<input class="selectImg" style="position:absolute;opacity: 0;width:100px;height:100px;" type="file" name="coverChart" onchange="showImg(this)">

// 图片预览

function showImg(obj) {

    $(".doShow").css("background-image", "url('" + getObjectURL(obj.files[0]) + "')");

}

// 不同浏览器获得图片url

function getObjectURL(file) {

    var url = null;

    if (window.createObjectURL != undefined) {

        url = window.createObjectURL(file) ;

    } else if (window.URL != undefined) {

        url = window.URL.createObjectURL(file) ;

    } else if (window.webkitURL != undefined) {

        url = window.webkitURL.createObjectURL(file) ;

    }

    return url;

}