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Patch WPF Tutorial

Patch Tutorial demonstrates incorporation of DGKCwpfn6 DG Kernel Control into a simple WPF .NET 8.0 application using Microsoft Visual Studio. Source code for Patch sample is available in Samples\NET\WPF\Patch\ folder of the installation directory.

See also: Sample List

This tutorial assumes basic familiarity with Visual Studio. It is based on Visual Studio 2022.

The Application

Patch application creates a new truncated cone and allows modification of its parameters.

Step 1. Creating the project

• Open Visual Studio. Select File > New > Project in the menu. In the "Create a new project" make sure C#, Windows and Desktop are current at the top. Select "WPF Application" project type. Click Next. Enter "Patch" for the project name. Select location and make sure .NET 8.0 is selected. Click Create.

• Close any open files. In Solution Explorer right-click the MainWindow.xaml created by default and rename it (using context menu on right-mouse click) to PatchForm.xaml.

Step 2. Inserting the DG Kernel WPF control

• In the Project menu of Visual Studio select "Manage NuGet Packages".

• Make sure you have 'DGK Installation' in the Package source combo list at the right top corner. Click the Settings button and add one pointing to the local installation folder like C:\Projects\DGKernel_7_4\Bin\AnyCPU

• Make sure 'DGK Installation' is the current source in the package source combo. You can also use nuget.org

• Open Browse tab of the NuGet Package Manager and select DGKCwpfn8. If you are using nuget.org source, type DGKCwpfn8 in the search box. This should display a single item.

• Select the item and click Install in the right-hand panel.

• Click Apply in the displayed dialogue. Close the NuGet manager.

• Double-click PatchForm.xaml in the Solution Explorer to open the form in Designer.

• In the XAML view (the code window) in the Window element change the Title to "Patch - Hello World (WPF)"

• Change size in the element to: Height="890" Width="532".

• Add DGKC assembly reference to the Window element by adding
  
  xmlns:wpfcontr="clr-namespace:DGKC;assembly=DGKCwpfn8"
  
  line below the last xmlns line.

• Add the DGKCwpfn8 control using the following code to the Grid element:

<wpfcontr:DGKCwpfn8 x:Name="m_dgkc"/>

• You can specify properties directly in the .xaml file or by using the Property Window.

• Right-click on the control and select Properties. The form shows properties of the control. The properties can also be accessed via the Properties Window of Visual Studio. The main one, ModelPath, can point to an .mdg model file or a file in any other supported format. We will leave it empty as our entity will be created in the code.

• Open the Object Browser (View > Object Browser menu option). Expand DGKCwpfn8 and its child node. This node displays all necessary information about types, interfaces and their methods available in the component.

Step 3. Creating the Entity 

• To create a handler for the Load event of the window, add property Loaded="Patch_Load" inside the Window tag. Right-click on event handler name and select "Go To Definition". A new Patch_Load() method will be added to the Patch class.

• Add line:

  using DGKC;

  at the top of the Patch.cs

• Next we will get access to the IModel_DG interface implemented by the control. Add to Patch_Load() the next line (without the (A) annotation):

  IModel_DG iModel = dgkc.GetModel();            (A)

• Add the following declarations to the Patch class:

  public IEntity_DG m_iEntity;
  public double m_baseRadius;
  public double m_topRadius;
  public double m_height;

• Initialise the parameters in Patch constructor as:

  m_baseRadius = 10;
  m_topRadius = 5;
  m_height = 10;

• Add the following three lines just below the line (A):

  IStdShape_DG iStdShape = iModel.As<IStdShape_DG>;
  m_iEntity = iStdShape.Cylinder(m_baseRadius, m_topRadius, m_height);
  iModel.AddEntity(m_iEntity);

  The first line obtains an interface for creation of basic shapes. The second line creates a cylindrical object and stores its reference in m_iEntity. The third line adds the entity to the model to be displayed in the 3D view.

• Add the following two lines at the end of Patch_Load():

  IView_DG iView = m_dgkc.GetView();
  iView.Reset(true, true);

  The first line accesses IView_DG, which is the root of the view-related functionality and the second line refits the view to include the new object.

Step 4. Implementing Modifications of the Object.

• Add three edit boxes for the parameters and an Apply button to the form. The controls can be copied in design mode from the installed completed version of the sample.

• Rename the edit boxes to: editBaseRad, editTopRad, editHeight.

• At the end of Patch constructor add the following to populate the edit boxes with default values:
  
editBaseRad.Text = m_baseRadius.ToString();
editTopRad.Text = m_topRadius.ToString();
editHeight.Text = m_height.ToString();

• In the handler of the Apply button, add: 

  m_baseRadius = Double.Parse(editBaseRad.Text);
  m_topRadius = Double.Parse(editTopRad.Text);
  m_height = Double.Parse(editHeight.Text);

  IModel_DG iModel = m_dgkc.GetModel();
  IStdShapeRef_DG iStdShapeRef = iModel.Query<IStdShapeRef_DG>();
  iStdShapeRef.Cylinder(m_baseRadius, m_topRadius, m_height, ref m_iEntity);

  m_dgkc.UpdateView();

  Notice the different version of interface used. IStdShapeRef_DG is designed for modification (and creation) rather than creation only. The last line redraws the window.

• Run the application and test modifications of the entity.