HarmonyOS 鸿蒙Next CustomBuilder加载慢

自定义背景渲染会有一定延迟，不能响应事件，不能进行动态更新。该属性不支持嵌套使用，且不支持预览器预览。官方文档：背景设置-通用属性-组件通用信息-ArkTS组件-ArkUI（方舟UI框架）-应用框架 - 华为HarmonyOS开发者

你可以使用如你希望用图片作为背景，可以考虑使用backgroundImage来实现，参考：背景设置-通用属性-组件通用信息-ArkTS组件-ArkUI（方舟UI框架）-应用框架 - 华为HarmonyOS开发者

你可以通过通用属性borderImage实现,请参考：图片边框设置-通用属性-组件通用信息-ArkTS组件-ArkUI（方舟UI框架）-应用框架 - 华为HarmonyOS开发者

你可以根据实际情况调整相应参数，参考demo如下：

@Entry
@Component
struct BorderImage {
  @State WidthValue: number = 0
  @State SliceValue: number = 0
  @State OutSetValue: number = 0
  @State RepeatValue: RepeatMode[] = [RepeatMode.Repeat, RepeatMode.Stretch, RepeatMode.Round, RepeatMode.Space]
  @State SelectIndex: number = 0
  @State SelectText: string = 'Repeat'
  @State FillValue: boolean = false

  build() {

    Row {

      Column({ space: 20 }) {

        Row {

          Text('This is borderImage.').textAlign(TextAlign.Center).fontSize(50)

        }

        .borderImage({

          source: $r('app.media.app_icon'),
          slice: this.SliceValue,
          width: this.WidthValue,
          outset: this.OutSetValue,
          repeat: this.RepeatValue[this.SelectIndex],
          fill: this.FillValue

        })

        Column() {

          Text(`borderImageSlice = ${this.SliceValue}px`)

          Slider({
            value: this.SliceValue,
            min: 0,
            max: 100,
            style: SliderStyle.OutSet
          })
            .onChange((value: number, mode: SliderChangeMode) => {
              this.SliceValue = value
            })

        }

        Column() {

          Text(`borderImageWidth = ${this.WidthValue}px`)

          Slider({
            value: this.WidthValue,
            min: 0,
            max: 100,
            style: SliderStyle.OutSet
          })
            .onChange((value: number, mode: SliderChangeMode) => {
              this.WidthValue = value
            })

        }

        Column() {

          Text(`borderImageOutSet = ${this.OutSetValue}px`)

          Slider({
            value: this.OutSetValue,
            min: 0,
            max: 100,
            style: SliderStyle.OutSet
          })
            .onChange((value: number, mode: SliderChangeMode) => {
              this.OutSetValue = value
            })

        }

        Row() {

          Text('borderImageRepeat: ')

          Select([{ value: 'Repeat' }, { value: 'Stretch' }, { value: 'Round' }, { value: 'Space'}])
            .value(this.SelectText)
            .selected(this.SelectIndex)
            .onSelect((index: number, value?: string) => {
              this.SelectIndex = index
              this.SelectText = value as string
            })

        }

        Row() {

          Text(`borderImageFill: ${this.FillValue} `)

          Toggle({ type: ToggleType.Switch, isOn: this.FillValue })
            .onChange((isOn: boolean) => {
              this.FillValue = isOn
            })

        }

      }

      .width('100%')

    }

    .height('100%')

  }
}

详细参数解释参考官网链接：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/ts-universal-attributes-border-image-V5