Отмена получения изображения со сканера изображений WIA

В этом разделе

Вам следует вызвать метод WiaDevice.Close, если вы хотите отменить получение изображения с устройства автоматической подачи документов (АПД) сканера изображений WIA.

Вот пример, демонстрирующий, как отменить текущую синхронную передачу изображения со сканера WIA:

/// <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();
}

VB.NET

''' <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

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