table: 虚拟滚动闪烁回弹

[margintopt]

Reproduction link

https://stackblitz.com/edit/ng-zorro-antd-start-ouyjnz?file=src/app/app.component.ts

Steps to reproduce

table中使用虚拟滚动 且有ngIf等判断

What is expected?

正常滚动

What is actually happening?

table中ngIf越多 滚动闪烁情况越严重 甚至会出现无法向下滚动回弹的效果

Environment	Info
ng-zorro-antd	7.4.1
Browser	Google Chrome 74.0.3729.169（正式版本） （64 位）

[ng-zorro-bot]

Translation of this issue:

---

table: Virtual scrolling flashback rebound

Reproduction link

[https://stackblitz.com/edit/ng-zorro-antd-start-ouyjnz?file=src/app/app.component.ts](https://stackblitz.com/edit/ng-zorro-antd- Start-ouyjnz?file=src/app/app.component.ts)

Steps to reproduce

Use virtual scrolling in table and judge with ngIf

What is expected?

Normal scrolling

What is actually happening?

The more ngIf in the table, the more serious the scrolling situation, and even the effect of not being able to scroll down.

Environment	Info
ng-zorro-antd	7.4.1
Browser	Google Chrome 74.0.3729.169 (official version) (64-bit)

[vthinkxie]

你设定的 [nzVirtualItemSize]="65" ，但是明显每行高度不是65px，请仔细阅读文档