VintaSoft Twain .NET SDK v10.2
TWAIN devices

TWAIN device manager allows to show standard device selection dialog. Standard device selection dialog allows to view device list and select the default device. Standard device selection dialog can be shown using the DeviceManager.ShowDefaultDeviceSelectionDialog method.

Here is an example that shows how show standard TWAIN device selection dialog:

''' <summary>
''' Shows standard TWAIN device selection dialog.
''' </summary>
Private Sub ShowDeviceSelectionDialog()
    ' create device manager
    Using deviceManager As New DeviceManager()
        ' open device manager
        deviceManager.Open()

        ' show standard TWAIN device selection dialog
        deviceManager.ShowDefaultDeviceSelectionDialog()
    End Using
End Sub
              
/// <summary>
/// Shows standard TWAIN device selection dialog.
/// </summary>
void ShowDeviceSelectionDialog()
{
    // create device manager
    using (DeviceManager deviceManager = new DeviceManager())
    {
        // open device manager
        deviceManager.Open();

        // show standard TWAIN device selection dialog
        deviceManager.ShowDefaultDeviceSelectionDialog();
    }
}
                


Moreover TWAIN device manager allows to get device list programmatically. Device list can be get using the DeviceManager.Devices property. Information about the default device can be get using the DeviceManager.DefaultDevice property. Information about opened device can be get using the DeviceManager.OpenedDevice property.

Here is an example that shows how get information about all devices installed in the system:
''' <summary>
''' Gets information about all devices installed in the system.
''' </summary>
Private Sub GetDevicesInfo()
    ' create device manager
    Using deviceManager As New DeviceManager()
        ' open device manager
        deviceManager.Open()

        Dim devices As DeviceCollection = deviceManager.Devices
        ' for each device
        For i As Integer = 0 To devices.Count - 1
            ' output the device name
            Console.WriteLine(String.Format("Device '{0}'", devices(i).Info.ProductName))
        Next
    End Using
End Sub
              
/// <summary>
/// Gets information about all devices installed in the system.
/// </summary>
void GetDevicesInfo()
{
    // create device manager
    using (DeviceManager deviceManager = new DeviceManager())
    {
        // open device manager
        deviceManager.Open();

        DeviceCollection devices = deviceManager.Devices;
        // for each device
        for (int i = 0; i < devices.Count; i++)
        {
            // output the device name
            Console.WriteLine(string.Format("Device '{0}'", devices[i].Info.ProductName));
        }
    }
}
                



FAQ: I cannot see devices in the TWAIN selection dialog of my application but I can see them in other applications. Why?

Most probably you use your application in 64-bit system and your application is compiled as 64-bit application, in this case you need native 64-bit TWAIN driver for your device.

You can compile your application in "Any CPU" mode and in this case:

You can compile your application in "x86" mode and in this case:

You can compile your application in "x64" mode and in this case:

We recommend to use "x86" compilation mode because all scanners have 32-bit TWAIN drivers but only new and professional scanners have native 64-bit TWAIN drivers.