从剪贴板粘贴图片

function pasteEvent(event) {    event = event || window.event;    var theClipboardData = event.clipboardData || window.clipboardData;    if (theClipboardData) {var items = theClipboardData.items;for (var i = 0; i < items.length; ++i) {var item = theClipboardData.items[i];if (items[i].kind == 'file' && items[i].type == 'image/png') {var fileReader = new FileReader();fileReader.onloadend = function () {var d = this.result.substr( this.result.indexOf(',')+1);var img = document.createElement("img");img.src= "data:image/png;base64,"+d;document.body.appendChild(img);};fileReader.readAsDataURL(item.getAsFile());break;}}    }};