Using Direct2D from a service in C#
It is often desirable to create graphical images on disk from a service context. For example, some server applications need to render images and send back the generated bitmaps to users connected through web clients. One example would be an ASP.NET web application which needs to generate user profile pictures on the fly. We have observed that many developers choose to use GDI+ and System.Drawing to generate those images. However, GDI+ and System.Drawing are not supported in a service context or in a web application. Attempting to use System.Drawing within one of these application types may produce unexpected problems, such as diminished service performance and run-time exceptions (see the “Caution” section in msdn.microsoft.com/en-us/library/system.drawing.aspx). In addition, the WPF (Windows Presentation Foundation) graphics classes are unsupported in a service context. The use of WPF within a Windows service was a scenario that was not designed nor tested for. This is documented on MSDN here: msdn.microsoft.com/en-us/library/bb613549(v=vs.90).aspx .
Direct2D is the supported technology for rendering images to an image file on disk in a service context. Below is C# ASP.NET code which shows how to render a Direct2D scene to an image file on disk. This code can be used in any C# service. It demonstrates how to create a Direct2D bitmap based on image data in memory, draw Direct2D objects, such as an Ellipse and a Rectangle, and it also uses DirectWrite to render text. The code relies on the DirectX assembly from the Windows API Code Pack for Microsoft .NET Framework. This assembly provides developers access to Direct2D and DirectWrite from managed code. You will need to use the following file from the Windows API Code Pack for Microsoft .NET Framework, and add it as a reference to your project: Microsoft.WindowsAPICodePack.DirectX.dll See: archive.msdn.microsoft.com/WindowsAPICodePack The Windows API Code Pack for Microsoft .NET Framework is a free, managed source code library provided by Microsoft as is.
After you implement the C# code (below), then you should see an image on disk created as follows:
/**************************** Module Header ******************************\
' Copyright (c) Microsoft Corporation.
'
' This code demonstrates how to use Direct2D to render 2D objects and text to
' an image file on disk.
'
' THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
' EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
' WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
'**************************************************************************/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Microsoft.WindowsAPICodePack.DirectX;
using Microsoft.WindowsAPICodePack.DirectX.Direct2D1;
using Microsoft.WindowsAPICodePack.DirectX.WindowsImagingComponent;
using Microsoft.WindowsAPICodePack.DirectX.DirectWrite;
namespace D2DServerSide
{
public partial class _Default : System.Web.UI.Page
{
D2DFactory d2dFactory;
ImagingFactory wicFactory;
DWriteFactory dwriteFactory;
D2DBitmap d2dBitmapBarcode;
RenderTarget wicRenderTarget;
RenderTargetProperties renderProps = new RenderTargetProperties
{
PixelFormat = new PixelFormat(
Microsoft.WindowsAPICodePack.DirectX.Graphics.Format.B8G8R8A8UNorm,
AlphaMode.Ignore),
Usage = RenderTargetUsages.None,
RenderTargetType = RenderTargetType.Software
};
// Demonstrates how to create a Direct2D bitmap based on image data in memory
private void CreateBitmap()
{
// We have a 32 bpp Bitmap. This is one example.
// The width and height are: 69 x 23
var size = new SizeU((uint)69, (uint)23);
BitmapProperties bmpProp = new BitmapProperties(new PixelFormat(
Microsoft.WindowsAPICodePack.DirectX.Graphics.Format.B8G8R8A8UNorm,
AlphaMode.Ignore), wicRenderTarget.Dpi.X, wicRenderTarget.Dpi.Y);
d2dBitmapBarcode = wicRenderTarget.CreateBitmap(size, bmpProp);
int nWidth = (int)size.Width;
int nHeight = (int)size.Height;
byte[] testData = new byte[nWidth * nHeight * 4];
byte TestByte = 1;
int nCurrentDest = 0;
for (int y = 0; y < nHeight; y++)
{
for (int x = 0; x < nWidth; x++)
{
byte CurrByte = (byte)TestByte++;
testData.SetValue(CurrByte, nCurrentDest); // blue
testData.SetValue(CurrByte, nCurrentDest + 1); // green
testData.SetValue(CurrByte, nCurrentDest + 2); // red
nCurrentDest += 4;
}
}
d2dBitmapBarcode.CopyFromMemory(testData, ((uint)nWidth) * 4 );
}
protected void Button1_Click(object sender, EventArgs e)
{
//Create Factories.
