Webform Charting Asp.Net Custom Control Walkthrough in VB / Visual Basic VS2013

[ VB Server-Side Development ]

This page includes VB instructions for VS2017 / VS2013 / VS2012. Click here of VS2010.

ProEssentials WebForm interfaces serve dynamically generated images and ActiveX binary states.

ProEssentials' strength is rendering quality and robustness: Where a chart shape, size, and large annotation property set can dynamcially produce a quality chart saturated with details.

Adding the ActiveX option to your IE visitors allows for uncompromising desktop functionality within a webpage.

You will implement server side behavior in pairs of files. One file, either .HTML or .ASPX will contain an image tag or ActiveX object tag with source attributes pointing to a secondary .ASPX page which will dynamically generate the respective binary content. Why two webform pages? The answer is that the first webform renders as viewable ascii html and the second webform renders as non-viewable binary data.

The ProEssentials WebForm interfaces have only a few key properties and one event which will control server-side specific functionality:

RenderingType This property controls how this instance of the control is rendered.
Possible settings are:
- ImageMap, render as an image tag followed by an ImageMap tag.
- ActiveX, render as an ActiveX object tag.
- BinaryImageStream, render as binary data representing image data.
- BinaryActiveXStream, render as binary data representing an ActiveX binary state upon page load.
- BinaryDataStream use with client side EXE or IE LoadFromUrl to update/append real-time data from the cloud/server to the client side chart.


When RenderingType is set to BinaryImageStream, this property controls the format of the binary image data. Possible settings are SVG, PNG, and JPEG. SVG producing an HTML5 chart.
ImageUrl When RenderingType is set to ImageMap, this property must point to a URL identifying an .ASPX page containing a ProEssentials control with its RenderingType property set to BinaryImageStream.
When RenderingType is set to ActiveX, this property must point to a URL identifying an .ASPX page containing a ProEssentials control with its RenderingType property set to BinaryActiveXStream.
CodebaseUrl When RenderingType is set to ActiveX, this property may optionally be used to point to a CAB file containing the ActiveXs and DLL to support automatic installation onto the client system.

Also, there is one Event and one EventArgs which is used to implement image map support.

PeImageMap This event is only used when the RenderingType property is set to ImageMap.
This event will be triggered (generally multiple occurrences) during the image generation process when hot spots have been enabled via properties found within the PeUserInterface.HotSpot namespace.


This object is passed to the PeImageMap event to communicate parameters with the developer.
Members include these properties:
- HotSpotType, defined as Gigasoft.ProEssentials.Enums.HotSpotType.
- Data1, its meaning is dependent upon HotSpotType.
- Data2, its meaning is dependent upon HotSpotType.
Members also include these write only properties:
- ToolTip, optionally set to assign tool tip text to image map area.
- Href, optionally set to assign a URL to image map area.
- Attributes, optionally set to assign attributes to map area such as VBScript.

It is recommended that the namespace: Gigasoft.ProEssentials.Enums be included at the top of your source code files utilizing ProEssentials. In Visual Basic, use the usings keyword. For example:

using Gigasoft.ProEssentials.Enums;


The following information demonstrates how to create your first ASP.NET / ProEssentials implementation using Visual Basic. It discusses using ASP.NET to serve up a dynamically generated PNG image. Also refer to the "ReadMe.htm", "AspNetReadMe.htm", and "AspReadMe.htm" files installed onto your system with the eval/product (accessible via Start menu).

1) Start Visual Studio.NET and create a new WebSite project targeting an ASP.NET Web Application using Visual Basic as our language. Accept the default name of [WebSite1].

Starting a VS2012 VisualBasic webform asp.net project.

2)When the new project opens, you will be presented the design view of "Default.aspx".

If you have already installed the ProEssentials WebForm interfaces, skip to step 4.

Customize Toolbox... Dialog Adding ProEssentials to Visual Basic.NET...

