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Twain Acquisition for Microsoft® .NET

Developer's Guide for Atalasoft DotTwain 2.1

Atalasoft DotTwain 2.1 Developer's Guide | 1

© Copyright 2000 - 2006, Atalasoft, Inc.

Table Of Contents

1. Introduction 3

2. Overview 4

3. Getting Started 5-7

4. Deployment 8

5. License Agreement 9-12

6. History 13

6.1. What's new in DotTwain 2.1 13

6.2. What's New in DotTwain 2.0 13-14

7. How To's 15

7.1. Acquire a Select Region of the Device 15-16

7.2. Acquire Directly to a File 16-18

7.3. Detecting a Camera Device 18

7.4. Embed in Internet Explorer 18-19

7.5. Upload an Image to a Server 19-21



Atalasoft DotTwain 2.1 is a 100% Managed .NET Windows Form component with fast capturing of digital images from scanners, cameras, and other devices supporting TWAIN. It utilizes the improvements of the TWAIN 1.9 specifications for ultra fast scanning. It works with a .NET Bitmap object and has no dependencies other then the .NET Framework. This is intended for a small footprint "no-touch" deployment over the web or if you need scanning abilities without Atalasoft dotImage.

1.1 Supported Features

l Full context sensitive help and documentation.

l Object-oriented design; a TWAIN extension to the .NET Framework.

l Create a custom interface to scan images, or use the default TWAIN interface.

l Automatic Document Feeder support, with full control of the feeder operations.

l Support for duplex scanning.

l File system support for navigating the internal device memory.

l Acquire images directly to file utilizing compression algorithms supported by the device.

l Select a region of the scanning bed to be acquired with frame support.

l Upload a scanned image to a server with the built in HTTP Post class.

l Supports Web Deployment; Embed into an Internet Explorer Browser or deploy as a WinForms application

l Simplified automatic capture allowing the device to quickly capture multiple images for later acquisition.

l Imprinter/Endorser methods allowing a text string ito be stamped onto the acquired image during the acquisition.

l Barcode/Patchcode classes to access barcode and patchcode recognition abilities of the device.

l A low-level class allowing even more control over the scanning session for advanced users.

l Extensible to allow custom driver capabilities access.

l Image dataset support enables acquisition of specific images from a camera in a single operation.

l Quickly find out what capabilities, compression modes, frame sizes, resolutions and more, are supported by a device.

l Over 80 properties and 50 methods to give total control over the image acquisition.

DotTwain has been tested on many industry leading document scanners including those from Kodak, Fujitsu, Panasonic, Canon, Visioneer, Xerox, and Bell & Howell.

1 Introduction



This topic introduces you to the basic classes to give you a general understanding of Atalasoft DotTwain and how to begin using it.

2.1 Acquiring Images

Acquisition

The Acquisition object is the primary class in DotTwain. This component can be dropped onto a form after adding it to the toolbox, or be instantiated directly. For adding standard image acquisition capabilities to an application, this is the only class that is needed. For more control over the acquire process, this class contains a collection of Device objects that controls numerous properties used for the image acquisition.

TwainController

The TwainController object is a low-level TWAIN class used by the Device and Acquisition objects. Using this class can provide more direct access to TWAIN and allows custom driver capabilities to be used. This class can be created as a standalone object or can be accessed through the Device.Controllerproperty. Only advanced users with knowledge of the TWAIN specification should attempt using this class.

Device

The Device object gives full access to a TWAIN compatible source on the system. It is used to open a connection to the device, get and set properties, and then acquire one or more images. Because this class represents a system device resource, you cannot create an instance of it. An instance to a Device object can be obtained by calling ShowSelectSource, or from the Devices collection in the Acquisition object.

DeviceCollection

The DeviceCollection holds a read-only collection of Device objects which represent all of the TWAIN compatible system resources. From this collection, the system default device can be obtained, or a suitable device can be found by enumerating through the collection. Should system conditions change, such as a device being unplugged, the ScanForChanges method is used to recreate this collection.

2.2 Document Feeder Control

DocumentFeeder

Many scanners have an automatic document feeder (ADF) allowing multiple images to be scanned in a single process. The DocumentFeeder class gives full control over the feeder, as well as being able to enable or disable its use.

2.3 Navigating Files in a Camera

FileSystem

The FileSystem object can be used to walk through the file system structure in a TWAIN compatible camera's internal storage or used to create, delete, copy and rename files and directories directly in the camera. Images are acquired from the camera by using the SetImageDataset method in the Deviceobject, then calling the Acquire method of the same Device object.

