• uniapp canvas画多个海报并保存到系统相册


    方法比较鸡肋,但好在能用,要求不高

    <template>
    <view>
    <swiper class="swiper" :style="'height:'+imgheight+'px;'+imgwidth+'px'" :indicator-dots="indicatorDots" :autoplay="autoplay" :interval="interval" :duration="duration" @change="currentposer">
    <block v-if="len==1">
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster1"></canvas>
    </swiper-item>
    </block>
    <block v-else-if="len==2">
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster1"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster2"></canvas>
    </swiper-item>
    </block>
    <block v-else-if="len==3">
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster1"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster2"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster3"></canvas>
    </swiper-item>
    </block>
    <block v-else-if="len==4">
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster1"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster2"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster3"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster4"></canvas>
    </swiper-item>
    </block>
    <block v-else-if="len==5">
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster1"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster2"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster3"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster4"></canvas>
    </swiper-item>
    <swiper-item>
    <canvas :style="'height:'+imgheight+'px;'+imgwidth+'px'" class="canvas" canvas-id="poster5"></canvas>
    </swiper-item>
    </block>
    </swiper>
    <view class="download f30" @click="download" v-if="cansave">保存图片</view>
    </view>
    </template>
    <script>
    import request from "../../static/common/common.js"
    export default {
    data() {
    return {
    invitation_codeVal:'',
    imgheight:'',
    img'',
    qrcode:'',
    filePath:'', //当前要保存的海报
    indicatorDots: false,
    autoplay: false,
    interval: 2000,
    duration: 500,
    imgUrlArr:[],
    len:'',
    currentnum:1,
    imgstartheight:'',
    cansave:false
    }
    },
    methods: {
    currentposer(e){
    var that = this;
    let num = Number(e.detail.current+1);
    that.currentnum = num;
    },
    // 获取海报背景图列表
    getposter(){
    var that = this;
    request.httpRequest({
    url:'api/index/poster'
    }).then(res=>{
    that.imgUrlArr = res.data.data.list;
    that.qrcode = res.data.data.qrcode;
    var len = res.data.data.list.length;
    that.len = len;
    if(len==0){
    uni.showToast({
    title:"暂无海报~",
    icon:"none",
    duration:2000
    });
    }else if(len==1){
    that.mapping(1);
    }else if(len==2){
    that.mapping(1);
    setTimeout(function(){
    that.mapping(2);
    },1000);
    }else if(len==3){
    that.mapping(1);
    setTimeout(function(){
    that.mapping(2);
    },1000);
    setTimeout(function(){
    that.mapping(3);
    },1000);
    }else if(len==4){
    that.mapping(1);
    setTimeout(function(){
    that.mapping(2);
    },1000);
    setTimeout(function(){
    that.mapping(3);
    },1000);
    setTimeout(function(){
    that.mapping(4);
    },1000);
    }else{
    that.mapping(1);
    setTimeout(function(){
    that.mapping(2);
    },1000);
    setTimeout(function(){
    that.mapping(3);
    },1000);
    setTimeout(function(){
    that.mapping(4);
    },1000);
    setTimeout(function(){
    that.mapping(5);
    },1000);
    }
    });
    },
    // 绘制海报
    mapping(num){
    var that = this;
    let ctx = uni.createCanvasContext('poster'+num);
    ctx.fillStyle = "#007AFF";
    let index = num -1;
    uni.getImageInfo({
    src:that.imgUrlArr[index].image,
    success(res) {
    ctx.drawImage(res.path, that.imgwidth*0.15/2, 12, that.imgwidth*0.85, that.imgheight*0.85);//绘制背景图
    uni.getImageInfo({
    src:that.qrcode,
    success(res2) {
    ctx.drawImage(res2.path, that.imgwidth*0.85-65, that.imgheight*0.85-90, 80,80);//绘制二维码
    ctx.setFillStyle('#FFFFFF')//文字颜色:默认黑色
    ctx.setFontSize(12)//设置字体大小,默认10
    ctx.textAlign = 'center' // 设置位置
    ctx.font = 'normal 12px sans-serif'; // 字体样式
    ctx.fillText("邀请码:"+that.invitation_codeVal,that.imgwidth*0.85-24, that.imgheight*0.85-100);
    setTimeout(function(){
    ctx.draw();
    uni.hideLoading();
    that.cansave = true;
    },2000);
    }
    });
    }
    });
    },
    // 保存图片
    download(){
    var that = this;
    uni.showLoading({
    title: '正在保存...',
    mask:true
    });
    uni.canvasToTempFilePath({
    canvasId: 'poster'+that.currentnum,
    // x: 0,
    // y: that.imgstartheight,
    // fileType: 'jpg',
    // that.imgwidth,
    // height: that.imgheight,
    // destWidth: that.imgwidth, // 如果保存到手机比较模糊 改这里 一般*2 即可解决
    // destHeight: that.imgheight, // 如果保存到手机比较模糊 改这里 一般*2 即可解决
    // quality:1,
    success: (res) => {
    uni.hideLoading();
    that.savepic(res.tempFilePath);
    },
    fail(err) {
    uni.hideLoading();
    },
    complete(com) {
    uni.hideLoading();
    }
    });
    },
    savepic(filePath){
    uni.saveImageToPhotosAlbum({
    filePath: filePath,
    success: function(response) {
    uni.showToast({
    title: '图片保存成功~'
    });
    },
    fail: function(err) {
    uni.showToast({
    title: '图片保存失败~'
    });
    },
    complete: function(com) {
    uni.hideLoading();
    }
    });
    }
    },
    onLoad(options) {
    var that = this;
    that.invitation_codeVal = options.invitation_codeVal;
    uni.showLoading({
    title:"海报生成中....",
    mask:true
    });
    uni.getSystemInfo({
    success(res) {
    that.imgwidth = res.windowWidth;
    that.imgheight = res.windowHeight;
    // 图片绘图高度位置
    let imgstartheight = Math.floor(res.windowHeight*0.06);
    that.imgstartheight = imgstartheight-2*imgstartheight;
    }
    });
    that.getposter();
    },
    }
    </script>
    <style lang="less" scoped>
    .code{
    position: absolute;
    bottom:50rpx;
    right: 50rpx;
    }
    .image_icon{
    100%;
    height: 800rpx;
    }
    .swiper{
    text-align: center;
    }
    .download{
    200rpx;
    border-radius: 50rpx;
    text-align: center;
    background-color: #BAAE98;
    padding: 20rpx;
    box-shadow: 0rpx 8rpx 8rpx rgba(0, 0, 0, 0.25);
    color: #FFFFFF;
    position: absolute;
    transform: translate(-50%,-50%);
    left: 50%;
    bottom: 10rpx;
    }
    </style>

    效果如图:

     

    ..
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  • 原文地址:https://www.cnblogs.com/shoolnight/p/15384645.html
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