We Keep Coding

Move dynamically created image to a new page

I can dynamically create a barcode using sample tutorials.
This block of code is in a loop and generates a number of images determined by user input. The image is in a place holder and is displayed on the same webpage.
I want the user to be able to have all the images on a separate page or file for them to print, but I'm not quite sure the best approach to do that. I tried placing it in a session, but I only get 1 image as opposed to the amount the user entered.
System.Web.UI.WebControls.Image imgBarCode = new System.Web.UI.WebControls.Image();
using (Bitmap bitMap = new Bitmap(barCode.Length * 27, 100))
{
using (Graphics graphics = Graphics.FromImage(bitMap))
{
Font oFont = new Font("IDAutomationHC39M", 16);
PointF point = new PointF(2f, .2f);
SolidBrush blackBrush = new SolidBrush(Color.Black);
SolidBrush whiteBrush = new SolidBrush(Color.White);
graphics.FillRectangle(whiteBrush, 0, 0, bitMap.Width, bitMap.Height);
graphics.DrawString("*" + barCode + "*", oFont, blackBrush, point);
}
using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
{
bitMap.Save(ms, ImageFormat.Png);
byte[] byteImage = ms.ToArray();
Convert.ToBase64String(byteImage);
imgBarCode.ImageUrl = "data:image/png;base64," + Convert.ToBase64String(byteImage);
}
plBarCode.Controls.Add(imgBarCode);
}

How to insert a dynamically generated bitmap into PDF document using PDFsharp?

I am trying to use PDFsharp to insert a dynamically generated bitmap of a QR Code in to a PDF document. I don't want to save the bitmap to the file but just want to insert it into the PDF. The problem I'm having is the DrawImage command is looking for a string where the image file is located. But I don't want to save the file, I just want to insert it into the PDF document. Is there a way of doing this?
var QRCode_BMP = _generalCode.QR_CodeGenerator(AddReviewPath); //This generates the bitmap
MemoryStream streamQR = new MemoryStream();
QRCode_BMP.Save(streamQR, System.Drawing.Imaging.ImageFormat.Jpeg); //save bitmap into memory stream in jpeg format System.Drawing.Image QR_Jpeg = System.Drawing.Image.FromStream(streamQR);// save memory stream to image file
XImage xImage = XImage.FromGdiPlusImage(QR_Jpeg);
gfx = XGraphics.FromPdfPage(page);
DrawImage(gfx, xImage, 0, 0, 100, 100); //This is not working
QRCode_BMP.Dispose();
streamQR.Close();
gfx.Dispose();

You create a QR code in QRCode_BMP and then you create an XImage from QR_Jpeg and write it is not working.
QRCode_BMP is only used to create a stream that is never used. We don't see where QR_Jpeg is coming from.
Provide a complete sample.
BTW: You can use XImage.FromStream to use the stream you created.
P.S.: IMHO JPEG is a bad choice for QR codes. Just use BMP and PDFsharp will use a lossless compression.

This is how I made it work;
PdfDocument pdf = PdfGenerator.GeneratePdf("<b>some html here</b>", PageSize.A4);
QRCodeGenerator qrGenerator = new QRCodeGenerator();
QRCodeData qrCodeData = qrGenerator.CreateQrCode("some text here", QRCodeGenerator.ECCLevel.Q);
QRCode qrCode = new QRCode(qrCodeData);
Bitmap qrCodeImage = qrCode.GetGraphic(10);
PdfPage page = pdf.Pages[0]; //I will add it to 1st page
// Get an XGraphics object for drawing
XGraphics gfx = XGraphics.FromPdfPage(page);
XImage image = XImage.FromGdiPlusImage(qrCodeImage); //you can use XImage.FromGdiPlusImage to get the bitmap object as image (not a stream)
gfx.DrawImage(image, 50, 50, 150, 150);
//save your pdf, dispose other objects