2 Overview



This topic explains how to get started using Atalasoft DotTwain in your applications.

3.1 Adding Atalasoft DotTwain to the Toolbox

To add the Acquisition component to the toolbox:

1. Click Tools | Customize Toolbox on the Visual Studio .NET menu.

2. Make sure the .NET Framework Components tab is selected, and find the Atalasoft.Twain namespace.

3. Select the checkbox that corresponds to the Acquisition component.

4. Click OK.

Acquisition is now included in your toolbox and you can double-click the control to add it to your form.

3.2 Setting Application Information

After you add the Acquisition control to your form, you should set the ApplicationIdentity properties which will be used by the TWAIN driver. If you don't set these properties, default values will be used.

Setting the following properties is optional but recommended:

l Country

l Info

l Language

l Manufacturer

l ProductFamily

l ProductName

l VersionMajor

l VersionMinor

There is also a Parent property which is used by TWAIN when displaying dialogs and acquiring images. You must set the Parent property to the parent form or control in order to acquire images.

3.3 Modal Acquisition

By default, the Acquire method is asynchronous and will return before scanning has completed. This method can be made to work in a synchronous manner by using the Device object and setting its ModalAcquire property to true. An example of this is shown in the sample code below.

[C#]this.device = this.acquisition.Devices.Default;this.device.ModalAcquire = true;this.device.Acquire();[Visual Basic]Me.device = Me.acquisition.Devices.DefaultMe.device.ModalAcquire = TrueMe.device.Acquire()

3.4 Setting Up Events

For acquiring images events need to be used. When an image is acquired, the ImageAcquired event fires providing an AcquireEventArgs object containing the image. At the very least, the ImageAcquired event should be handled, but it's recommended that the AcquireCanceled and AcquireFinished events also be handled. The following code shows how the image is handled

[C#]this.acquisition.ImageAcquired += new ImageAcquiredEventHandler(OnImageAcquired);private void OnImageAcquired(object sender, AcquireEventArgs e){

// If the image exists, load it into a WorkspaceViewer control.if (e.Image != null){

this.viewer.Images.Add(AtalaImage.FromBitmap(e.Image));

3 Getting Started



e.Image.Dispose();}

}[Visual Basic]Private Sub OnImageAcquired(ByVal sender As System.Object, ByVal e As Atalasoft.Twain.AcquireEventArgs) Handles acquisition.ImageAcquired

' If the image exists, load it into a WorkspaceViewer control.If Not e.Image Is Nothing Then

Me.viewer.Images.Add(AtalaImage.FromBitmap(e.Image))e.Image.Dispose()

End IfEnd Sub

3.5 Showing the "Select Source" dialog

Your application should allow users to select which TWAIN device they want to use. This is accomplished by displaying the "Select Source" dialog using the ShowSelectSource method. The code below assumes the Acquisition component is named "acquisition".

[C#]Device device = this.acquisition.ShowSelectSource();[Visual Basic]Dim device As Device = Me.acquisition.ShowSelectSource()

ShowSelectSource returns a Device object or null (Nothing in VB) if the user canceled the dialog. When a user selects a device in this dialog, it becomes the system default device.

3.6 Getting and Setting Properties

To get or set a device property, a connection to the device must be opened by using the Open method. Whenever the Open method is invoked, the Close method must be invoked to close the connection. Closing a connection will reset all of the device properties to their default values and therefore should be closed after the image has been acquired or all desired properties have. Open and Close only need to be used when getting or setting properties on the device.

[C#]device.Open();ResolutionData res = device.Resolution;int bitDepth = device.BitDepth;device.Close();

[Visual Basic]device.Open()Dim res As ResolutionData = device.ResolutionDim bitDepth As Integer = device.BitDepthdevice.Close()

The above code opens a connection to the device in order to retrieve the default Resolution and BitDepthvalues of the device, then closes the connection. This technique may be useful if you are looking for a device in the DeviceCollection with specific default properties or capabilities. See QueryCapability for more information.

3.7 Acquiring an Image

You can acquire an image through the Acquisition object or from a Device object. If you don't need to get or set any properties, the easiest method is to use the Acquire from the Acquisition object, which will use the system default device. This is the method shown below:

[C#]this.acquisition.Acquire();

[Visual Basic]Me.acquisition.Acquire()

You can optionally hide the device interface and/or ask that the device save the acquired image directly to file.

