HarmonyOS Canvas设置渐变色没有效果

使用CanvasRenderingContext2D的createLinearGradient(0, 0, 5, 0)函数创建的渐变对象，这里面的参数没太明白是什么意思？我添加了两种渐变色，但是始终只显示一种颜色。

private settings: RenderingContextSettings = new RenderingContextSettings(true)
private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings)
//onReady 绘制进度片段

let grad = this.context.createLinearGradient(0, 0, 5, 0)
grad.addColorStop(0, '#FF4EE6FF')
grad.addColorStop(1, '#FFA48EFF')
this.context.strokeStyle = grad
this.context.lineWidth = 10
this.context.lineCap = "round"
this.context.beginPath();
this.context.arc(circleWidth, circleHeight, radius, -1.57, 0);
this.context.stroke();