canvas_26 画图像

<template>
    <view class="zcvs">

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

    </view>
</template>

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

            };
        },
        onReady() {
            this.drawCvs();
        },
        methods: {
            drawCvs() {

                // 画画布
                let pixList = [];
                for (let i = 0; i < 200; i++) {
                    pixList.push(...[234, 67, 53, 255])
                }
                const data = new Uint8ClampedArray(pixList);
                uni.canvasPutImageData({
                    canvasId: 'cvs',
                    x: 200,
                    y: 200,
                     pixList.length / 4,
                    data: data,
                    success(res) {
                        console.log("像素写入画布成功！");
                    }
                })

                // 读画布
                uni.canvasGetImageData({
                    canvasId: "cvs",
                    x: 200,
                    y: 200,
                     pixList.length / 4,
                    height: 1,
                    success(res) {
                        console.log(res.width) // 200
                        console.log(res.height) // 1
                        console.log(res.data instanceof Uint8ClampedArray) // true
                        console.log(res.data.length) // 200 * 1 * 4

                        let data = res.data;
                        for (var i = 0; i < data.length; i += 4) {
                            var red = data[i]; // red
                            var green = data[i + 1]; // green
                            var blue = data[i + 2]; // blue
                            // i+3 就是 alpha 值
                            console.log("颜色是：", red, green, blue);
                        }

                    }
                })
            },
        }
    }
</script>

<style lang="scss" scoped>

</style>