Once the image has been acquired, the ImageAcquired event will fire and provide an AcquireEventArgsobject containing the image. If you invoked the Open method in order to set properties before the acquire,



you should invoke the Close method in the AcquireFinished event to close the device.



4.1 Windows Based Deployment

To distribute Atalasoft Twain for .NET with your .NET application you simple need to include Atalasoft.DotTwain.dll and Atalasoft.Shared.dll in the same folder as the assembly that references it. Make sure that the version you distribute is the version your assembly was compiled with.

4.2 Web Based Deployment

Also known as "no-touch install" this is a method of deploying a .NET assembly over the internet or intranet. Because Atalasoft DotTwain is a 100% managed code assembly this is possible however it does require the correct .NET security policy to be set. There are two methods of deploying over the internet. The first method is deploying the full Windows Form application as an EXE. This can be done with a strong name permission of the Atalasoft.DotTwain.dll assembly. The other method is embedding DotTwain into Internet Explorer via a UserControl. See our ASP.NET Demo for an example and the Deploy over the Internet (Section 7.4) topic for more details.

4 Deployment



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5 License Agreement



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Atalasoft DotTwain 2.1 adds new functionality and features as outlined below.

6.1.1 New Features

l An AutoDiscardBlankPages property was added. For drivers that support this feature it will automatically skip scanned pages it believes to be blank.

l Added LoadXmlParameters and SaveXmlParameters methods. Theses methods can be used to save and restore device settings without the driver needing to support any special capability.

6.1.2 Changes

l DotTwain now requires distribution of Atalasoft.Shared.dll. Any project that uses DotTwain should also reference this new assembly.

Atalasoft DotTwain 2.0 adds new functionality, features, and add-ons as outlined below.

6.2.1 New Features

l A low-level class named TwainController has been added to provide more control over the TWAIN session, allowing the developer to obtain more information directly from TWAIN while maintaining an easy to use interface. The TwainController can be used as a standalone object or accessed from the Device.Controller property to allow a mix of upper and lower-level coding.

l Added over 20 methods to the Device object that provide information on the values supported for specific capabilities.

l Added Barcode and Patchcode properties to the Device object that allow access to barcode and patchcode detection features supported by the device.

l Added support for buffered memory transfer.

l Added SaveParameters and LoadParameters methods that can be used to store device settings between sessions. The device must support the TwainTriplet.CustomDSDataSet capability to use these methods.

l Added Enable and Disable methods to the Device object that are used to keep the scanner interface displayed between scans.

l Added a BeforeTwainDataTransfer event that will provide general information on the image about to be scanned. This will allow you to cancel the scan if the image parameters do not meet your requirements.

l Added the ability to handle processing of the acquired data. This is convenient if the data is a format not supported directly in DotTwain.

l Added the ability to access custom driver properties that are not part of the TWAIN specification by using the TwainController and ITwainDataStructure interface for defining these capabilities.

l Added a CanOpen method which can be used to determine if a call to the Open method will succeed.

l Added a LastReturnCode property and GetConditionCode method which is used to provide more detailed information should setting a Device property fail to change its value.

l Added an ImageLayout property as an alternative to the Frame property for devices that do not support the DeviceCapability.ICAP_FRAMES.

l Added the ability to specify multiple frames when acquiring, provided the device has this capability.

6.2.2 Changes

l Properties in the Acquisition object, such as Manufacturer, Country and Language, have been combined

6 History

6.1 What's new in DotTwain 2.1

6.2 What's New in DotTwain 2.0



into a TwainIdentity class. The Acquisition.ApplicationIdentity property now holds these values for your application and Device.Identity contains this information on the device.

l The DeviceCapabilities enumeration has changed to match the names in the TWAIN specification.

l Device.GetSupportedCapabilities now returns an array of DeviceCapability instead of string.

l Renamed ImprinterEndorserTypes to ImprinterEndorserType and the None enumeration value has been removed.

l Device.GetSupportedPrinters now returns an array of ImprinterEndorserType.

l Renamed TwainDataImageInfoArgs to TwainDataImageInfoEventArgs.

l TwainResolution now uses float (Single) values instead of double.

l The following property types have been changed:

¡ Device.Brightness changed from Int32 to Single.

¡ Device.Contrast changed from Int32 to Single.

¡ Device.Gamma changed from Double to Single.

¡ Device.MinimumHeight changed from Double to Single.

¡ Device.MinimumWidth changed from Double to Single.

¡ Device.PhysicalHeight changed from Double to Single.

