Get Twain Capability

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

  1. Start Visual Studio.

  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 "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 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 Leadtools For .NET "<LEADTOOLS_INSTALLDIR>\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 press 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 Button control to the top of the form and set the following properties for them:
Text Name
Select Source buttonSelectSource
Use Capability buttonUseCapability
Set Brightness buttonSetBrightness
Acquire buttonAcquire
  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:

    VB
    Imports Leadtools 
    Imports Leadtools.Twain 
    Imports Leadtools.Codecs 
    Imports Leadtools.WinForms 
                     
         

    C#
    using Leadtools; 
    using Leadtools.Twain; 
    using Leadtools.Codecs; 
    using Leadtools.WinForms; 
                     
         

  2. Declare the following private variable:

    VB
    Private WithEvents twnSession As TwainSession 
                     
         

    C#
    private TwainSession twnSession; 
                     
         

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

    VB
    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. 
          Dim MY_LICENSE_FILE As String = "d:\temp\TestLic.lic" 
          Dim MY_DEVELOPER_KEY As String = "xyz123abc" 
          RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY) 
          twnSession = new TwainSession 
          twnSession.Startup(Me.Handle, "LEAD Technologies, Inc.", "LEAD TWAIN .NET", "Version 16", "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. 
          string MY_LICENSE_FILE = "d:\\temp\\TestLic.lic"; 
          string MY_DEVELOPER_KEY = "xyz123abc"; 
          RasterSupport.SetLicense(MY_LICENSE_FILE, MY_DEVELOPER_KEY); 
          twnSession = new TwainSession(); 
          twnSession.Startup(this.Handle, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None); 
       } 
       catch (Exception ex) 
       { 
          MessageBox.Show(this, ex.Message); 
       } 
    } 
                     
         

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

    VB
    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); 
       } 
    } 
                     
         

  5. Add an event handler to the buttonSelectSource Click event and code it as follows:

    VB
                      
    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); 
       } 
    } 
                     
         

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

    VB
    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); 
       } 
    } 
                     
         

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

    VB
    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 brightnessValue As Integer = 50 
          twCapability.OneValueCapability.ItemType = TwainItemType.Fix32 
          twCapability.OneValueCapability.Value = brightnessValue 
                           
          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 brightnessValue = 50; 
          twCapability.OneValueCapability.ItemType = TwainItemType.Fix32; 
          twCapability.OneValueCapability.Value = brightnessValue; 
                           
          twnSession.SetCapability(twCapability, TwainSetCapabilityMode.Set); 
       } 
       catch (Exception ex) 
       { 
          MessageBox.Show(this, ex.Message); 
       } 
    } 
                     
         

  8. Add an event handler to the buttonAcquire Click event and code it as follows:

    VB
    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 = "C:\Users\Public\Documents\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 = @"C:\Users\Public\Documents\LEADTOOLS Images\Twain.bmp"; 
          twnPros.DataTransfer = dataTransfer; 
          twnSession.Properties = twnPros; 
          twnSession.Acquire(TwainUserInterfaceFlags.Show); 
       } 
       catch (Exception ex) 
       { 
          MessageBox.Show(ex.Message); 
       } 
    } 
                     
         

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