浏览器h5新建文件 保存到本地（相当于浏览器写文件）

function doSave(value, type, name) {

        var blob;

        if (typeof window.Blob == "function") {

            blob = new Blob([value], {type: type});

        } else {

            var BlobBuilder = window.BlobBuilder || window.MozBlobBuilder || window.WebKitBlobBuilder || window.MSBlobBuilder;

            var bb = new BlobBuilder();

            bb.append(value);

            blob = bb.getBlob(type);

        }

        var URL = window.URL || window.webkitURL;

        var bloburl = URL.createObjectURL(blob);

        var anchor = document.createElement("a");

        if ('download' in anchor) {

            anchor.style.visibility = "hidden";

            anchor.href = bloburl;

            anchor.download = name;

            document.body.appendChild(anchor);

            var evt = document.createEvent("MouseEvents");

            evt.initEvent("click", true, true);

            anchor.dispatchEvent(evt);

            document.body.removeChild(anchor);

        } else if (navigator.msSaveBlob) {

            navigator.msSaveBlob(blob, name);

        } else {

            location.href = bloburl;

        }

    }

doSave("哈哈", "text/latex", "latLangDa.txt");