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Acquire Method

Summary

Acquires one or more images from a TWAIN source.

Syntax

C#
VB
C++
public DialogResult Acquire( 
   TwainUserInterfaceFlags flags 
) 
Public Function Acquire( _ 
   ByVal flags As Leadtools.Twain.TwainUserInterfaceFlags _ 
) As DialogResult 
public: 
DialogResult Acquire(  
   Leadtools.Twain.TwainUserInterfaceFlags flags 
)  

Parameters

flags
Indicates whether to display the manufacturer's user interface.

Return Value

One of the DialogResult values. If an error occurs, an exception is thrown.

Remarks

Use the Acquire method to acquire one or more images. Use the AcquireFast method to acquire one or more images and save them to one or more files. The number of pages to acquire can be determined by getting the TWAIN source's capabilities. To change the number of pages to acquire, set the appropriate capability to the desired number. This method will get images from the selected TWAIN source and pass them into an RasterImage object to the AcquirePage event through the TwainAcquirePageEventArgs class. For each image acquired by the currently selected TWAIN source, an AcquirePage event is generated. The Acquire method acquires pages in the following transfer modes:

  • Native - gets the images being scanned into the memory as a whole.
  • Memory Buffered - gets images from the source as strips of data. These strips can be merged to get the whole image.

To set the transfer mode, call SetCapability with the appropriate capability constant. For more information, refer to How to Acquire from the Twain Source.

Example

C#
VB
using Leadtools; 
using Leadtools.Twain; 
 
TwainSession acq_session; 
private void twain_AcquirePage(object sender, TwainAcquirePageEventArgs e) 
{ 
   // get acquired image here 
 
   // call StopFeeder method here if you need to stop the feeder 
   acq_session.StopFeeder(); 
} 
 
public void AcquireExample(IntPtr parent) 
{ 
   acq_session = new TwainSession(); 
   acq_session.Startup(parent, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None); 
 
   acq_session.SelectSource(String.Empty); 
 
   TwainProperties props = acq_session.Properties; 
   TwainDataTransferProperties dataProps = props.DataTransfer; 
   dataProps.FileName = Path.Combine(LEAD_VARS.ImagesDir, "twain.bmp"); 
   dataProps.MemoryBufferSize = dataProps.MemoryBufferSize * 2; 
   props.DataTransfer = dataProps; 
   acq_session.Properties = props; 
   TwainTransferOptions opts = acq_session.TransferOptions; 
 
   acq_session.AcquirePage += new EventHandler<TwainAcquirePageEventArgs>(twain_AcquirePage); 
 
   if (acq_session.Acquire(TwainUserInterfaceFlags.Show) != DialogResult.OK) 
      MessageBox.Show("Error Acquiring From Source"); 
 
   acq_session.Shutdown(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
} 
Imports Leadtools 
Imports Leadtools.Twain 
 
Dim acq_session As TwainSession 
 
Private Sub twain_AcquirePage(ByVal sender As Object, ByVal e As TwainAcquirePageEventArgs) 
   ' get acquired image here 
 
   ' call StopFeeder method here if you need to stop the feeder 
   acq_session.StopFeeder() 
End Sub 
 
Public Sub AcquireExample(ByVal parent As IntPtr) 
   acq_session = New TwainSession() 
   acq_session.Startup(parent, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None) 
 
   acq_session.SelectSource(String.Empty) 
 
   Dim props As TwainProperties = acq_session.Properties 
   Dim dataProps As TwainDataTransferProperties = props.DataTransfer 
   dataProps.FileName = Path.Combine(LEAD_VARS.ImagesDir, "twain.bmp") 
   dataProps.MemoryBufferSize = dataProps.MemoryBufferSize * 2 
   props.DataTransfer = dataProps 
   acq_session.Properties = props 
   Dim opts As TwainTransferOptions = acq_session.TransferOptions 
 
   AddHandler acq_session.AcquirePage, AddressOf twain_AcquirePage 
 
   If acq_session.Acquire(TwainUserInterfaceFlags.Show) <> DialogResult.OK Then 
      MessageBox.Show("Error Acquiring From Source") 
   End If 
 
   acq_session.Shutdown() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
End Class 

Requirements

Target Platforms

Help Version 19.0.2017.10.18
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Leadtools.Twain Assembly