h5基于cropper实现上传图片裁剪功能

基于cropper实现上传图片裁剪功能，保存原始图片尺寸分辨率，具体代码如下：
<!DOCTYPE html>
<html>
<head>
    <meta charset='UTF-8' />
    <meta name="viewport" content="initial-scale=1, width=device-width, maximum-scale=1, user-scalable=no">
    <meta name="wap-font-scale" content="no">
    <meta name="format-detection" content="telephone=no" />
    <title>66</title>

     <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.5.1/jquery.js"></script>
    <link rel="stylesheet" href="https://www.tpxhm.com/fdetail/item_content.css?16">
    <link href="https://cdn.bootcss.com/cropper/3.1.3/cropper.min.css" rel="stylesheet">
    <script src="https://cdn.bootcss.com/cropper/3.1.3/cropper.min.js"></script>

</head>
<body>
 <div class="button2" style="left: 1rem!important;">
    <button type="button" class="replace" onclick="document.getElementById('file').click()">替换封面</button>
        <input type="file" name="file" id="file" accept="image/*" style="display:none;">
</div>

<!-- 蒙层 -->
<div id="mask3" style="background-color:#000000;display: none;"></div>
<!-- 模态框 -->
<div id="model3" style="display: none;">
	<img src="https://www.tpxhm.com/fdetail/683.html" alt="" id="photo" style="width: 100%;height: auto;">
	<button style="position: absolute;left: 20%;width:6rem;height: 2.4rem;bottom: 5rem;border-radius:5px;border:0; font-size:1.2rem; color:#fff; background:#3eb5f3" id="clipImg">确定</button>
	<button style="position: absolute;right: 20%;width:6rem;height: 2.4rem;bottom: 5rem;border-radius:5px;border:0;background-color: #ffffff; color:#333;font-size:1.2rem" onclick="cancel_model3()">取消</button>
</div>

<script type="text/javascript">
    function cancel_model3(){
        $('#mask3').css("display",'none');
        $('#model3').css("display",'none');
    }

    $("#clipImg").on("click", function(){
        var cas=$("#photo").cropper('getCroppedCanvas');
        var base64url=cas.toDataURL('image/jpeg');
        console.log(base64url); //生成base64图片的格式
        
    });

</script>
<script>

    function submitMessage(){
        $('#mask').css("display",'none')
        $('#model').css("display",'none')
    }
    
    function replaceBackground(){
        $('#mask2').css("display",'block');
        $('#model2').css("display",'block');
    }

    document.querySelector('#file').addEventListener('change', function(e) {
        var file = this.files[0];

        if(file.type.indexOf("image") == 0) {
            var reader = new FileReader();
            reader.readAsDataURL(file);
            reader.onload = function(e) {
                // 图片base64化
                var newUrl = this.result;
                //console.log(newUrl)
                $("#cover_img").attr("src", newUrl);
                $('#mask3').css("display",'block');
                $('#model3').css("display",'block');
                var options = {
                    aspectRatio: 350 / 350,
                    dragMode: 'move',
                    viewMode: 1,
                    cropBoxResizable: false,
                    preview: '.img-preview',
                }
                $("#photo")
                    .cropper('destroy') // 销毁旧的裁剪区域
                    .attr('src', newUrl) // 重新设置图片路径
                    .cropper(options) // 重新初始化裁剪区域
            };
        }
       
    }, false);
</script>



</body>
</html>
效果展示：
附件下载：https://qiniu.tpxhm.top/code/h5CanvasCropper.zip