問題描述

我喜歡在 div 上添加背景，僅適用于支持拖動 & 的瀏覽器.刪除文件

I like to add a background on a div only for browsers which support drag & drop for files

雖然我不喜歡使用modernizr，只是一個單行腳本

I don't like to use modernizr though, just a one line script

推薦答案

為什么不直接從 Modernizr 復制所需的部分?

Why not just copy required parts from Modernizr?

var isEventSupported = (function() {

      var TAGNAMES = {
        'select': 'input', 'change': 'input',
        'submit': 'form', 'reset': 'form',
        'error': 'img', 'load': 'img', 'abort': 'img'
      };

      function isEventSupported( eventName, element ) {

        element = element || document.createElement(TAGNAMES[eventName] || 'div');
        eventName = 'on' + eventName;

        // When using `setAttribute`, IE skips "unload", WebKit skips "unload" and "resize", whereas `in` "catches" those
        var isSupported = eventName in element;

        if ( !isSupported ) {
          // If it has no `setAttribute` (i.e. doesn't implement Node interface), try generic element
          if ( !element.setAttribute ) {
            element = document.createElement('div');
          }
          if ( element.setAttribute && element.removeAttribute ) {
            element.setAttribute(eventName, '');
            isSupported = typeof element[eventName] == 'function';

            // If property was created, "remove it" (by setting value to `undefined`)
            if ( typeof element[eventName] != 'undefined' ) {
              element[eventName] = undefined;
            }
            element.removeAttribute(eventName);
          }
        }

        element = null;
        return isSupported;
      }
      return isEventSupported;
    })();

用法:

if (isEventSupported('dragstart') && isEventSupported('drop')) {
  ...
}

對于文件 API:

var isFileAPIEnabled = function() {
  return !!window.FileReader;
};

這篇關于如何檢測瀏覽器支持文件 API 拖放的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！