Using XImage.FromStream like #I liked the old Stack Overflow mentioned, in your posted code you should be able to just use:
var QRCode_BMP = _generalCode.QR_CodeGenerator(AddReviewPath); //This generates the bitmap
MemoryStream streamQR = new MemoryStream();
QRCode_BMP.Save(streamQR, System.Drawing.Imaging.ImageFormat.Jpeg); //save bitmap into memory stream in jpeg format System.Drawing.Image QR_Jpeg = System.Drawing.Image.FromStream(streamQR);// save memory stream to image file
//XImage xImage = XImage.FromGdiPlusImage(QR_Jpeg); // <-- Removed
gfx = XGraphics.FromPdfPage(page);
gfx.DrawImage(XImage.FromStream(streamQR), 0, 0, 100, 100); // <-- Added
//DrawImage(gfx, xImage, 0, 0, 100, 100); //This is not working // <-- Removed
QRCode_BMP.Dispose();
streamQR.Close();
gfx.Dispose();
For general usage of streams for XGraphics.DrawImage (library PDFSharp) here's some code I use to print SVG vector path data to PDF:
System.Windows.Shapes.Path path = new System.Windows.Shapes.Path();
// YouTube like button SVG vector path data:
path.Data = Geometry.Parse("M12.42,14A1.54,1.54,0,0,0,14,12.87l1-4.24C15.12,7.76,15,7,14,7H10l1.48-3.54A1.17,1.17,0,0,0,10.24,2a1.49,1.49,0,0,0-1.08.46L5,7H1v7ZM9.89,3.14A.48.48,0,0,1,10.24,3a.29.29,0,0,1,.23.09S9,6.61,9,6.61L8.46,8H14c0,.08-1,4.65-1,4.65a.58.58,0,0,1-.58.35H6V7.39ZM2,8H5v5H2Z");
// Visual check of the path:
// https://yqnn.github.io/svg-path-editor/
// Color area bordered through path of SVG vector:
path.Fill = new SolidColorBrush(Colors.Black);
// Upscale path, if final image is blurry:
double scale = 2;
path.RenderTransform = new ScaleTransform(scale, scale);
Rect bounds = path.Data.GetRenderBounds(null);
// Increase render bounds (here: "+ 4"), if parts of the path in the final image are cut off (test it with "scale = 1" before upscaling):
bounds.Width = (bounds.Width + 4) * scale;
bounds.Height = (bounds.Height + 4) * scale;
path.Measure(bounds.Size);
path.Arrange(bounds);
RenderTargetBitmap bitmap = new RenderTargetBitmap(
(int)bounds.Width, (int)bounds.Height, 96, 96, PixelFormats.Pbgra32);
bitmap.Render(path);
// Transparent areas are replaced with black pixels when using a "BmpBitmapEncoder", so instead use a "PngBitmapEncoder":
PngBitmapEncoder encoderPng = new PngBitmapEncoder();
encoderPng.Frames.Add(BitmapFrame.Create(bitmap));
using (MemoryStream stream = new MemoryStream())
{
encoderPng.Save(stream);
// Draw image to PDF using "XGraphics.DrawImage":
gfx.DrawImage(XImage.FromStream(stream), 10, 100, 14.05, 12.05);
}

install font on asp.net web server

i am using this code in my asp.net website. its barcode generation code.. problem this code is depend on (IDAutomationHC39M) this font. so on localhost i have installed this font in my fonts folder and code is working successfully in local. but i do not know how to install this on server
string barCode = Request.QueryString["id"].ToString();
System.Web.UI.WebControls.Image imgBarCode = new System.Web.UI.WebControls.Image();
using (Bitmap bitMap = new Bitmap(barCode.Length * 40, 80))
{
using (Graphics graphics = Graphics.FromImage(bitMap))
{
Font oFont = new Font("IDAutomationHC39M", 16);
PointF point = new PointF(2f, 2f);
SolidBrush blackBrush = new SolidBrush(Color.Black);
SolidBrush whiteBrush = new SolidBrush(Color.White);
graphics.FillRectangle(whiteBrush, 0, 0, bitMap.Width, bitMap.Height);
graphics.DrawString("*" + barCode + "*", oFont, blackBrush, point);
}
using (MemoryStream ms = new MemoryStream())
{
bitMap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
byte[] byteImage = ms.ToArray();
Convert.ToBase64String(byteImage);
imgBarCode.ImageUrl = "data:image/png;base64," + Convert.ToBase64String(byteImage);
}
plBarCode.Controls.Add(imgBarCode);
}

Assuming a web based font will not work (ie you need to render your barcode server side and possibly embed it with other graphics / images), you can take the following approach. I didn't write this code but have used it and it does work.
You will need to load your font from a resource or possibly via a URL. Then pass the bits to the following. If loading from a resource, google that as there are a fair number of examples.
You can also use fontCollection.AddFontFile() and simplify your code but that will require access to the local (on server) filesystem.
public FontFamily GetFontFamily(byte[] bytes)
{
FontFamily fontFamily = null;
var handle = GCHandle.Alloc(bytes, GCHandleType.Pinned);
try
{
var ptr = Marshal.UnsafeAddrOfPinnedArrayElement(bytes, 0);
var fontCollection = new PrivateFontCollection();
fontCollection.AddMemoryFont(ptr, bytes.Length);
fontFamily = fontCollection.Families[0];
}
finally
{
// don't forget to unpin the array!
handle.Free();
}
return fontFamily;
}

if you are developing for relatively modern browsers you can read up on #font-face
or, it may be just a simple matter of installing the font on your web server, typically you just need to copy the font file over to some folder on the server, say the desktop, and it should just be a simple matter of right clicking and selecting "install font"

How to preserve png transparency?

