harmony 鸿蒙CanvasGradient

2025-06-12
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CanvasGradient

NOTE

This component is supported since API version 4. Updates will be marked with a superscript to indicate their earliest API version.

CanvasGradient provides a canvas gradient object.

addColorStop

addColorStop(offset: number, color: string): void

Adds a color stop for the CanvasGradient object based on the specified offset and gradient color.

Parameters

Name	Type	Description
offset	number	Relative position of the gradient stop along the gradient vector, represented by the ratio of the distance between the gradient stop and the start point to the total length. The value ranges from 0 to 1.
color	string	Gradient color to set.

Example

<!-- xxx.hml -->
<div>
  <canvas ref="canvas" style="width: 500px; height: 500px; background-color: #ffff00;"></canvas>
</div>

// xxx.js
export default {
    onShow() {
        const el = this.$refs.canvas;
        const ctx = el.getContext('2d');
        const gradient = ctx.createLinearGradient(50, 0, 300, 100);
        gradient.addColorStop(0.0, '#ff0000')
        gradient.addColorStop(0.5, '#ffffff')
        gradient.addColorStop(1.0, '#00ff00')
        ctx.fillStyle = gradient
        ctx.fillRect(0, 0, 300, 300)
    }
}

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