效果图：

代码块：

@Entry
@Component
struct GaugePage {

  @Builder descriptionBuilder() {
    Text('优')
      .maxFontSize(30)
      .minFontSize(30)
      .fontColor("#fffa2a2d")
      .fontWeight(FontWeight.Medium)
      .width('100%')
      .height("100%")
      .textAlign(TextAlign.Center)
  }
  
  build() {
    Column() {
      Gauge({ value: 50}) {
        Column() {
          Text('50')
            .maxFontSize(80)
            .minFontSize(60)
            .fontWeight(FontWeight.Medium)
            .fontColor("#ff182431")
            .width('40%')
            .height('30%')
            .textAlign(TextAlign.Center)
            .margin({ top: '22.2%' })
            .textOverflow({ overflow: TextOverflow.Ellipsis })
            .maxLines(1)
          Text('空气质量')
            .maxFontSize("16.0fp")
            .minFontSize("10.0vp")
            .fontColor($r('sys.color.ohos_id_color_text_secondary'))
            .fontColor($r('sys.color.ohos_id_color_text_secondary'))
            .fontWeight(FontWeight.Regular)
            .width('67.4%')
            .height('9.5%')
            .textAlign(TextAlign.Center)
        }.width('100%').height('100%')
      }
      .startAngle(225)
      .endAngle(135)
      .colors(new LinearGradient([{ color: "#e84026", offset: 0 },
        { color: "#f7ce00", offset: 0.6 },
        { color: "#64bb5c", offset: 1 }]))
      .width('80%')
      .height('80%')
      .strokeWidth(18)
      .trackShadow({ radius: 7, offsetX: 7, offsetY: 7 })
      .description(this.descriptionBuilder)
      .padding(18)
    }.margin({ top: 40 }).width('100%').height('100%')
  }
}