js保存图片（兼容ie）

使用window.navigator.userAgent获取浏览器你内核，然后判断是不是ie/edge内核

// 判断浏览器类型
function myBrowser() {
    var sBrowser = null
    var sUsrAg = window.navigator.userAgent
    if (sUsrAg.indexOf('Firefox') > -1) {
        sBrowser = 'FF'
    } else if (sUsrAg.indexOf('Opera') > -1 || sUsrAg.indexOf('OPR') > -1) {
        sBrowser = 'Opera'
    } else if (sUsrAg.indexOf('Trident') > -1) {
        sBrowser = 'IE'
    } else if (sUsrAg.indexOf('Edge') > -1) {
        sBrowser = 'Edge'
    } else if (sUsrAg.indexOf('Chrome') > -1) {
        sBrowser = 'Chrome'
    } else if (sUsrAg.indexOf('Safari') > -1) {
        sBrowser = 'Safari'
    } else {
        sBrowser = 'unknown'
    }
    return sBrowser
}

如果是ie/edge内核

// IE浏览器图片保存本地
function SaveAs5(url, fileName) {
    var bstr = atob(url.split(',')[1])
    var n = bstr.length
    var u8arr = new Uint8Array(n)
    while (n--) {
        u8arr[n] = bstr.charCodeAt(n)
    }
    var blob = new Blob([u8arr])
    window.navigator.msSaveOrOpenBlob(blob, fileName)
}

其他浏览器

// 谷歌，360极速等浏览器下载
function download(src, fileName) {
    var aLink = document.createElement('a');
    aLink.download = fileName;
    aLink.href = src 
    aLink.click();
};

完整js代码

// 下载前先判断浏览器的内核
function oDownLoad(url, fileName) {
    if (myBrowser() == "IE" || myBrowser() == "Edge") {
        SaveAs5(url, fileName);
    } else {
        download(url, fileName);
    }
}

// IE浏览器图片保存本地
function SaveAs5(url, fileName) {
    var bstr = atob(url.split(',')[1])
    var n = bstr.length
    var u8arr = new Uint8Array(n)
    while (n--) {
        u8arr[n] = bstr.charCodeAt(n)
    }
    var blob = new Blob([u8arr])
    window.navigator.msSaveOrOpenBlob(blob, fileName)
}

// 谷歌，360极速等浏览器下载
function download(src, fileName) {
    //需要转成blob，base64下载大图会超出href的限制，导致下载失败
    var aLink = document.createElement('a');
    aLink.download = fileName;
    // var blob = dataURLtoBlob(src);
    aLink.href = src // URL.createObjectURL(blob);
    aLink.click();
};

// 判断浏览器类型
function myBrowser() {
    var sBrowser = null
    var sUsrAg = window.navigator.userAgent
    if (sUsrAg.indexOf('Firefox') > -1) {
        sBrowser = 'FF'
    } else if (sUsrAg.indexOf('Opera') > -1 || sUsrAg.indexOf('OPR') > -1) {
        sBrowser = 'Opera'
    } else if (sUsrAg.indexOf('Trident') > -1) {
        sBrowser = 'IE'
    } else if (sUsrAg.indexOf('Edge') > -1) {
        sBrowser = 'Edge'
    } else if (sUsrAg.indexOf('Chrome') > -1) {
        sBrowser = 'Chrome'
    } else if (sUsrAg.indexOf('Safari') > -1) {
        sBrowser = 'Safari'
    } else {
        sBrowser = 'unknown'
    }
    return sBrowser
}

// 直接引用
oDownLoad(base64文件,'aa.jpg')

dataURLtoBlob 你们可能用不了，想其他方法转吧