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  • 前端上传图片并显示

    <!DOCTYPE html>
    <html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <title>图片上传</title>
    </head>
    <body>
        <!-- 要将父布局的position设置为relative,父布局将无法包裹input -->
        <div style="position: relative;">
            <!--设置input的position为absolute,使其不按文档流排版,并设置其包裹整个布局 -->
            <!-- 设置opactity为0,使input变透明 -->
            <!-- 只接受jpg,gif和png格式 -->
            <input id="upload-input" style="position: absolute; top: 0; bottom: 0; left: 0;right: 0; opacity: 0;" type="file" accept="image/gif, image/jpg, image/png" onchange="showImg(this)" multiple />
            <!-- 自定义按钮效果 -->
            <div style="text-align: top">
                <span style="font-size: 12px;">上传文件:</span>
                <img id="upload" src="./upload.png" style=" 40px; height: 40px; vertical-align: middle;" />
            </div>
        </div>
        <div id="imgContainer" style="margin-top: 10px;"></div>
    </body>
    <script type="text/javascript">
        function showImg(obj) {
            var files = obj.files
            // document.getElementById("imgContainer").innerHTML = getImgsByUrl(files)
            getImgsByFileReader(document.getElementById("imgContainer"), files)
        }
    
        // 使用window.URL.createObjectURL(file)读取file实例并显示图片
        function getImgsByUrl(files) {
            var elements = ''
            for (var i = 0; i < files.length; i++) {
                var url = window.URL.createObjectURL(files[i])
                elements += "<img src='"+ url + "' style=' 40px; height: 40px; vertical-align: middle; margin-right: 5px;' />"
            }
            return elements
        }
    
        // 使用FileReader读取file实例并显示图片
        function getImgsByFileReader(el, files) {
            for (var i = 0; i < files.length; i++) {
                let img = document.createElement('img')
                img.setAttribute('style', ' 40px; height: 40px; vertical-align: middle; margin-right: 5px;')
                el.appendChild(img)
                var reader = new FileReader()
                reader.onload = function(e) {
                    img.src = e.target.result
                }
                reader.readAsDataURL(files[i]) 
            }
        }
    </script>
    </html>
    

      

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  • 原文地址:https://www.cnblogs.com/navysummer/p/12848749.html
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