d2dFactory = D2DFactory.CreateFactory(D2DFactoryType.Multithreaded);
wicFactory = ImagingFactory.Create();
dwriteFactory = DWriteFactory.CreateFactory();
float ShippingLabelWidth = 500.0f;
float ShippingLabelHeight = 500.0f;
SizeU size = new SizeU((uint)ShippingLabelWidth, (uint)ShippingLabelHeight);
ImagingBitmap wicBitmap = wicFactory.CreateImagingBitmap(
size.Width,
size.Height,
PixelFormats.Bgr32Bpp,
BitmapCreateCacheOption.CacheOnLoad);
wicRenderTarget =
d2dFactory.CreateWicBitmapRenderTarget(wicBitmap, renderProps);
// Create a sample Bitmap
CreateBitmap();
wicRenderTarget.BeginDraw();
wicRenderTarget.Clear(new ColorF(0, 1, 0, 1)); // clear the background
SolidColorBrush blackSolidColorBrush;
blackSolidColorBrush = wicRenderTarget.CreateSolidColorBrush(new ColorF(0, 0, 0, 1));
// Render an Ellipse
Ellipse ellipse = new Ellipse();
ellipse.Point = new Point2F(300.0f, 300.0f);
ellipse.RadiusX = 100.0f;
ellipse.RadiusY = 150.0f;
wicRenderTarget.DrawEllipse(ellipse, blackSolidColorBrush, 10.0f);
// Render a Rectangle
RectF rect;
rect = new RectF(130, 30, 200, 100);
wicRenderTarget.DrawRectangle(rect, blackSolidColorBrush, 10.0f);
// Render text rotated
TextFormat textFormat_Value;
textFormat_Value = dwriteFactory.CreateTextFormat("Arial", 17,
Microsoft.WindowsAPICodePack.DirectX.DirectWrite.FontWeight.Bold,
Microsoft.WindowsAPICodePack.DirectX.DirectWrite.FontStyle.Normal,
Microsoft.WindowsAPICodePack.DirectX.DirectWrite.FontStretch.Normal);
RectF renderText_Value;
renderText_Value = new RectF(10, 150, 180, 250);
wicRenderTarget.Transform = Matrix3x2F.Rotation(90, new Point2F(100, 95));
wicRenderTarget.DrawText("This is a test", textFormat_Value,
renderText_Value, blackSolidColorBrush);
wicRenderTarget.Transform = Matrix3x2F.Translation(0, 0);
RectF DrawBitmap_Rect;
DrawBitmap_Rect = new RectF(10, 275, 180, 350);
wicRenderTarget.DrawBitmap(d2dBitmapBarcode, 1.0f,
BitmapInterpolationMode.NearestNeighbor, DrawBitmap_Rect);
wicRenderTarget.EndDraw();
try
{
// This code will need write permissions to the folder on the server that
// you wish to save the image file to.
// You will need to grant permission to the "Network Service" user
// account.
wicBitmap.SaveToFile(wicFactory, ContainerFormats.Png,
"c:\\SampleFiles\\Images\\test.png");
}
catch (Exception ex)
{
// Catch the exception that is unhandled in TryCast.
Type ExceptionType = ex.GetType();
// Check for System.UnauthorizedAccessException here. You will need to
// grant permission
// to the "Network Service" user account for the folder on the server
// that you wish to save the image file to.
// Restore the original unhandled exception.
throw;
}
finally
{
// Clean up
d2dFactory.Dispose();
wicFactory.Dispose();
dwriteFactory.Dispose();
}
}
}
}
Run-time requirements for Direct2D:
- Windows 7 or Windows Vista with Service Pack 2 (SP2) and Platform Update for Windows Vista and later.
- Windows Server 2008 R2 or Windows Server 2008 with Service Pack 2 (SP2) and Platform Update for Windows Server 2008 and later.
For Windows XP and Windows Server 2003, you will need to use Win32 GDI. For more information on GDI, see: msdn.microsoft.com/en-us/library/windows/desktop/dd145203(v=vs.85).aspx
For more information on Direct2D, see:
msdn.microsoft.com/en-us/library/windows/desktop/dd370990(v=vs.85).aspx
For more information on the Windows API Code Pack for Microsoft .NET Framework, see:
archive.msdn.microsoft.com/WindowsAPICodePack
Comments
Anonymous
April 17, 2013
The comment has been removedAnonymous
April 17, 2013
The more easy language u will select, better will be the performance of your taskAnonymous
April 30, 2013
nice...