTicker
(package:flutter/src/widgets/ticker_provider.dart:225:80)
3
__DropdownMenuState&DropdownState&TickerProviderStateMixin.createTicker
(package:flutter/src/widgets/ticker_provider.dart:161:34)
4 new AnimationController
(package:flutter/src/animation/animation_controller.dart:245:21)
5 _DropdownMenuState.initState
(package:dropdown_menu/_src/dropdown_menu.dart:132:27)
6 StatefulElement._firstBuild
(package:flutter/src/widgets/framework.dart:4033:58)
7 ComponentElement.mount
(package:flutter/src/widgets/framework.dart:3902:5)
8 Element.inflateWidget
(package:flutter/src/widgets/framework.dart:3084:14)
9 Element.updateChild
(package:flutter/src/widgets/framework.dart:2887:12)
10 RenderObjectElement.updateChildren
(package:flutter/src/widgets/framework.dart:4875:32)
11 MultiChildRenderObjectElement.update
(package:flutter/src/widgets/framework.dart:5208:17)
12 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
13 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
14 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
15 ProxyElement.update
(package:flutter/src/widgets/framework.dart:4219:5)
16 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
17 RenderObjectElement.updateChildren
(package:flutter/src/widgets/framework.dart:4817:32)
18 MultiChildRenderObjectElement.update
(package:flutter/src/widgets/framework.dart:5208:17)
19 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
20 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
21 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
22 ProxyElement.update
(package:flutter/src/widgets/framework.dart:4219:5)
23 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
24 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
25 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
26 StatefulElement.update
(package:flutter/src/widgets/framework.dart:4085:5)
27 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
28 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
29 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
30 ProxyElement.update
(package:flutter/src/widgets/framework.dart:4219:5)
31 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
32 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
33 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
34 ProxyElement.update
(package:flutter/src/widgets/framework.dart:4219:5)
35 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
36 RenderObjectElement.updateChildren
(package:flutter/src/widgets/framework.dart:4817:32)
37 MultiChildRenderObjectElement.update
(package:flutter/src/widgets/framework.dart:5208:17)
38 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
39 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
40 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
41 StatefulElement.update
(package:flutter/src/widgets/framework.dart:4085:5)
42 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
43 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
44 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
45 ProxyElement.update
(package:flutter/src/widgets/framework.dart:4219:5)
46 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
47 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
48 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
49 StatefulElement.update
(package:flutter/src/widgets/framework.dart:4085:5)
50 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
51 SingleChildRenderObjectElement.update
(package:flutter/src/widgets/framework.dart:5099:14)
52 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
53 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
54 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
55 StatelessElement.update
(package:flutter/src/widgets/framework.dart:3981:5)
56 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
57 SingleChildRenderObjectElement.update
(package:flutter/src/widgets/framework.dart:5099:14)
58 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
59 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
60 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
61 StatefulElement.update
(package:flutter/src/widgets/framework.dart:4085:5)
62 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
63 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
64 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
65 StatefulElement.update
(package:flutter/src/widgets/framework.dart:4085:5)
66 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
67 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
68 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
69 ProxyElement.update
(package:flutter/src/widgets/framework.dart:4219:5)
70 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
71 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
72 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
73 ProxyElement.update
(package:flutter/src/widgets/framework.dart:4219:5)
74 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
75 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
76 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
77 StatefulElement.update
(package:flutter/src/widgets/framework.dart:4085:5)
78 Element.updateChild
(package:flutter/src/widgets/framework.dart:2876:15)
79 ComponentElement.performRebuild
(package:flutter/src/widgets/framework.dart:3935:16)
80 Element.rebuild
(package:flutter/src/widgets/framework.dart:3721:5)
81 BuildOwner.buildScope
(package:flutter/src/widgets/framework.dart:2340:33)
82
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame
(package:flutter/src/widgets/binding.dart:700:20)
83
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback
(package:flutter/src/rendering/binding.dart:285:5)
84
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback
(package:flutter/src/scheduler/binding.dart:1016:15)
85
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame
(package:flutter/src/scheduler/binding.dart:958:9)
86
_WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame
(package:flutter/src/scheduler/binding.dart:874:5)
90 _invoke (dart:ui/hooks.dart:236:10)
91 _drawFrame (dart:ui/hooks.dart:194:3)
(elided 3 frames from package dart:async)

When the exception was thrown, this was the stack:
0 __DropdownMenuState&DropdownState&TickerProviderStateMixin.dispose. (package:flutter/src/widgets/ticker_provider.dart:178:13)
1 __DropdownMenuState&DropdownState&TickerProviderStateMixin.dispose (package:flutter/src/widgets/ticker_provider.dart:191:6)
2 _DropdownMenuState.dispose (package:dropdown_menu/_src/dropdown_menu.dart:147:11)
3 StatefulElement.unmount (package:flutter/src/widgets/framework.dart:4107:12)
4 _InactiveElements._unmount (package:flutter/src/widgets/framework.dart:1737:13)
5 ListIterable.forEach (dart:_internal/iterable.dart:39:13)
6 _InactiveElements._unmountAll (package:flutter/src/widgets/framework.dart:1746:25)
7 BuildOwner.finalizeTree. (package:flutter/src/widgets/framework.dart:2426:27)
8 BuildOwner.lockState (package:flutter/src/widgets/framework.dart:2258:15)
9 BuildOwner.finalizeTree (package:flutter/src/widgets/framework.dart:2425:7)
10 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:702:18)
11 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&SemanticsBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:285:5)
12 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1016:15)
13 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:958:9)
14 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:874:5)
18 _invoke (dart:ui/hooks.dart:236:10)
19 _drawFrame (dart:ui/hooks.dart:194:3)
(elided 3 frames from package dart:async)

This project seems abandoned

自由度差的远

1 无法设置宽高，
2 无法设置弹出位置，只能在顶部弹出。
3 四个方向的偏移

弹出列表时，下方会有白色区域闪烁

点击上方的按钮，弹出下拉菜单的时候，屏幕下方会有一块区域从白色闪动成灰色

菜单栏 会一直超过灰色区域是什么问题

simulator: iphone x

左边菜单栏和邮编菜单栏 下拉的时候 有的时候会正常， 但是大多数的时候 在灰色区域会看得见下面的菜单选项。

还有就是 菜单收起来的时候，灰色区域没有了，菜单还是会在不会消失。

竖向排列的dropdown_menu 怎么实现

三个会一起改变的

动态设置选中项

我需要在 切换到循环时，显示菜单，如果之前已经选择过菜单，切换之后选中项会一直选中，请问这个如何动态设置选中项？