在 C# 或 JavaScript 中将 DIV 内容转换为图像

convert DIV contents to Image in C# or JavaScript

本文关键字:转换 图像 DIV JavaScript 中将      更新时间:2023-09-26

我有一个DIV容器,里面有一些文本,背景图像,图像。我需要将整个DIV内容转换为图像并保存到本地文件夹中。请指导我如何使用 JavaScript 或 C# 将 Div 内容转换为图像。我在谷歌上搜索过,但没有得到正确的结果。请提供一些源代码..帮帮我。

由于您不想融合整个HTML页面,而是融合HTML的一部分,请参阅以下链接中p.campbell给出的答案以获得完美的解决方案。

使用 C# 将 HTML 控件(div 或表)转换为图像

其他答案可能提供捕获整个html网页到图像。如果您发现 p.campbell 的答案难以实现,请在网站中创建一个仅包含 Div 内容的 html 页面,并通过给定的其他答案将其捕获到图像中。

http://html2canvas.hertzen.com/就是你要找的。用法:

.HTML:

<head>
    <title>Example of capturing the div</title>
</head>
<body>
    <div id="pictureMe"><p>Try this out on JSFiddle right now.</p></div>
    <script src="js/html2canvas.js" type="text/css" rel="stylesheet"></script>
    <script type="text/javascript">
            html2canvas(document.getElementByID("pictureMe"), {
            onrendered: function(canvas) {
            /* What you want to do with the screenshot goes here */
            document.body.appendChild(canvas);
            }
        });
    </script>
</body>

http://jsfiddle.net/fG4fY/现已推出。

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <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>
    <script type="text/javascript">
        function ConvertToCanvas(btnExporttoimage) {
            html2canvas($("#ContentInfo")[0]).then(function (canvas) {
                var base64 = canvas.toDataURL();
                $("[id*=hdnImageData]").val(base64);
                __doPostBack(btnExporttoimage.name, "");
            });
            return false;
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div id="ContentInfo" runat="server" style="width: 600px; background-color: White;
        padding: 5px; height: 600px;">
        <u>Student Info</u>
        <br />
        <br />
        <table>
            <tr>
                <td>
                    ID
                </td>
                <td>
                    Name
                </td>
                <td>
                    Country
                </td>
                <td class="style1">
                    Roll.
                </td>
            </tr>
            <tr>
                <td>
                    1
                </td>
                <td>
                    Ranjit
                </td>
                <td>
                    India
                </td>
                <td class="style1">
                    2345
                </td>
            </tr>
            <tr>
                <td>
                    2
                </td>
                <td>
                    Soumya
                </td>
                <td>
                    India
                </td>
                <td class="style1">
                    5678
                </td>
            </tr>
            <tr>
                <td>
                    3
                </td>
                <td>
                    Tapan
                </td>
                <td>
                    Srilanka
                </td>
                <td class="style1">
                    7890
                </td>
            </tr>
            <tr>
                <td>
                    4
                </td>
                <td>
                    Suresh
                </td>
                <td>
                    Bhutan
                </td>
                <td class="style1">
                    4345
                </td>
            </tr>
        </table>
    </div>
    <br />
    <asp:HiddenField ID="hdnImageData" runat="server" />
    <asp:Button ID="btnExporttoimage" Text="Export to Image" runat="server" UseSubmitBehavior="false"
        OnClientClick="return ConvertToCanvas(this)" OnClick="btnExporttoimage_Click" />
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Drawing.Imaging;
public override void VerifyRenderingInServerForm(Control control)
{
  /* Verifies that the control is rendered */
}
protected void btnExporttoimage_Click(object sender, EventArgs e)
{
    string base64 = Request.Form[hdnImageData.UniqueID].Split(',')[1];
    byte[] IMGbytes = Convert.FromBase64String(base64);
    ///////////-------FOLLOWING CODE IS TO CONVERT IMAGE TO BINARY AND TO DEFAULT DOWNLOAD PATH--------////////////////////  
    //Response.Clear();
    //Response.ContentType = "image/png";
    //Response.AddHeader("Content-Disposition","canvas.png"));
    //Response.Buffer = true;
    //Response.Cache.SetCacheability(HttpCacheability.NoCache);
    //Response.BinaryWrite(IMGbytes);
    //Response.End();

