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xhs.arc

开发
>
JS API
>
画布
>
CanvasContext
>
arc
>
更新时间:2024-11-13 19:05:32

画一条弧线。

参数

属性
类型
默认值
必填
说明
最低版本
xNumber圆的 x 坐标
yNumber圆的 y 坐标
rNumber圆的半径
aAngleNumber起始弧度(单位:弧度),在 3 点钟方向)
eAngleNumber终止弧度
counterclockwiseBoolean指定弧度的方向是逆时针还是顺时针

示例代码

Page({
    onLoad() {
        const canvasContext = swan.createCanvasContext('myCanvas');
        canvasContext.arc(100, 75, 50, 0, 2 * Math.PI);
        canvasContext.setFillStyle('blue');
        canvasContext.fill();
        canvasContext.draw();
    }
});

Page({
    onLoad() {
        let canvasContext = swan.createCanvasContext('myCanvas');
        canvasContext.arc(100, 98, 40, 0, 2 * Math.PI);
        canvasContext.setFillStyle('blue');
        canvasContext.fill();
        canvasContext.setLineWidth(6);
        canvasContext.setStrokeStyle('#FFB7DD');
        canvasContext.setLineCap('round')
        canvasContext.beginPath();
        canvasContext.arc( 75, 65, 20, Math.PI * 0.75,  Math.PI * 1.85, false);
        canvasContext.arc( 115, 60, 20, Math.PI * 1.15,  Math.PI * 2.15, false);
        canvasContext.arc( 140, 90, 20, Math.PI * 1.55,  Math.PI * 2.45, false);
        canvasContext.arc( 125, 125, 20, Math.PI * 1.75,  Math.PI * 2.75, false);
        canvasContext.arc( 90, 135, 20, Math.PI * 2.15,  Math.PI * 3.15, false);
        canvasContext.arc( 60, 105, 20, Math.PI * 2.40,  Math.PI * 3.50, false);
        canvasContext.closePath();
        canvasContext.stroke();
        canvasContext.draw();
    }
});


Page({
    onLoad() {
        const canvasContext = swan.createCanvasContext('myCanvas');
        // counterclockwise 的可选值还有 false
        canvasContext.arc(100, 75, 50, 2, 2 * Math.PI, true);
        canvasContext.setFillStyle('blue');
        canvasContext.fill();
        canvasContext.draw();
    }
});

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