3)Installing Asp.Net controls into Visual Studio.NET

VS2017 / VS2013 / VS2010 Instructions

  • Under the Tools menu, select [Choose Toolbox Items...],
  • If not selected, left click the [.NET Framework Components] tab,
  • Left click the [Browse...] button and find the file "Gigasoft.ProEssentialsWeb.dll" found in the DotNetAnyCpu subdirectory where you installed ProEssentials. By default, this should be located at "C:\ProEssentials9\DotNetAnyCpu\",
  • Select the file "Gigasoft.ProEssentialsWeb.dll" and close the [Open File] dialog,
  • The [Choose Toolbox Items] dialog should now show 6 highlighted controls: Pe3doWeb, PegoWeb, PepcoWeb, PepsoWeb, PesgoWeb, and Pedo.
  • Close the dialog and the 6 new ProEssentials components will be at the bottom of the toolbox.
    vb.net charting component toolbar items within vs2012.
Default.aspx [Design]... Adding ProEssentials to a Form...
Charting Webform asp.net control within Visual Basic

4) Add a new paragraph to the Default. aspx page as shown. Click the PegoWeb tool icon in palette and drag the tool to your new paragraph. The adjacent image shows what you see using VS2013.

This represents the default state of a ProEssentials Graph. The default state has one subset with four data points. In the course of constructing your own graphs, you'll set the properties PeData.Subsets and PeData.Points which define the quantity of data your graph will hold. You'll then pass data via the PeData.Y(subset, point) two dimensional property array. The following section shows example code of passing data.

ProEssentials uses the terms Subsets and Points but you can think of these as Rows and Columns. Passing data is as simple as filling each Subset with Points worth of data.

Adjusting design time settings...
Charting Webform asp.net control property window

5) Double check that the RenderingType property within the Properties window shows the default state of ImageMap. If blank, ImageMap is the default, though adding the setting will clarify the project.

6) Within the Properties window, change the ImageUrl property to "Default2.aspx".

7) Within Visual Studio's main menu, select [WebSite] and then [Add New Item...] and add a new Webform. Accept the default name of "Default2.aspx".


Default2.aspx [Code]...

8) Double click the PegoWeb tool within the toolbox and this places an instance of the PegoWeb component within "Default2.aspx".

9) Within the Properties window, change the RenderingType property to BinaryImageStream.

Charting Webform asp.net control rendering of image as binary data to server to an image tag.

10) Within Visual Studio's main menu, select [View] and then [Markup].

11) Remove all HTML content from this page. The resulting Markup / HTML Source content should only be tags...

Charting Webform asp.net control ASPX Tag

NOTE: It is important the entire page looks as above. No ascii characters can be outside < > tags, not even a space character. Any ascii would corrupt the binary data being served to Default.aspx on the client. If there is mistakenly ascii, Default.aspx may show a red x instead of an image as the binary data received from server is not recognized as a bitmap.

12) Within Visual Studio's main menu, select [View] and then [Code].

13) Add the following code to the Page_Load event handler. Type it in manually to see examples of embedded XML help and other intellisense features.

PegoWeb1.PeString.MainTitle = "Hello World"
PegoWeb1.PeString.SubTitle = ""
PegoWeb1.PeData.Subsets = 2
PegoWeb1.PeData.Points = 6
PegoWeb1.PeData.Y(0, 0) = 10 : PegoWeb1.PeData.Y(0, 1) = 30
PegoWeb1.PeData.Y(0, 2) = 20 : PegoWeb1.PeData.Y(0, 3) = 40
PegoWeb1.PeData.Y(0, 4) = 30 : PegoWeb1.PeData.Y(0, 5) = 50
PegoWeb1.PeData.Y(1, 0) = 15 : PegoWeb1.PeData.Y(1, 1) = 63
PegoWeb1.PeData.Y(1, 2) = 75 : PegoWeb1.PeData.Y(1, 3) = 54
PegoWeb1.PeData.Y(1, 4) = 25 : PegoWeb1.PeData.Y(1, 5) = 43
PegoWeb1.PeString.PointLabels(0) = "Jan"
PegoWeb1.PeString.PointLabels(1) = "Feb"
PegoWeb1.PeString.PointLabels(2) = "Mar"
PegoWeb1.PeString.PointLabels(3) = "Apr"
PegoWeb1.PeString.PointLabels(4) = "May"
PegoWeb1.PeString.PointLabels(5) = "June"
PegoWeb1.PeString.SubsetLabels(0) = "For .Net Framework"
PegoWeb1.PeString.SubsetLabels(1) = "or MFC, ActiveX, VCL"
PegoWeb1.PeString.YAxisLabel = "Simple Quality Rendering"
PegoWeb1.PeColor.SubsetColors(0) = System.Drawing.Color.FromArgb(120, 0, 180, 0)
PegoWeb1.PeColor.SubsetColors(1) = System.Drawing.Color.FromArgb(80, 0, 0, 130)
PegoWeb1.PeColor.BitmapGradientMode = True
PegoWeb1.PeColor.QuickStyle = Gigasoft.ProEssentials.Enums.QuickStyle.LightShadow
PegoWeb1.PeColor.Desk = System.Drawing.Color.FromArgb(255, 122, 192, 218)
PegoWeb1.PeTable.Show = Gigasoft.ProEssentials.Enums.GraphPlusTable.Both
PegoWeb1.PeData.Precision = Gigasoft.ProEssentials.Enums.DataPrecision.NoDecimals
PegoWeb1.PeFont.Label.Bold = True
PegoWeb1.PePlot.Method = Gigasoft.ProEssentials.Enums.GraphPlottingMethod.Bar
PegoWeb1.PePlot.Option.GradientBars = 8
PegoWeb1.PePlot.DataShadows = Gigasoft.ProEssentials.Enums.DataShadows.ThreeDimensional
PegoWeb1.PeFont.FontSize = Gigasoft.ProEssentials.Enums.FontSize.Large
PegoWeb1.PeUserInterface.HotSpot.Data = True
PegoWeb1.PeLegend.Location = Gigasoft.ProEssentials.Enums.LegendLocation.Left
PegoWeb1.PePlot.Option.BarGlassEffect = True
PegoWeb1.PeConfigure.RenderEngine = Gigasoft.ProEssentials.Enums.RenderEngine.GdiPlus
PegoWeb1.PeConfigure.AntiAliasGraphics = True
PegoWeb1.PeConfigure.AntiAliasText = True

