Acquiring an Image From WIA Source

Take the following steps to create and run a program that acquires an image from a WIA source.

1. Start Visual Studio .NET.

2. Choose File->New->Project… from the menu.

3. In the New Project dialog box, choose either "Visual C# Projects" or "VB Projects" in the Projects Type List, and choose "Windows Application" in the Templates List.

4. Type the project name as "Acquiring an Image From WIA Source" in the Project Name field, and then choose OK. If desired, type a new location for your project or select a directory using the Browse button, and then choose OK.

5. In the "Solution Explorer" window, right-click on the "References" folder, and select "Add Reference…" from the context menu. In the "Add Reference" dialog box, select the ".NET" tab and browse to the "<LEADTOOLS_INSTALLDIR>\Bin\DotNet4\Win32" folder and select the following DLLs:

   • Leadtools.dll
   • Leadtools.Wia.dll
   • Leadtools.Codecs.dll
   • Leadtools.Controls.WinForms.dll

   Click the Select button and then press the OK button to add the above DLLs to the application.

6. Make sure Form1 is in design view. Go to the toolbox (View->Toolbox) and Drag and drop an instance of ImageViewer to the form. If you do not have ImageViewer in your toolbox, select Tools->Choose Toolbox Items from the menu. Click Browse and then select Leadtools.Controls.WinForms.DLL from the "LEADTOOLS 19\Bin\DotNet4\Win32" folder and then click Open and then click OK.

7. Go to the toolbox (View->Toolbox) and Drag and drop a 2 instance of Button control to the top of the form and set the following properties for them:

1. Switch to Form1 code view (right-click Form1 in the solution explorer then select View Code) and add the following lines at the beginning of the file:

   C#

   VB
   Imports Leadtools 
   Imports Leadtools.Wia 
   Imports Leadtools.Codecs 
   Imports Leadtools.Controls.WinForms 
                    
        

   using Leadtools; 
   using Leadtools.Wia; 
   using Leadtools.Codecs; 
   using Leadtools.Controls.WinForms; 
                    
        

2. Declare the following private variable:

   C#

   VB
   Private WithEvents session As WiaSession 
                    
        

   private WiaSession session; 
                    
        

3. Add an event handler to the Form1 Load event and code it as follows:

   C#

   VB
   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
      Try 
         session = new WiaSession 
         session.Startup(WiaVersion.Version1) 
      Catch ex As Exception 
         MessageBox.Show(ex.Message) 
      End Try 
   End Sub 
                    
        

   private void Form1_Load(object sender, System.EventArgs e) 
   { 
      try 
      { 
         session = new WiaSession(); 
         session.Startup(WiaVersion.Version1); 
      } 
      catch (Exception ex) 
      { 
         MessageBox.Show(this, ex.Message); 
      } 
   } 
                    
        

4. Add an event handler to the Form1 Closing event and code it as follows:

   C#

   VB
   Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing 
      Try 
         session.Shutdown() 
      Catch ex As Exception 
         MessageBox.Show(ex.Message) 
      End Try 
   End Sub    
                    
        

   private void Form1_FormClosing(object sender, FormClosingEventArgs e) 
   { 
      try 
      { 
         session.Shutdown(); 
      } 
      catch (Exception ex) 
      { 
         MessageBox.Show(this, ex.Message); 
      } 
   } 
                    
        

5. Add the below code to handle the AcquireEvent event:

   C#

   VB
   Private Sub session_AcquireEvent(ByVal sender As Object, ByVal e As WiaAcquireEventArgs) Handles session.AcquireEvent 
     If Not e.Image Is Nothing Then 
        RasterImageViewer1.Image = e.Image 
     End If 
   End Sub 
                    
        

   private void session_AcquireEvent(object sender, WiaAcquireEventArgs e) 
   { 
     if (e.Image != null) 
     { 
        rasterImageViewer1.Image = e.Image; 
     } 
   } 
                    
        

6. Add an event handler to the btnAcquire Click event and code it as follows:

   C#

   VB
   Private Sub btnAcquire_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAcquire.Click 
      Try 
         session.Acquire(Me, Nothing, WiaAcquireFlags.ShowUserInterface Or WiaAcquireFlags.UseCommonUI) 
      Catch ex As Exception 
         MessageBox.Show(ex.Message) 
      End Try 
   End Sub    
                    
        

   private void btnAcquire_Click(object sender, System.EventArgs e) 
   { 
      try 
      { 
         session.AcquireEvent += new EventHandler<WiaAcquireEventArgs>(session_AcquireEvent); 
         session.Acquire(this, null, WiaAcquireFlags.ShowUserInterface |   WiaAcquireFlags.UseCommonUI); 
      } 
      catch (Exception ex) 
      { 
         MessageBox.Show(this, ex.Message); 
      } 
   } 
                    
        

7. Add an event handler to the btnSelectSource Click event and code it as follows:

   C#

   VB
   Private Sub btnSelectSource_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSelectSource.Click 
      Try 
         session.SelectDeviceDlg(Me, WiaDeviceType.Default, WiaSelectSourceFlags.NoDefault) 
      Catch ex As Exception 
         MessageBox.Show(ex.Message) 
      End Try 
   End Sub    
                    
        

   private void btnSelectSource_Click(object sender, System.EventArgs e) 
   { 
      try 
      { 
         session.SelectDeviceDlg(this, WiaDeviceType.Default, WiaSelectSourceFlags.NoDefault); 
      } 
      catch (Exception ex) 
      { 
         MessageBox.Show(this, ex.Message); 
      } 
   } 
                    
        

8. Build, and Run the program to test it.