Question

我试过这样的

   protected void Page_Load(object sender, EventArgs e)
    {
        //saveURLToImage("http://localhost:2564/Pagetoimage.aspx?OrderId=7");
        saveURLToImage("http://www.w3schools.com/");

    }

    private void saveURLToImage(string url)
    {
        if (!string.IsNullOrEmpty(url))
        {
            string content = "";

            System.Net.WebRequest webRequest = WebRequest.Create(url);
            System.Net.WebResponse webResponse = webRequest.GetResponse();
            System.IO.StreamReader sr = new StreamReader(webResponse.GetResponseStream(), System.Text.Encoding.GetEncoding("UTF-8"));
            content = sr.ReadToEnd();
            //save to file
            byte[] b = Convert.FromBase64String(content);
            System.IO.MemoryStream ms = new System.IO.MemoryStream(b);
            System.Drawing.Image img = System.Drawing.Image.FromStream(ms);

            string folderPath = Server.MapPath("~/ImagesFolder/");  //Create a Folder in your Root directory on your solution.
            string fileName = "IMageName" + DateTime.Now.Year + DateTime.Now.Month + DateTime.Now.Day + DateTime.Now.Hour + DateTime.Now.Minute + DateTime.Now.Second + ".jpg";
            string imagePath = folderPath + fileName;
            img.Save(imagePath, System.Drawing.Imaging.ImageFormat.Jpeg);

            img.Dispose();
            ms.Close();
        }
    }

但是这个错误即将到来

输入不是有效的Base-64字符串，因为它包含非基数64 字符，两个以上的填充字符或非法字符在填充字符中。

请帮帮我。

Answer 1

你可以在这里使用画布。将此脚本添加到.aspx页面

<script type="text/javascript">
            function ConvertToImage(btnExport) {
                html2canvas($("selector")[0]).then(function (canvas) {
                    var base64 = canvas.toDataURL();
                    $("[id*=hfImageData]").val(base64);
                    __doPostBack(btnExport.name, "");
                });
                return false;
            }
</script>

并将你的功能改为像这样

            string base64 = Request.Form[hfImageData.UniqueID].Split(',')[1];
            byte[] bytes = Convert.FromBase64String(base64);
            System.IO.MemoryStream ms = new System.IO.MemoryStream(bytes);
            System.Drawing.Image img = System.Drawing.Image.FromStream(ms);
            string folderPath = Server.MapPath("~/Images/");  //Create a Folder in your Root directory on your solution.
            string fileName = "IMageName" + DateTime.Now.Year + DateTime.Now.Month + DateTime.Now.Day + DateTime.Now.Hour + DateTime.Now.Minute + DateTime.Now.Second + ".jpg";
            string imagePath = folderPath + fileName;
            img.Save(imagePath, System.Drawing.Imaging.ImageFormat.Png);

在页面上添加一个按钮，您必须单击该按钮调用此函数，并在客户端单击时调用ConvertToImage（）函数。并且还添加一个隐藏字段，如下所示： -

<asp:HiddenField ID="hfImageData" runat="server" />
<asp:Button ID="btnExport" Text="Export to Image" runat="server" UseSubmitBehavior="false"
    OnClick="saveURLToImage" OnClientClick="return ConvertToImage(this)" />

现在，当您单击按钮时，它将在指定的路径上保存服务器上的网页图像。并且您可以更改要捕获其图像的jquery选择器。此解决方案使用jquery和canvas来确保导入库。

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript" src="http://cdn.rawgit.com/niklasvh/html2canvas/master/dist/html2canvas.min.js"></script>

如何在asp.net中将页面转换为图像

1 个答案: