Text怎么设置文本渐变？

@Entry  
@Component  
struct Index {  
  @State message: string = 'Hello World'  
  private settings: RenderingContextSettings = new RenderingContextSettings(true)  
  private context: CanvasRenderingContext2D= new CanvasRenderingContext2D(this.settings)  
  
  build() {  
    Row() {  
      Column() {  
        Text(this.message)  
          .fontSize(50)  
          .fontWeight(FontWeight.Bold)  
          .linearGradient({  
            direction: GradientDirection.Left, // 渐变方向  
            colors: [[0xf88b57, 0.0], [0xaee4a0, 0.4], [0xc4d1ec, 0.7], [0xc08dcc, 0.9]] // 数组末尾元素占比小于1时满足重复着色效果  
          })  
        Canvas(this.context)  
          .onReady(() =>{  
            //绘制填充类文本  
            var grad = this.context.createLinearGradient(50,0, 300,100)  
            grad.addColorStop(0.0, '#f88b57')  
            grad.addColorStop(0.4, '#aee4a0')  
            grad.addColorStop(0.7, '#c4d1ec')  
            grad.addColorStop(0.9, '#c08dcc')  
            this.context.fillStyle = grad  
            this.context.font = '147px sans-serif';  
            this.context.fillText("Hello World!", 45, 100);  
          })  
      }  
      .width('100%')  
    }  
    .height('100%')  
  }  
}