网站建设总体规划包括哪些,济南成之运维网络科技,郑州影视公司有哪些,saas系统怎么读ArkTS卡片开放了自定义绘制的能力#xff0c;在卡片上可以通过Canvas组件创建一块画布#xff0c;然后通过CanvasRenderingContext2D对象在画布上进行自定义图形的绘制#xff0c;如下示例代码实现了在画布的中心绘制了一个笑脸。 
Entry
Component
struct Card {
private c…ArkTS卡片开放了自定义绘制的能力在卡片上可以通过Canvas组件创建一块画布然后通过CanvasRenderingContext2D对象在画布上进行自定义图形的绘制如下示例代码实现了在画布的中心绘制了一个笑脸。 
Entry
Component
struct Card {
private canvasWidth: number  0;
private canvasHeight: number  0;
// 初始化CanvasRenderingContext2D和RenderingContextSettings
private settings: RenderingContextSettings  new RenderingContextSettings(true);
private context: CanvasRenderingContext2D  new CanvasRenderingContext2D(this.settings);build() {
Column() {
Row() {
Canvas(this.context)
.margin(5%)
.width(90%)
.height(90%)
.onReady(()  {
console.info([ArkTSCard] onReady for canvas draw content);
// 在onReady回调中获取画布的实际宽和高
this.canvasWidth  this.context.width;
this.canvasHeight  this.context.height;
// 绘制画布的背景
this.context.fillStyle  rgba(203, 154, 126, 1.00);
this.context.fillRect(0, 0, this.canvasWidth, this.canvasHeight);
// 在画布的中心绘制一个红色的圆
this.context.beginPath();
let radius  this.context.width / 3
let circleX  this.context.width / 2
let circleY  this.context.height / 2
this.context.moveTo(circleX - radius, circleY);
this.context.arc(circleX, circleY, radius, 2 * Math.PI, 0, true);
this.context.closePath();
this.context.fillStyle  red;
this.context.fill();
// 绘制笑脸的左眼
let leftR  radius / 4
let leftX  circleX - (radius / 2)
let leftY  circleY - (radius / 3.5)
this.context.beginPath();
this.context.arc(leftX, leftY, leftR, 0, Math.PI, true);
this.context.strokeStyle  #ffff00
this.context.lineWidth  10
this.context.stroke()
// 绘制笑脸的右眼
let rightR  radius / 4
let rightX  circleX  (radius / 2)
let rightY  circleY - (radius / 3.5)
this.context.beginPath();
this.context.arc(rightX, rightY, rightR, 0, Math.PI, true);
this.context.strokeStyle  #ffff00
this.context.lineWidth  10
this.context.stroke()
// 绘制笑脸的嘴巴
let mouthR  radius / 2.5
let mouthX  circleX
let mouthY  circleY  (radius / 3)
this.context.beginPath();
this.context.arc(mouthX, mouthY, mouthR, Math.PI, 0, true);
this.context.strokeStyle  #ffff00
this.context.lineWidth  10
this.context.stroke()
})
}
}.height(100%).width(100%)
}
}