Cancel image acquisition from WIA image scanner
In This Topic
You should call the
WiaDevice.Close method if you want to cancel the image acquisition from the automatic document feeder (ADF) of WIA image scanner.
Here is an example that demonstrates how to cancel the current synchronous image transfer from WIA scanner:
/// <summary>
/// Acquires one image from WIA device and cancels image transfer.
/// </summary>
public static void AcquireOneImageFromWiaDeviceAndCancelScan()
{
// create WIA device manager
using (Vintasoft.WiaImageScanning.WiaDeviceManager deviceManager = new Vintasoft.WiaImageScanning.WiaDeviceManager())
{
// open WIA device manager
deviceManager.Open();
// get count of WIA devices
int deviceCount = deviceManager.Devices.Count;
if (deviceCount == 0)
{
System.Console.WriteLine("Devices are not found.");
return;
}
// select the first WIA device
Vintasoft.WiaImageScanning.WiaDevice device = deviceManager.Devices[0];
// open WIA device
device.Open();
Vintasoft.WiaImageScanning.WiaAcquiredImage acquiredImage;
do
{
try
{
// acquire image from WIA device
acquiredImage = device.AcquireImageSync();
// if image is received
if (acquiredImage != null)
{
System.Console.WriteLine("Image is acquired.");
// close the device
device.Close();
}
// if image is not received
else
{
System.Console.WriteLine("Scan is completed.");
break;
}
}
catch (System.Exception ex)
{
System.Console.WriteLine(string.Format("Scan is failed: {0}", ex.Message));
break;
}
}
// while image is acquired
while (acquiredImage != null);
// close WIA device
device.Close();
// close WIA device manager
deviceManager.Close();
}
System.Console.ReadLine();
}
''' <summary>
''' Acquires one image from WIA device and cancels image transfer.
''' </summary>
Public Shared Sub AcquireOneImageFromWiaDeviceAndCancelScan()
' create WIA device manager
Using deviceManager As New Vintasoft.WiaImageScanning.WiaDeviceManager()
' open WIA device manager
deviceManager.Open()
' get count of WIA devices
Dim deviceCount As Integer = deviceManager.Devices.Count
If deviceCount = 0 Then
System.Console.WriteLine("Devices are not found.")
Return
End If
' select the first WIA device
Dim device As Vintasoft.WiaImageScanning.WiaDevice = deviceManager.Devices(0)
' open WIA device
device.Open()
Dim acquiredImage As Vintasoft.WiaImageScanning.WiaAcquiredImage
Do
Try
' acquire image from WIA device
acquiredImage = device.AcquireImageSync()
' if image is received
If acquiredImage IsNot Nothing Then
System.Console.WriteLine("Image is acquired.")
' close the device
device.Close()
Else
' if image is not received
System.Console.WriteLine("Scan is completed.")
Exit Try
End If
Catch ex As System.Exception
System.Console.WriteLine(String.Format("Scan is failed: {0}", ex.Message))
Exit Try
End Try
' while image is acquired
Loop While acquiredImage IsNot Nothing
' close WIA device
device.Close()
' close WIA device manager
deviceManager.Close()
End Using
System.Console.ReadLine()
End Sub