|Chapter 2: VB ASP.NET Charting Walk-Through VS2012 VS2013 VS2017
ProEssentials' web strength is in rendering quality and robustness: Where a chart shape, size, and large annotation property set can automatically produce a quality image packed with details. Our SVG HTML5 chart rendering option is also true vector output and great for HTML5 based reporting where printed output produces razor sharp results via very small file sizes.
ActiveX rendering is an option for those wanting to provide Internet Explorer users with desktop functionality within a webpage. If ActiveX is targeted, we recommend that you also review the standard ASP/ActiveX technical information in Chapter3 and AspReadme.
One 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 first webform renders as viewable ascii html and the second webform renders as non-viewable binary data. The first form usually contains a ProEssentials object with the RenderingType set to ImageMap or ActiveX. The second form then respectively has a ProEssentials object with the RenderingType set to BinaryImageStream or BinaryActiveXStream. The two forms work in unison to provide the complete ProEssentials implementation.
See a similar pre-built example within the included ProEssentials8/PE8WebDemo directory. See example 1-4, with related files within the Walk-Through1, Walk-Through2, Walk-Through3, and Walk-Through4 folders.
The ProEssentials WebForm interfaces have a few key properties and one event which will control server-side specific functionality. These are as follows:
This property controls
how this instance of the control is rendered.
Possible settings are:
- ImageMap, the control is rendered as an image tag followed by
an ImageMap tag.
- ActiveX, the control is rendered as an ActiveX object tag.
- BinaryImageStream, render as binary data representing image data.
- BinaryActiveXStream, render as binary data representing an ActiveX
- BinaryDataStream, used with client side EXE or IE call to LoadFromUrl method to update chart.
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.
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.
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.
there is one Event and one EventArgs which is used to implement image
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
It is recommended that the namespace: Gigasoft.ProEssentials.Enums be included at the
top of your source code files utilizing ProEssentials.
In VB.NET, use the Imports keyword. For example:
1) Start Visual Studio.NET and create a new
WebSite project targeting an ASP.NET Web Application using VB as our language.
Accept the default name of [WebSite1].
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.
ProEssentials to Visual Studio.NET...|
3) Installing WebForm interfaces into Visual Studio.NET
- 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:\ProEssentials8\DotNetAnyCpu",
Select the file "Gigasoft.ProEssentialsWeb.dll" and close the [Open File] dialog,
The [Choose Toolbox Items] dialog should now show highlighted controls: Pe3doWeb, PegoWeb, PepcoWeb, PepsoWeb, PesgoWeb, and Pedo data control.
Close the dialog and the 6 new ProEssentials components will be at the bottom of the toolbox.
ProEssentials to a Form...|
4) Add a new <p> paragraph as shown. Click the PegoWeb control within the tool palette and drag to your new paragraph. The adjacent image to left shows what your screen should resemble.
represents the default state of a ProEssentials Graph. The default state
has one subset with four data points. In the course of initializing your
own charts, you'll set the properties PeData.Subsets
and PeData.Points which define the quantity of data your chart
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.
design time settings...|
5) Check that the RenderingType property within the Properties window shows
the default setting ImageMap.
6) Within the Properties window, change the
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".
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
property to BinaryImageStream.
10) Within Visual Studio's main menu, select
and then [Markup].
Remove all HTML content from
this page. The resulting Markup or HTML Source content should only be tags...
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. The client is expecting pure binary data from Default2.aspx which represents an image. If there is mistakenly some 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
and then [Code].
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
entered, select this code and copy it to clipboard.
14) Within Visual Studio's main menu, select
and then "Default.aspx" the first Webform created with project.
15) Within Visual Studio's main menu, select
and then [Code]
16) Paste the above code into the Page_Load
event handler for "Default.aspx".
17) Add one additional line of code to the "Default.aspx.vb"
handler should look similar to...
18) Add the event to Default.aspx to dynamically prepare results for imagemap events via the event [PeImageMap].
Add the following code to the _PeImageMap
= Gigasoft.ProEssentials.Enums.HotSpotType.DataPoint) Then
e.ToolTip = "Point " + e.Data2.ToString() + "
with a value of " + PegoWeb1.PeData.Y(e.Data1, e.Data2).ToString()
Run the project and your browser
will show an image as follows. Move the mouse over bars to see the image
up a PNG...|
notice that nearly identical code was required for "Default.aspx.vb"
and "Default2.aspx.vb" except for the hot spot code which triggers
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
should be set to the same size.
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 Default could contain a simple html image tag instead of a chart object.
For SVG charting:
remove the HotSpot.Data setting from both pages and 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.