canvas_25 椭圆

canvas_25 椭圆

<template>
    <view class="zcvs">

        <view class="zcvs-item">
            <view>椭圆</view>
            <view>
                <canvas canvas-id="cvs" id="cvs" style="width: 400px; height: 400px;border: 1px solid #007AFF;" />
            </view>
        </view>

    </view>
</template>

<script>
    export default {
        data() {
            return {

            };
        },
        onReady() {
            this.drawCvs();
        },
        methods: {
            drawCvs() {
                const ctx = uni.createCanvasContext('cvs');
                const centX = 0;
                const centY = 0;
                const cWidth = 400;
                const cHeight = 400;
                const radius = 50;

                ctx.save(); // 保存状态1
                ctx.translate(cWidth / 2, cHeight / 2); // 移动原点
                ctx.scale(2, 1); // 水平放大
                ctx.beginPath(); // 缩放之后画圆
                ctx.arc(centX, centY, radius, 0, 2 * Math.PI, false);
                ctx.setFillStyle("#007AFF");
                ctx.fill();

                ctx.restore(); // 还原
                ctx.arc(centX, centY, radius, 0, 2 * Math.PI, false);
                ctx.fill();

                ctx.draw();
            },
        }
    }
</script>

<style lang="scss" scoped>

</style>

 

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