Take a screenshot of an iFrame

问题

I am looking for a simple way to take a screenshot of an iFrame in my ASP page. I just couldn't achieve it with C# and I lack of knowledge of Javascript! Does anyone out there know the simple and best way to achieve this?

What I am trying to do is, I am building a website that students can log in to e-government website in my country and prove if they are continuing student with a single click so that they can get discount from our service.

Edit: The puzzle should be solved in local.

回答1:

this piece of code worked for me. I hope it does the same to the others.

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); 
            img.Save(@"c:\pic.jpg", System.Drawing.Imaging.ImageFormat.Jpeg); 


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

回答2:

Unless I'm misunderstanding you, this is impossible.

You cannot instruct the user's browser to take a screenshot (this would be a security risk … and has few uses cases anyway).
You cannot load the page you want a screenshot of yourself (with server side code) because you don't have the credentials needed to access it.

回答3:

server side Take a screenshot of a webpage with JavaScript?

javascript http://html2canvas.hertzen.com/

来源：https://stackoverflow.com/questions/9362620/take-a-screenshot-of-an-iframe

标签

javascript

ASP.NET

iframe