图片上传

<!DOCTYPE html>
<html >
  <head>
    <meta charset="UTF-8">
    <meta name="google" value="notranslate">


    <title>CodePen - WeUI-Uploader</title>
    
    
    
    
        <style>
      body{
  background-color: #efeff4;
}
    </style>

    
    
    
  </head>

  <body>

    <!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta id="viewport" name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
  <title>WeUI-Uploader</title>
  <link rel="stylesheet" href="https://res.wx.qq.com/open/libs/weui/0.3.0/weui.css" />
</head>
<body>
  <div class="container">
    <div class="weui_cells_title">上传</div>
    <div class="weui_cells weui_cells_form">
      <div class="weui_cell">
        <div class="weui_cell_bd weui_cell_primary">
          <div class="weui_uploader">
            <div class="weui_uploader_hd weui_cell">
              <div class="weui_cell_bd weui_cell_primary">图片上传</div>
              <div class="weui_cell_ft js_counter">0/6</div>
            </div>
            <div class="weui_uploader_bd">
              <ul class="weui_uploader_files">
                <!-- 预览图插入到这 -->
              </ul>
              <div class="weui_uploader_input_wrp">
                <input class="weui_uploader_input js_file" type="file" accept="image/jpg,image/jpeg,image/png,image/gif" multiple="">
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>
  <div class="weui_dialog_alert" style="display: none;">
    <div class="weui_mask"></div>
    <div class="weui_dialog">
      <div class="weui_dialog_hd"><strong class="weui_dialog_title">警告</strong></div>
      <div class="weui_dialog_bd">弹窗内容,告知当前页面信息等</div>
      <div class="weui_dialog_ft">
        <a href="javascript:;" class="weui_btn_dialog primary">确定</a>
      </div>
    </div>
  </div>
  <script src="https://cdn.bootcss.com/zepto/1.1.6/zepto.min.js"></script>
</body>
</html>
    
    
        <script>
      $.weui = {};
$.weui.alert = function(options){
    options = $.extend({title: '警告', text: '警告内容'}, options);
    var $alert = $('.weui_dialog_alert');
    $alert.find('.weui_dialog_title').text(options.title);
    $alert.find('.weui_dialog_bd').text(options.text);
    $alert.on('touchend click', '.weui_btn_dialog', function(){
        $alert.hide();
    });
    $alert.show();
};

$(function () {
    // 允许上传的图片类型
    var allowTypes = ['image/jpg', 'image/jpeg', 'image/png', 'image/gif'];
    // 1024KB,也就是 1MB
    var maxSize = 1024 * 1024;
    // 图片最大宽度
    var maxWidth = 300;
    // 最大上传图片数量
    var maxCount = 6;
    $('.js_file').on('change', function (event) {
        var files = event.target.files;

        // 如果没有选中文件,直接返回
        if (files.length === 0) {
            return;
        }

        for (var i = 0, len = files.length; i < len; i++) {
            var file = files[i];
            var reader = new FileReader();

            // 如果类型不在允许的类型范围内
            if (allowTypes.indexOf(file.type) === -1) {
                $.weui.alert({text: '该类型不允许上传'});
                continue;
            }

            if (file.size > maxSize) {
                $.weui.alert({text: '图片太大,不允许上传'});
                continue;
            }

            if ($('.weui_uploader_file').length >= maxCount) {
                $.weui.alert({text: '最多只能上传' + maxCount + '张图片'});
                return;
            }

            reader.onload = function (e) {
                var img = new Image();
                img.onload = function () {
                    // 不要超出最大宽度
                    var w = Math.min(maxWidth, img.width);
                    // 高度按比例计算
                    var h = img.height * (w / img.width);
                    var canvas = document.createElement('canvas');
                    var ctx = canvas.getContext('2d');
                    // 设置 canvas 的宽度和高度
                    canvas.width = w;
                    canvas.height = h;
                    ctx.drawImage(img, 0, 0, w, h);
                    var base64 = canvas.toDataURL('image/png');

                    // 插入到预览区
                    var $preview = $('<li class="weui_uploader_file weui_uploader_status" style="background-image:url(' + base64 + ')"><div class="weui_uploader_status_content">0%</div></li>');
                    $('.weui_uploader_files').append($preview);
                    var num = $('.weui_uploader_file').length;
                    $('.js_counter').text(num + '/' + maxCount);

                    // 然后假装在上传,可以post base64格式,也可以构造blob对象上传,也可以用微信JSSDK上传

                    var progress = 0;
                    function uploading() {
                        $preview.find('.weui_uploader_status_content').text(++progress + '%');
                        if (progress < 100) {
                            setTimeout(uploading, 30);
                        }
                        else {
                            // 如果是失败,塞一个失败图标
                            //$preview.find('.weui_uploader_status_content').html('<i class="weui_icon_warn"></i>');
                            $preview.removeClass('weui_uploader_status').find('.weui_uploader_status_content').remove();
                        }
                    }
                    setTimeout(uploading, 30);
                };

                img.src = e.target.result;
            };
            reader.readAsDataURL(file);
        }
    });
});
      //@ sourceURL=pen.js
    </script>

    
    
    
  </body>
</html>
 

长按图片识别图中二维码(或搜索微信公众号FrontEndStory)关注“前端那些事儿”,带你探索前端的奥秘。

图片上传_第1张图片


你可能感兴趣的:(图片)