js实现ctrl+v粘贴图片

<div id="textareaBox" style="width: 500px;height: 300px; border: 1px solid #dcdcdc" contenteditable="true"></div>

document.getElementById("textareaBox").addEventListener('paste', function (e) {
    var that = this,ev = e || event;
    if (ev.clipboardData || ev.originalEvent) {
        var clipboardData = (ev.clipboardData || ev.originalEvent.clipboardData);
        if (clipboardData.items) {
            var blob;
            for (var i = 0; i < clipboardData.items.length; i++) {
                if (clipboardData.items[i].type.indexOf("image") !== -1) {
                    blob = clipboardData.items[i].getAsFile();
                }
            }
            var render = new FileReader();
            render.onload = function (evt) {
                //输出base64编码
                var base64 = evt.target.result;
                var imgElem = document.createElement('img');
                var pElem = document.createElement('p');
                imgElem.src = base64;
                that.appendChild(pElem.appendChild(imgElem));
            };
            if (blob) {
                render.readAsDataURL(blob);
            }
        }
    }
});