在较新版本的 Vue 下使用，拖动滚动条会出现闪动

[aisin]

当组件在 Vue 高于 v2.5.0 (含 v2.5.0) 版本使用时，拖动滚动条时内容会出现闪动，拖动稍快时甚至会出现白屏，但使用 v2.4.4 及以下版本则无此问题。

可以参见 DEMO：https://jsfiddle.net/aisin/h6u2km1a/34/

[sally2015]

这是什么原因呢？可以enhance哪里的代码？ @tangbc

[lkho]

It's due to the change of nextTick implementation in Vue 2.5

https://jsfiddle.net/llkho/j21tmq85/6/

The newer version is using MessageChannel while old one is using Promise.then.
I think there's not much to 'enhance' at the plugin's side.

Edit:

In latest Vue version (2.5.21) at the current time, there are separated macroTimerFunc and microTimerFunc inside nextTick implementation, and the docs mentioned calling nextTick inside v-on handlers are forced to use macroTimerFunc (see https://github.com/vuejs/vue/releases/tag/v2.5.0 , 'Internals' section at the bottom).

If the issue really matters, you can bypass Vue's nextTick by wrapping the this.$forceUpdate call inside your own microTimerFunc, e.g.

Promise.resolve().then(() => this.$forceUpdate())

vue-virtual-scroll-list/index.js

Lines 135 to 138 in 62b2435

	delta.end = zone.end
	delta.start = zone.start
	this.$forceUpdate()
	},

and it will escape from the v-on handler's default macroTimerFunc behaviour.

[tangbc]

It's fixed in latest version.