HarmonyOS ForEach、LazyForEach重新渲染item的时候，item里的图片会闪动

有两种方式可以解决该问题。

1.ForEach中的index参数去除

2.给image组件设置缓存

具体可参考：

aboutToAppear(): void {
  app.setImageRawDataCacheSize(1024*1024*100);//缓存 解码前数据上限，单位为字节;约等于9.53M
  app.setImageCacheCount(100);//设置内存中缓存解码后图片的数量上限
}
1.
2.
3.
4.

demo 如下：

import app, { AppResponse } from '@system.app'
@Entry
@Component
export struct Index {
  @State private arr: number[] = [0, 1, 2, 3, 4, 5, 6]
  @State dragItem: number = -1
  @State scaleItem: number = -1
  @State neighborItem: number = -1
  @State neighborScale: number = -1
  private dragRefOffset: number = 0
  @State offsetY: number = 0
  private ITEM_INTV: number = 120
  aboutToAppear(): void {
    app.setImageRawDataCacheSize(1024*1024*100);//缓存 解码前数据上限，单位为字节;约等于9.53M
    app.setImageCacheCount(100);//设置内存中缓存解码后图片的数量上限
  }
  build() {
    List() {
      ForEach(this.arr, (item: number, index: number) => {
        ListItem() {
          this.buildItem(item)
        }
      }, (item: number) => item.toString())
    }
    .onClick(() => {
      let data = this.arr.splice(4, 1)[0]
      this.arr.splice(3, 0, data)
    })
  }

  @Builder
  buildItem(item: number) {
    Row() {
      Image($r('app.media.app_icon'))
        .width(18)
        .height(18).syncLoad(true).syncLoad(true)
      Text('你好你好' + item)
        .fontSize(16)
        .fontWeight(FontWeight.Medium)
        .fontColor('#323232')
        .margin({ left: 12 })
      Blank()

      Row() {
        Image($r('app.media.app_icon'))
          .height(18)
          .width(18)
          .autoResize(true).syncLoad(true)
      }
      .width(30)
      .height('100%')
      .alignItems(VerticalAlign.Center)
      .justifyContent(FlexAlign.Center)
      Row() {
        Image($r('app.media.app_icon'))
          .height(25)
          .width(25)
          .autoResize(true)
      }
      .height('100%')
      .width(50)
      .margin({ left: 30 })
      .justifyContent(FlexAlign.End)
      .alignItems(VerticalAlign.Center)
    }
    .padding({left: 15, right: 15})
    .width('100%')
    .height(50)
    .animation({ curve: Curve.Sharp, duration: 300 })
    .backgroundColor(0xFFFFFF)
    .justifyContent(FlexAlign.SpaceBetween)
  }
}
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.