vue canvas 手绘进度条动画

2020-12-08  本文已影响0人  代码锋

vue+canvas 手绘进度条动画(不喜勿喷)

明确步骤

1.划一个矩形,加上文字效果

2.判断新值和现有值大小比较,并算出一份占矩形的长度

3.画图

直接上代码

<template>
    <div id="index" class="index">
        <canvas id="canvas"></canvas>
        <br />
        总值
        <el-input
            v-model="total"
            style="width:100px"
            placeholder="请输入内容"
        ></el-input>
        输入值
        <el-input
            v-model="now"
            :max="total"
            style="width:100px"
            placeholder="请输入内容"
        ></el-input>
        <el-button type="primary" @click="btnClick">主要按钮</el-button>
    </div>
</template>

<script>
export default {
    props: {
        // 父辈向子辈传参
    },
    name: "index",
    data() {
        return {
            cvs: "", //画布
            ctx: {},
            total: 200, //总数
            now: "", //现数
            oldNumber: 0, //老值
            newNumber: 0, //新值
            proportion: "", //占比,
        };
    },
    created() {
        // 实例被创建之后执行代码
    },
    computed: {
        // 计算属性
    },
    components: {
        // 组件的引用
    },
    methods: {
        // 方法
        btnClick() {
            this.proportion =
                (Number(this.now) / Number(this.total)) * Number(this.cvs.width); //比例:一份占多长
            this.newNumber = this.now;
            if (this.newNumber > this.total) {
                console.warn("超了");
            } else {
                if (Number(this.newNumber) > Number(this.oldNumber)) {
                    this.drivingChange(
                        Number(this.oldNumber),
                        Number(this.newNumber),
                        Number(this.now) / Number(this.total),
                        "++"
                    );
                    //增加
                } else if (Number(this.newNumber) < Number(this.oldNumber)) {
                    //减少
                    this.drivingChange(
                        Number(this.oldNumber),
                        Number(this.newNumber),
                        Number(this.now) / Number(this.total),
                        "--"
                    );
                } else {
                    console.warn("无变化");
                }
            }
        },
        drivingChange(oldVal, newVal, proportion, type) {
            //驱动改变(旧值,新值,百分比,加还是减方式)
            // console.warn(oldVal, newVal);
            var ss = oldVal;
            var that = this;
            var timer = setInterval(function() {
                that.clearRect();
                if (type == "++") {
                    that.dram(ss++, proportion);
                    if (ss > newVal) {
                        clearInterval(timer);
                    }
                } else {
                    that.dram(ss--, proportion);
                    if (ss < newVal) {
                        clearInterval(timer);
                    }
                }
            }, 10);
            this.oldNumber = newVal;
        },
        dram(i, proportion) {
            //画图
            this.ctx.fillStyle = "#7fecc1";
            /*矩形填充方法:fillRect(x,y,w,h)*/
            this.ctx.fillRect(51, 51, i - 2, 58); //i-2是为了去除掉边框空隙的
            this.ctx.fillStyle = "white";
            this.ctx.textAlign = "center";
            this.ctx.textBaseline = "middle";
            this.ctx.font = "26px 黑体";
            this.ctx.fillText(i, 120, 70);
            this.ctx.font = "16px 黑体";
            this.ctx.fillText("基础**", 120, 95);
            this.ctx.font = "30px 黑体";
            this.ctx.fillText(proportion * 100 + "%", 200, 80);
        },
        clearRect() {
            /*清理矩形方法:clearRect(x,y,w,h)*/
            this.ctx.clearRect(50, 50, 200, 60);
        },
        initCanvas() {
            //加载并绘制模型
            this.cvs = document.getElementById("canvas");
            //设置长宽
            this.cvs.width = 400;
            this.cvs.height = 400;
            //获取画笔
            this.ctx = this.cvs.getContext("2d");
            //===============================填充矩形方法
            /*填充矩形方法:fillRect(x,y,w,h)*/
            this.ctx.fillStyle = "#7fecc1";
            //===============================填充矩形方法

            //===============================描边矩形
            /*描边矩形方法:strokeRect(x,y,w,h)*/
            this.ctx.strokeStyle = "#7fecc1";
            this.ctx.lineWidth = 5;
            this.ctx.strokeRect(50, 50, 200, 60);
            //===============================描边矩形

            //===============================文字
            this.ctx.fillStyle = "white";
            this.ctx.textAlign = "center";
            this.ctx.textBaseline = "middle";
            this.ctx.font = "26px 黑体";
            this.ctx.fillText("00", 120, 70);
            this.ctx.font = "16px 黑体";
            this.ctx.fillText("基础**", 120, 95);
            this.ctx.font = "30px 黑体";
            this.ctx.fillText("00%", 200, 80);
            //===============================文字
        },
    },
    mounted() {
        // 页面进入时加载内容
        this.initCanvas();
    },
    watch: {
        // 监测变化
    },
};
</script>
<style scoped lang="scss">
#canvas {
    background-color: antiquewhite;
}
</style>

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