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Get Twain Capability

Take the following steps to start a project and to add some code to obtain a Twain Capability:

  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 "Visual Basic Projects" in the Projects Type List, and choose "Windows Application " in the Templates List.
  4. Type the project name as "GetTwainCapability" 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 click 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 Leadtools For .NET "\LEAD Technologies\LEADTOOLS 16.5\Bin\DotNet\Win32 " folder and select the following DLLs:
    • Leadtools.dll
    • Leadtools.Twain.dll
    • Leadtools.Codecs.dll
    • Leadtools.WinForms.dll
    Click the Select button and then click the OK button to add the above DLLs to the application.
  6. Go to the toolbox (View->Toolbox) and drag and drop 4 instances of the Button control to the top of the form and set the following properties for them:
    TextName
    Select SourcebuttonSelectSource
    Use CapabilitybuttonUseCapability
    Set BrightnessbuttonSetBrightness
    AcquirebuttonAcquire
  7. 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:

    [Visual Basic]

    						
    Imports Leadtools 
    Imports Leadtools.Twain 
    Imports Leadtools.Codecs 
    Imports Leadtools.WinForms
    
  8. Declare the following private variable:

    [Visual Basic]

    						
    Private WithEvents twnSession As TwainSession
    
    [C#]
    						
    private TwainSession twnSession;
    
  9. Add an event handler to the Form1 Load event and code it as follows:

    [Visual Basic]

    						
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
       Try 
          ' Unlock Document support. 
          ' Note that this is a sample key, which will not work in your toolkit. 
          RasterSupport.Unlock(RasterSupportType.Document, "TestKey") 
          twnSession = new TwainSession 
          twnSession.Startup(Me, "LEAD Technologies, Inc.", "LEAD Twain .NET", "Version 14", "LEADTools Twain test sample", TwainStartupFlags.None) 
       Catch ex As Exception 
          MessageBox.Show(ex.Message) 
       End Try 
    End Sub
    
    [C#]
    						
    private void Form1_Load(object sender, System.EventArgs e) 
    { 
       try 
       { 
          // Unlock Document support. 
          // Note that this is a sample key, which will not work in your toolkit. 
          RasterSupport.Unlock(RasterSupportType.Document, "TestKey"); 
          twnSession = new TwainSession(); 
          twnSession.Startup(this, "LEAD Technologies, Inc.", "LEAD Twain .NET", "Version 14", "LEADTools Twain test sample", TwainStartupFlags.None);
       } 
       catch (Exception ex) 
       { 
          MessageBox.Show(this, ex.Message); 
       } 
    }
    
  10. Add an event handler to the Form1 Closing event and code it as follows:

    [Visual Basic]

    						
    Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing 
       Try   
          twnSession.Shutdown() 
       Catch ex As Exception 
          MessageBox.Show(ex.Message) 
       End Try 
    End Sub
    
    [C#]
    						
    private void Form1_FormClosing(object sender, FormClosingEventArgs e) 
    { 
       try 
       { 
          twnSession.Shutdown();
       } 
          catch (Exception ex)
       {
          MessageBox.Show(this, ex.Message);
       } 
    }
    
  11. Add an event handler to the buttonSelectSource Click event and code it as follows:

    [Visual Basic]

    						
    Private Sub buttonSelectSource_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonSelectSource.Click 
       Try 
          twnSession.SelectSource(String.Empty) 
       Catch ex As Exception 
          MessageBox.Show(ex.Message) 
       End Try 
    End Sub
    
    [C#]
    						
    private void buttonSelectSource_Click(object sender, System.EventArgs e)
    { 
       try 
       { 
          twnSession.SelectSource(string.Empty);
       } 
       catch (Exception ex)
       { 
          MessageBox.Show(this, ex.Message);
       }
    }
    
  12. Add an event handler to the buttonUseCapability Click event and code it as follows:

    [Visual Basic]

    						
    Private Sub buttonUseCapability_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonUseCapability.Click 
       Try 
          Dim twGetCapability As TwainCapability = twnSession.GetCapability(TwainCapabilityType.ImageTransferMechanism, TwainGetCapabilityMode.GetCurrent) 
          If twGetCapability.Information.ContainerType = TwainContainerType.OneValue Then 
             Dim capValue As TwainCapabilityValue = twGetCapability.OneValueCapability.Value 
             If capValue <> TwainCapabilityValue.TransferMechanismFile Then 
                Dim twSetCapability As TwainCapability 
                twSetCapability = new TwainCapability 
                twSetCapability.Information.ContainerType = TwainContainerType.OneValue 
                twSetCapability.Information.Type = TwainCapabilityType.ImageTransferMechanism 
                twSetCapability.OneValueCapability.ItemType = TwainItemType.Uint16 
                twSetCapability.OneValueCapability.Value = TwainCapabilityValue.TransferMechanismFile 
                twnSession.SetCapability(twSetCapability, TwainSetCapabilityMode.Set) 
             End If 
          End If 
       Catch ex As Exception 
          MessageBox.Show(ex.Message) 
       End Try 
    End Sub
    