I created a function to allow uploaded transparent .png files to be inserted into a SQL Server database and the displayed on a web page via an HttpHandler.
While this all works, the png transparency changes to black when it's viewed on the web page. Is there a way of preserving the transparency?
Here's my image service which inserts into the database from the MVC controller:
public void AddImage(int productId, string caption, byte[] bytesOriginal)
{
string jpgpattern = ".jpg|.JPG";
string pngpattern = ".png|.PNG";
string pattern = jpgpattern;
ImageFormat imgFormat = ImageFormat.Jpeg;
if (caption.ToLower().EndsWith(".png"))
{
imgFormat = ImageFormat.Png;
pattern = pngpattern;
}
ProductImage productImage = new ProductImage();
productImage.ProductId = productId;
productImage.BytesOriginal = bytesOriginal;
productImage.BytesFull = Helpers.ResizeImageFile(bytesOriginal, 600, imgFormat);
productImage.BytesPoster = Helpers.ResizeImageFile(bytesOriginal, 198, imgFormat);
productImage.BytesThumb = Helpers.ResizeImageFile(bytesOriginal, 100, imgFormat);
productImage.Caption = Common.RegexReplace(caption, pattern, "");
productImageDao.Insert(productImage);
}
And here's the "ResizeImageFile" helper function:
public static byte[] ResizeImageFile(byte[] imageFile, int targetSize, ImageFormat imageFormat)
{
using (System.Drawing.Image oldImage = System.Drawing.Image.FromStream(new MemoryStream(imageFile)))
{
Size newSize = CalculateDimensions(oldImage.Size, targetSize);
using (Bitmap newImage = new Bitmap(newSize.Width, newSize.Height, PixelFormat.Format24bppRgb))
{
using (Graphics canvas = Graphics.FromImage(newImage))
{
canvas.SmoothingMode = SmoothingMode.AntiAlias;
canvas.InterpolationMode = InterpolationMode.HighQualityBicubic;
canvas.PixelOffsetMode = PixelOffsetMode.HighQuality;
canvas.DrawImage(oldImage, new Rectangle(new Point(0, 0), newSize));
MemoryStream m = new MemoryStream();
newImage.Save(m, imageFormat);
return m.GetBuffer();
}
}
}
}
What do I need to do to preserve the png transparency? Please show examples. I'm seriously not an expert with image manipulation.
Thanks.

Maybe try changing pixel format form PixelFormat.Format24bppRgb to PixelFormat.Format32bppRgb. You need the extra 8 bits to hold the alpha channel.

Using PixelFormat.Format32bppRgb didn't work for me. What worked however is using oldImage.PixelFormat when drawing the new image. So the corresponding line of code becomes:
using (Bitmap newImage = new Bitmap(newSize.Width, newSize.Height, oldImage.PixelFormat))

Can you open a JPEG, add text, and resave as a JPEG in .NET?

I want to write a small program in .NET 4.0 that will open a .jpg (or .jpeg) file, add a line of text to the image, and then resave the image as a .jpg. Does anyone know the easiest way to do this?
Thanks for any help.

Something like this:
var filePath = #"D:\Pictures\Backgrounds\abc.jpg";
Bitmap bitmap = null;
// Create from a stream so we don't keep a lock on the file.
using (var stream = File.OpenRead(filePath))
{
bitmap = (Bitmap)Bitmap.FromStream(stream);
}
using (bitmap)
using (var graphics = Graphics.FromImage(bitmap))
using (var font = new Font("Arial", 20, FontStyle.Regular))
{
// Do what you want using the Graphics object here.
graphics.DrawString("Hello World!", font, Brushes.Red, 0, 0);
// Important part!
bitmap.Save(filePath);
}

var myBitmap = new Bitmap("C:\\myImage.jpg");
var g = Graphics.FromImage(myBitmap);
g.DrawString("My\nText", new Font("Tahoma", 40), Brushes.White, new PointF(0, 0));