Here's a sample that converts Text in TextBox to image same way you will have to set runat="server" to DIV and then get its content using div.InnerHtml
HTML
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<asp:TextBox runat = "server" ID = "txtText"></asp:TextBox>
<asp:Button ID = "btnConvert" runat = "server" Text = "Convert"
onclick="btnConvert_Click" />
<hr />
<asp:Image ID = "imgText" runat = "server" Visible = "false" />
</form>
</body>
</html>
Namespaces
using System.Drawing.Drawing2D;
using System.IO;
using System.Drawing.Imaging;
Code
protected void btnConvert_Click(object sender, EventArgs e)
{
string text = txtText.Text.Trim();
Bitmap bitmap = new Bitmap(1, 1);
Font font = new Font("Arial", 25, FontStyle.Regular, GraphicsUnit.Pixel);
Graphics graphics = Graphics.FromImage(bitmap);
int width = (int)graphics.MeasureString(text, font).Width;
int height = (int)graphics.MeasureString(text, font).Height;
bitmap = new Bitmap(bitmap, new Size(width, height));
graphics = Graphics.FromImage(bitmap);
graphics.Clear(Color.White);
graphics.SmoothingMode = SmoothingMode.AntiAlias;
graphics.TextRenderingHint = TextRenderingHint.AntiAlias;
graphics.DrawString(text, font, new SolidBrush(Color.FromArgb(255, 0, 0)), 0, 0);
graphics.Flush();
string fileName = Path.GetFileNameWithoutExtension(Path.GetRandomFileName()) + ".jpg";
bitmap.Save(Server.MapPath("~/images/") + fileName, ImageFormat.Jpeg);
imgText.ImageUrl = "~/images/" + fileName;
imgText.Visible = true;
}
