Quick PDF Library, my companies PDF SDK, will help you to render PDF files. It's not freeware, but the license allows for royalty-free distribution of compiled apps that you build with it. Finding free / open source components for rendering PDF files is a little trickier than other basic PDF manipulation tasks because rendering PDF files can be quite difficult.
Here is some C# sample source code that shows you how to render the PDF in the picture box on your form.
private void Form1_Load(object sender, EventArgs e)
{
QuickPDFAX0718.PDFLibrary pdf = new QuickPDFAX0718.PDFLibrary();
qp.UnlockKey("......Licence Key......");
// Open PDF File
int Handle = qp.DAOpenFile("C:\\sample.pdf", null);
// Get Total Number of Pages in a PDF File
int PageCount = qp.DAGetPageCount(Handle);
int PageNo = 1;
// It will get Reference of page 1 from PDF file
int PageRefNo = qp.DAFindPage(Handle, PageNo);
// You can change this parameter for Zoom In/Zoom Out purpose
int Zoom = 76;
double pageWidth = qp.DAGetPageWidth(Handle, PageRefNo) / Zoom;
double pageHeight = qp.DAGetPageHeight(Handle, PageRefNo) / Zoom;
// DPI use for rendering the page. Increase DPI will increate quality of image
int dpi = 92;
// Calculate Dimension of final output image
Bitmap b = new Bitmap(Convert.ToInt32(pageWidth * dpi), Convert.ToInt32(pageHeight * dpi));
// This will Draw render image on GDI
using (Graphics g = Graphics.FromImage(b))
{
IntPtr dc = g.GetHdc();
qp.DARenderPageToDC(Handle, PageRefNo, dpi, (int)dc);
g.ReleaseHdc(dc);
}
// Assigne rendered image to PictureBox Control which will display PDF on Windows Form.
pictureBox1.Image = b;
pictureBox1.BorderStyle = BorderStyle.Fixed3D;
}
The library doesn't include built-in functions to help you with zooming, but since you're rendering the PDF as a BMP image you can take care of the zooming fairly easily.