Once entered, select this code and copy it to clipboard.

14) Within Visual Studio's main menu, select [Window] and then "Default.aspx"

15) Within Visual Studio's main menu, select [View] and then [Code]

16) Paste the above code into the Page_Load event handler for "Default.aspx". Thus both "Default.aspx.vb" and "Default2.aspx.vb" now contain similar Page_Load code.

17) Add one additional line of code to the "Default.aspx.vb"

PegoWeb1.PeUserInterface.HotSpot.Data = True

The Page_Load handler within "Default.aspx.vb" should look similar as below...

Charting Webform asp.net control example vb source code

18) Within Visual Studio's main menu, select [Window] and then [Default.aspx]. Left click the PegoWeb control within the form to give it the focus. Then left click the [Event] icon within the [Properties] window. Double click the PeImageMap event which opens the file "Default.aspx.vb" located at the PegoWeb1_PeImageMap event handler.

Webform Charting asp.net control imagemap event

19) Add the following code to the _PeImageMap handler...

If (e.HotSpotType = Gigasoft.ProEssentials.Enums.HotSpotType.DataPoint) Then
e.ToolTip = "Point " + e.Data2.ToString() + " with a value of " + PegoWeb1.PeData.Y(e.Data1, e.Data2).ToString()
End If

20) Run the project. Your browser will show an image as follows. Move the mouse over bars to see the image map content.

Run the project... Serving up a PNG...

Charting webform app.net control within the browser

You'll notice that nearly identical code was required for "Default.aspx. vb" and "Default2.aspx.vb" except for the hot spot code which triggers the PeImageMap event. Anytime you develop with image maps, you will need to have similar initialization code for both forms. Also, the control size on both forms must be set to the same size.

This completes this walkthrough. If you do not wish to support image maps, ignore the PeUserInterface.HotSpot and the PeImageMap event handler code. If not using image maps, you will only need code within "Default2.aspx.vb" and could actually replace Default.aspx's instance of a ProEssentials asp.net control with a generic html image tag.

For SVG Charting: set RenderedImageType for Default2.aspx from PNG to SVG.

For ActiveX: and working with Internet Explorer, change the RenderingType setting for "Default.aspx" to ActiveX, and the RenderingType setting on "Default2.aspx" to BinaryActiveXStream. The browser will contain a fully interactive charting control. Right click the control to access the user interface. Read the AspReadme for client-side examples and CAB file issues.


Online developer reference

Complete online technical reference to the ProEssentials product. Chapter 2's .NET Reference is the best mechanism to navigate the large quantity of properties and features.  Walk-Throughs of .NET charting in VB.NET, C#.NET, ASP, VC, and Delphi get you started quickly.

See Chapter 2 for more Asp.Net graphing Info

Online interactive demo

Financial, Engineering, Scientific, and Business examples give you an instant taste of ProEssentials' power.

view our online .Net Graph Demo

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