render pdf from memorystream

Question

I have searched for entire day for a solution, but somehow I couldn't find it. What I wanted is to get data from database (binary file such as PDF) into MemoryStream (which I succeeded to do so), but problem is when I wish to preview that file into WebBrowser control.

so the code goes:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.IO;

namespace MemoryStreamTest
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    MemoryStream memory = new MemoryStream();
    //byte[] temp;

    private void Form1_Load(object sender, EventArgs e)
    {
      memory = GetBlobFile();
    }
    private MemoryStream GetBlobFile()
    {
        MemoryStream ms = new MemoryStream();
        string SQL = "SELECT [SnapshotPDF] FROM [DBtest].[dbo].[SamplePDF] WHERE id = " + 21;
        SqlConnection conn = new SqlConnection("Data Source=database;Initial Catalog=DBtest; User ID=test; Password=test;");
        SqlCommand comm = new SqlCommand(SQL, conn);
        conn.Open();
        byte [] result = (byte[])comm.ExecuteScalar();
        conn.Close();
        if (result != null)
        {
            ms.Write(result, 0, result.Length);
            ms.Position = 0;
        }
        return ms;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        //webBrowser1.DocumentText = "application/pdf";
        webBrowser1.DocumentStream = memory; 
    }
}
}

Actually webBrowser really output content from memory, but obviously from picture above it's rendered as text... How can I force to render as PDF?

If it is not possible to use webBrowser control, is there any other controls that I can use in WinForms that would preview/render PDF from memory.

Answer 1

You have to implement an async pluggable protocol, e.g. IClassFactory, IInternetProtocol... Then you use CoInternetGetSession to register your protocol. When IE calls your implementation, you can serve your image data from memory/provide mime type.

It's a bit tedious, but doable. Look at IInternetProtocol and pluggable protocols documentation on MSDN.

Answer 2

Done, I found one little bug which I correct it. this is entire code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.IO;
using Ghostscript.NET;
using Ghostscript.NET.Viewer;

namespace MemoryStreamTest
{

public partial class Form1 : Form
{

    Stream stream;
    byte[] result;
    private GhostscriptViewer _viewer;
    private GhostscriptVersionInfo _gsVersion = GhostscriptVersionInfo.GetLastInstalledVersion();
    private Bitmap _pdfPage = null;

    public Form1()
    {
        InitializeComponent();
        pictureBox1.Width = 100;
        pictureBox1.Height = 100;
        _viewer = new GhostscriptViewer();
        _viewer.DisplaySize += new GhostscriptViewerViewEventHandler(_viewer_DisplaySize);
        _viewer.DisplayUpdate += new GhostscriptViewerViewEventHandler(_viewer_DisplayUpdate);
        _viewer.DisplayPage += new GhostscriptViewerViewEventHandler(_viewer_DisplayPage);
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        GetBlobFile();
    }
    private void GetBlobFile()
    {
        string SQL = "SELECT [SnapshotPDF] FROM [test].[dbo].[InvoiceAdded] WHERE id = " + 21;
        SqlConnection conn = new SqlConnection("Data Source=test;Initial Catalog=test; User ID=test; Password=test;");
        SqlCommand comm = new SqlCommand(SQL, conn);
        conn.Open();
        result = (byte[])comm.ExecuteScalar();
        conn.Close();
        stream = new MemoryStream(result);
    }

    private void button1_Click(object sender, EventArgs e)
    {
        ConvertToBitmap();
    }

    private void ConvertToBitmap()
    {
        _viewer.Open(stream, _gsVersion, true);    
    }
    //DisplayPage
    void _viewer_DisplayPage(object sender, GhostscriptViewerViewEventArgs e)
    {
        pictureBox1.Invalidate();
        pictureBox1.Update();
    }
    //DisplaySize - dynamically
    void _viewer_DisplaySize(object sender, GhostscriptViewerViewEventArgs e)
    {
        pictureBox1.Image = e.Image;
    }
    //DisplayUpdate - automatic update picture
    void _viewer_DisplayUpdate(object sender, GhostscriptViewerViewEventArgs e)
    {
        pictureBox1.Invalidate();
        pictureBox1.Update();
    }
}
}

keep in mind that for this I needed to add .dll from Ghostscript.NET (a nice wrapper made by my patriot from Croatia), also I needed to install Ghostscript interpreter from GhostScript interpreter

And also many thanks to user: sm.abdullah

which actually point me to right direction. Cheers