Take the following steps to create and run a program that acquires an image from a TWAIN source.
- Start Visual Studio .NET.
- Choose File->New->Project… from the menu.
- 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.
- Type the project name as "Acquiring an Image" 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 .
- 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.
- Make sure Form1 is in design view. Go to the toolbox (View->Toolbox) and Drag and drop an instance of RasterImageViewer to the form. If you do not have RasterImageViewer in your toolbox, select Tools->Choose Toolbox Items from the menu. Click Browse and then select Leadtools.WinForms.DLL from "<LEADTOOLS_INSTALLDIR>\Bin\DotNet\Win32" and then click Open and then click OK.
- Go to the toolbox (View->Toolbox) and Drag and drop a 3 instance of RadioButton control to the top of the form and set the following properties for them:
| Text |
Name |
Checked |
| Native |
radioNative |
False |
| Memory |
radioMemory |
False |
| File |
radioFile |
False |
- Go to the toolbox (View->Toolbox) and Drag and drop a 4 instance of Button control to the top of the form and set the following properties for them:
| Text |
Name |
| Acquire |
buttonAcquire |
| Select Source |
buttonSelectSource |
| Save Template File |
buttonSaveTemplateFile |
| Load Template File |
buttonLoadTemplateFile |
- 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
[C#]
using Leadtools;
using Leadtools.Twain;
using Leadtools.Codecs;
using Leadtools.WinForms;
- Declare the following private variable:
[Visual Basic]
Private WithEvents twnSession As TwainSession
[C#]
private TwainSession twnSession;
- 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
twnSession = new TwainSession
twnSession.Startup(Me, "manufacturer", "productFamily", "version", "application", 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
{
twnSession = new TwainSession();
twnSession.Startup(this, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None);
}
catch (Exception ex)
{
MessageBox.Show(this, ex.Message);
}
}
- Add an event handler to the Form1 Closing event and code it as follows:
[Visual Basic]
Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.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);
}
}
- Add an event handler to the twnSession AcquirePage event and code it as follows:
[Visual Basic]
Private Sub twnSession_AcquirePage(ByVal sender As Object, ByVal e As TwainAcquirePageEventArgs) Handles twnSession.AcquirePage
RasterImageViewer1.Image = e.Image
End Sub
[C#]
private void twnSession_AcquirePage(object sender, TwainAcquirePageEventArgs e)
{
rasterImageViewer1.Image = e.Image;
}
- 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
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
{
twnSession.AcquirePage += new EventHandler<TwainAcquirePageEventArgs>(twnSession_AcquirePage);
twnSession.Acquire(TwainUserInterfaceFlags.Show);
}
catch (Exception ex)
{
MessageBox.Show(this, ex.Message);
}
}
- 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);
}
}
- Add an event handler to the buttonSaveTemplateFile Click event and code it as follows:
[Visual Basic]
Private Sub buttonSaveTemplateFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonSaveTemplateFile.Click
Try
twnSession.SaveTemplateFile("c:\test.ltt")
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
[C#]
private void buttonSaveTemplateFile_Click(object sender, System.EventArgs e)
{
try
{
twnSession.SaveTemplateFile(@"c:\test.ltt");
}
catch (Exception ex)
{
MessageBox.Show(this, ex.Message);
}
}
- Add an event handler to the buttonLoadTemplateFile Click event and code it as follows:
[Visual Basic]
Private Sub buttonLoadTemplateFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles buttonLoadTemplateFile.Click
Try
twnSession.LoadTemplateFile("c:\test.ltt")
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
[C#]
private void buttonLoadTemplateFile_Click(object sender, System.EventArgs e)
{
try
{
twnSession.LoadTemplateFile(@"c:\test.ltt");
}
catch (Exception ex)
{
MessageBox.Show(this, ex.Message);
}
}
- Add an event handler to the radioNative CheckedChanged event and code it as follows:
[Visual Basic]
Private Sub radioNative_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles radioNative.CheckedChanged
Try
Dim capability As New TwainCapability
capability.Information.ContainerType = TwainContainerType.OneValue
capability.Information.Type = TwainCapabilityType.ImageTransferMechanism
capability.OneValueCapability.ItemType = TwainItemType.Uint16
capability.OneValueCapability.Value = CUShort(TwainTransferMechanism.Native)
twnSession.SetCapability(capability, TwainSetCapabilityMode.Set)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
[C#]
private void radioNative_CheckedChanged(object sender, System.EventArgs e)
{
try
{
TwainCapability capability = new TwainCapability();
capability.Information.ContainerType = TwainContainerType.OneValue;
capability.Information.Type = TwainCapabilityType.ImageTransferMechanism;
capability.OneValueCapability.ItemType = TwainItemType.Uint16;
capability.OneValueCapability.Value = (UInt16)TwainTransferMechanism.Native;
twnSession.SetCapability(capability, TwainSetCapabilityMode.Set);
}
catch (Exception ex)
{
MessageBox.Show(this, ex.Message);
}
}
- Add an event handler to the radioMemory CheckedChanged event and code it as follows:
[Visual Basic]
Private Sub radioMemory_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles radioMemory.CheckedChanged
Try
Dim capability As New TwainCapability
capability.Information.ContainerType = TwainContainerType.OneValue
capability.Information.Type = TwainCapabilityType.ImageTransferMechanism
capability.OneValueCapability.ItemType = TwainItemType.Uint16
capability.OneValueCapability.Value = CUShort(TwainTransferMechanism.Memory)
twnSession.SetCapability(capability, TwainSetCapabilityMode.Set)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
[C#]
private void radioMemory_CheckedChanged(object sender, System.EventArgs e)
{
try
{
TwainCapability capability = new TwainCapability();
capability.Information.ContainerType = TwainContainerType.OneValue;
capability.Information.Type = TwainCapabilityType.ImageTransferMechanism;
capability.OneValueCapability.ItemType = TwainItemType.Uint16;
capability.OneValueCapability.Value = (UInt16)TwainTransferMechanism.Memory;
twnSession.SetCapability(capability, TwainSetCapabilityMode.Set);
}
catch (Exception ex)
{
MessageBox.Show(this, ex.Message);
}
}
- Add an event handler to the radioFile CheckedChanged event and code it as follows:
[Visual Basic]
Private Sub radioFile_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles radioFile.CheckedChanged
Try
Dim capability As New TwainCapability
capability.Information.ContainerType = TwainContainerType.OneValue
capability.Information.Type = TwainCapabilityType.ImageTransferMechanism
capability.OneValueCapability.ItemType = TwainItemType.Uint16
capability.OneValueCapability.Value = CUShort(TwainTransferMechanism.File)
twnSession.SetCapability(capability, TwainSetCapabilityMode.Set)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
[C#]
private void radioFile_CheckedChanged(object sender, System.EventArgs e)
{
try
{
TwainCapability capability = new TwainCapability();
capability.Information.ContainerType = TwainContainerType.OneValue;
capability.Information.Type = TwainCapabilityType.ImageTransferMechanism;
capability.OneValueCapability.ItemType = TwainItemType.Uint16;
capability.OneValueCapability.Value = (UInt16)TwainTransferMechanism.File;
twnSession.SetCapability(capability, TwainSetCapabilityMode.Set);
}
catch (Exception ex)
{
MessageBox.Show(this, ex.Message);
}
}
- Build, and Run the program to test it.