    ///////////-------FOLLOWING CODE IS TO CONVERT IMAGE TO BINARY AND TO DESIRE DOWNLOAD PATH--------////////////////////  
    MemoryStream msImage = new MemoryStream(IMGbytes, 0, IMGbytes.Length);
    msImage.Write(IMGbytes, 0, IMGbytes.Length);
    System.Drawing.Image imageTosave = System.Drawing.Image.FromStream(msImage, true);
    string filePath = Path.Combine(Server.MapPath("~/CanvasImages/"), "canvas.png");
    imageTosave.Save(filePath, ImageFormat.Png);
}
<head runat="server">
    <script type="text/javascript" src="html2canvas.min.js"></script>
    <style type="text/css">
        .labans {
            /*  color:#990000;*/
            color: #336600;
            font-family: Verdana;
            font-size: 14px;
            font-weight: 600;
            text-align: center;
        }
        .labans1 {
            /*  color:#990000;*/
            color: #000000;
            font-family: Verdana;
            font-size: 12px;
            font-weight: 600;
        }

        .divsection {
            border: 1px solid #DDD;
            padding: 8px 15px;
            spacing: 2px;
            border-radius: 8px;
            box-shadow: #EEEEEE 0.4em 0.0em 0.2em;
            background-image: url(../Images/Front.jpg);
            height: 15cm;
            width: 9.5cm;
            background-size: 358px;
            background-position: center top;
            background-repeat: no-repeat;
            object-fit: fill;
        }
    </style>
    <title></title>
    <!--ForExport data in iamge -->
    <script type="text/javascript">
        function ConvertToImage(btnExport) {
            html2canvas($("#dvContent")[0]).then(function (canvas) {
                var base64 = canvas.toDataURL();
                $("[id*=hfImageData]").val(base64);
                __doPostBack(btnExport.name, "");
            });
            return false;
        }
    </script>
    <!--ForExport data in iamge -->
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script src="../data/assets/js/html2canvas.min.js"></script>
</head>
<body>
    <form id="form1" runat="server">
        <div class="row" id="divhiddenInfo" runat="server" style="display: none">
            <div class="col-lg-2">
                <asp:HiddenField ID="lblCode" runat="server" />
            </div>
        </div>
        <asp:Button ID="btnDownload" Text="Download Front" runat="server" UseSubmitBehavior="false"
            OnClick="DownloadImage" OnClientClick="return ConvertToImage(this)" />
        <div id="dvContent" class="divsection">
            <asp:HiddenField ID="hfImageData" runat="server" />
            <table width="100%">
                <tr>
                    <td valign="Right">
                        <table width="88%">
                            <tr>
                                <td class="style43">
                                    <br />
                                    <asp:Image ID="Image1" runat="server" Height="155px" Width="129px" ImageAlign="Right" />
                                </td>
                            </tr>
                            <tr>
                                <td>
                                    <asp:Label ID="lblDegs" runat="server" CssClass="labans"></asp:Label>
                                </td>
                            </tr>
                            <tr>
                                <td>
                                    <asp:Label ID="lblCity" runat="server" CssClass="labans"></asp:Label>
                                </td>
                            </tr>
                            <tr>
                                <td>
                                    <asp:Label ID="lbllocation" runat="server" CssClass="labans"></asp:Label>
                                </td>
                            </tr>
                        </table>
                    </td>
                </tr>

            </table>
        </div>
    </form>
</body>

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

protected void DownloadImage(object sender, EventArgs e)
    {
        string base64 = Request.Form[hfImageData.UniqueID].Split(',')[1];
        byte[] bytes = Convert.FromBase64String(base64);
        Response.Clear();
        Response.ContentType = "image/jpeg";
        Response.AddHeader("Content-Disposition", "attachment; filename=Front.jpeg");
        Response.Buffer = true;
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        Response.BinaryWrite(bytes);
        Response.End();
    }