    [C#]
    						
    private void buttonUseCapability_Click(object sender, System.EventArgs e)
    { 
       try 
       { 
          TwainCapability twGetCapability = twnSession.GetCapability(TwainCapabilityType.ImageTransferMechanism, TwainGetCapabilityMode.GetCurrent); 
          
          if (twGetCapability.Information.ContainerType == TwainContainerType.OneValue) 
          { 
             TwainCapabilityValue capValue = (TwainCapabilityValue)twGetCapability.OneValueCapability.Value; 
             if (capValue != TwainCapabilityValue.TransferMechanismFile) 
             { 
                TwainCapability twSetCapability; 
                twSetCapability = new TwainCapability(); 
                twSetCapability.Information.ContainerType = TwainContainerType.OneValue; 
                twSetCapability.Information.Type = TwainCapabilityType.ImageTransferMechanism; 
                twSetCapability.OneValueCapability.ItemType = TwainItemType.Uint16; 
                twSetCapability.OneValueCapability.Value = TwainCapabilityValue.TransferMechanismFile; 
                twnSession.SetCapability(twSetCapability, TwainSetCapabilityMode.Set); 
             } 
          } 
       } 
       catch (Exception ex) 
       { 
          MessageBox.Show(this, ex.Message);
       } 
    }
    
  13. Add an event handler to the buttonSetBrightness Click event and code it as follows:

    [Visual Basic]

    						
    Private Sub buttonSetBrightness_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonSetBrightness.Click 
       Try 
          Dim twCapability As TwainCapability = new TwainCapability 
          twCapability.Information.ContainerType = TwainContainerType.OneValue 
          twCapability.Information.Type = TwainCapabilityType.ImageBrightness 
          Dim brightneesValue As Integer = 50 
          twCapability.OneValueCapability.ItemType = TwainItemType.Fix32 
          twCapability.OneValueCapability.Value = brightneesValue 
          twnSession.SetCapability(twCapability, TwainSetCapabilityMode.Set) 
       Catch ex As Exception 
          MessageBox.Show(ex.Message) 
       End Try 
    End Sub
    
    [C#]
    						
    private void buttonSetBrightness_Click(object sender, System.EventArgs e) 
    { 
       try 
       { 
          TwainCapability twCapability = new TwainCapability(); 
          twCapability.Information.ContainerType = TwainContainerType.OneValue; 
          twCapability.Information.Type = TwainCapabilityType.ImageBrightness; 
          float brightneesValue = 50; 
          twCapability.OneValueCapability.ItemType = TwainItemType.Fix32; 
          twCapability.OneValueCapability.Value = brightneesValue; 
          twnSession.SetCapability(twCapability, TwainSetCapabilityMode.Set); 
       } 
       catch (Exception ex) 
       { 
          MessageBox.Show(this, ex.Message); 
       } 
    }
    
  14. Add an event handler to the buttonAcquire Click event and code it as follows:

    [Visual Basic]

    						
    Private Sub buttonAcquire_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonAcquire.Click 
       Try 
          Dim twnPros As TwainProperties = twnSession.Properties 
          Dim dataTransfer As TwainDataTransferProperties = twnPros.DataTransfer 
          dataTransfer.FileName = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) & "//LEADTOOLS Images//" & "Twain.bmp" 
          twnPros.DataTransfer = dataTransfer 
          twnSession.Properties = twnPros 
          twnSession.Acquire(TwainUserInterfaceFlags.Show) 
       Catch ex As Exception 
          MessageBox.Show(ex.Message) 
       End Try 
    End Sub
    
    [C#]
    						
    private void buttonAcquire_Click(object sender, System.EventArgs e) 
    { 
       try 
       { 
          TwainProperties twnPros = twnSession.Properties; 
          TwainDataTransferProperties dataTransfer = twnPros.DataTransfer; 
          dataTransfer.FileName = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) + "//LEADTOOLS Images//" + "Twain.bmp"; 
          twnPros.DataTransfer = dataTransfer; 
          twnSession.Properties = twnPros; 
          twnSession.Acquire(TwainUserInterfaceFlags.Show); 
       } 
       catch (Exception ex) 
       { 
          MessageBox.Show(ex.Message); 
       } 
    }
    
  15. Build, and Run the program to test it.