移动端下载图片javascript js 下载图片

function getimg() //另存为存放在服务器上图片到本地的方法
    {
        event.returnValue = false;
        show.window.location.href = imgSrc.src; //$("#winShowPhoto > img")[0].src;        timer = setInterval(checkload, 100)
    }    function checkload()
    {
        if (show.readyState != "complete")
        {
            //调用document.execCommand方法，'Saveas'表示打开文件另存为对话框命令只有IE试用
            show.document.execCommand('Saveas');
            clearInterval(timer)
        }
    }
    function Download()
    {
        //cavas 保存图片到本地  js 实现
        //------------------------------------------------------------------------
        //1.确定图片的类型  获取到的图片格式 data:image/Png;base64,...... 
        var type = 'png';//你想要什么图片格式 就选什么吧
        var d = document.getElementById("imgSrc");        //$("#winShowPhoto > canvas")// currentSrc$("#winShowPhoto > img")[0]
        var imgdata = d.toDataURL(type);
        //2.0 将mime-type改为image/octet-stream,强制让浏览器下载
        var fixtype = function (type)
        {
            type = type.toLocaleLowerCase().replace(/jpg/i, 'jpeg');
            var r = type.match(/png|jpeg|bmp|gif/)[0];
            return 'image/' + r;
        };
        imgdata = imgdata.replace(fixtype(type), 'image/octet-stream');
        //3.0 将图片保存到本地
        var savaFile = function (data, filename)
        {
            var save_link = document.createElementNS('http://www.w3.org/1999/xhtml', 'a');
            save_link.href = data;
            save_link.download = filename;
            var event = document.createEvent('MouseEvents');
            event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
            save_link.dispatchEvent(event);
        };
        var filename = '' + new Date().getSeconds() + '.' + type;
        //我想用当前秒是可以解决重名的问题了 不行你就换成毫秒
        savaFile(imgdata, filename);
    };
    /**
* 根据图片生成画布
*/
    function convertImageToCanvas(image)
    {
        var canvas = document.createElement("canvas");
        canvas.width = image.width;
        canvas.height = image.height;
        canvas.getContext("2d").drawImage(image, 0, 0);
        return canvas;
    }
    /**
     * 下载图片
     */
    function down()
    {
        var sampleImage = $("#winShowPhoto > img")[0];// document.getElementById("imgSrc"),
        canvas = convertImageToCanvas(sampleImage);
        url = canvas.toDataURL("image/png");//PNG格式
        //以下代码为下载此图片功能
        var triggerDownload = $("#tttt").attr("href", url).attr("download", "order-1111111111.png");
        triggerDownload[0].click();
        //    triggerDownload.remove();
    }