¡ Device.PhysicalWidth changed from Double to Single.

¡ Device.Rotation changed from Double to Single.

¡ Device.Shadow changed from Int32 to Single.

¡ Device.Threshold changed from Int32 to Single.

l AcquireModal has been deprecated. Instead, set the Device.ModalAcquire property to True and use the Acquire method. This means you must handle the ImageAcquired event to get the image.

l The Acquire overload taking two Boolean parameters (hideInterface and saveToFile) has been deprecated. Instead, set the Device.HideInterface and Device.TransferMethod properties to control these parameters.

l Acquisition.ShowSelectSource will now return null (Nothing) if the dialog is canceled.

6.2.3 Inspector TWAIN

Inspector TWAIN is an application which uses DotTwain 2.0 to inspect TWAIN driver capabilities and optionally perform scan tests. An XML file containing the test result is generated in the same folder as the Inspector TWAIN application. Clicking the ‘Submit’ button will send the result to Atalasoft and allow us to gather information about these scanners. This information will help us locate issues with drivers and get a feel for which scanners are most popular.



Some scanners allow you to select a rectangular region of the scanning bed that you want to acquire. If you know that you only need a specific area or page size, this can greatly increase your scanning speed. This region is represented by the Frame property of the Device object. Another method is to use the ImageLayout property; in some cases a driver will only support one or the other.

The Frame values are in Units, so you need to be aware of the Units property before setting the Framesize.

The code examples below assume you have already opened a connection to the device by calling the Openmethod.

7.1.1 Acquiring a Specific Size

If you only need to specify a standard region size, you can use the FrameSize property instead.

[C#]// Make sure the FrameSize property is supported by the device.if (this.device.QueryCapability(DeviceCapability.FrameSize, true){

// Get a list of supported frames and choose the one that fits your needs.StaticFrameType[] frames = this.device.GetSupportedFrameSizes();foreach (StaticFrameType frame in frames) {

if (frame == StaticFrameType.LetterUS){

this.device.FrameSize = frame;break;

}}

}

[Visual Basic]' Make sure the FrameSize property is supported by the device.If Me.device.QueryCapability(DeviceCapability.FrameSize,True) Then

' Get a list of supported frames and choose the one that fits your needs. Dim frames() As StaticFrameType = Me.device.GetSupportedFrameSizes() Dim frame As StaticFrameTypeFor Each frame In frames

If frame = StaticFrameType.LetterUS ThenMe.device.FrameSize = frame Exit For

End IfNext

End If

7.1.2 Acquiring any Size and Position

If you need a more control over the size and position, or if the device doesn't support the FrameSizeproperty, you can attempt to set the acquisition area using the Frame property instead.

[C#]// Try to use Inches.this.device.Units = UnitType.Inches;

if (this.device.Units != UnitType.Inches) return;this.device.Frame = new System.Drawing.RectangleF(0, 0, 8.5, 11); [Visual Basic]' Try to use Inches.Me.device.Units = UnitType.Inches

7 How To's

7.1 Acquire a Select Region of the Device



If Me.device.Units <> UnitType.Inches ThenReturn

End IfMe.device.Frame = New System.Drawing.RectangleF(0, 0, 8.5, 11)

Some devices allow to you acquire an image and save it directly to a file, instead of returning the image data. While the overall process is simple, there are a few steps you have to take.

7.2.1 Checking for Device Capabilities

The first thing you should do is test the device to make sure it is capable of saving a file. If so, you then need to negotiate the type of file to save.

[C#]// Open a connection to the device.this.device.Open();this.device.TransferMethod = TwainTransferMethod.TWSX_NATIVE;

// See if the device supports file transfer.TwainTransferMethod[] methods = this.device.GetSupportedTransferMethods();foreach (TwainTransferMethod method in methods){

if (method == TwainTransferMethod.TWSX_FILE2){

// Use TWSX_FILE2 when possible.this.device.TransferMethod = method;break;

}

if (method == TwainTransferMethod.TWSX_FILE)this.device.TransferMethod = method;

}

// If it's not supported tell stop.if (this.device.TransferMethod == TwainTransferMethod.TWSX_NATIVE){

// Close the connection. this.device.Close(); MessageBox.Show("The current device does not support saving directly to a file.");return;

}

// Find out which file types the device can save to. SourceImageFormat[] formats = this.device.GetSupportedImageFormats();

// We want to save the image as a TIFF. foreach (SourceImageFormat format in formats) {

if (format == SourceImageFormat.Tiff) {

// TIFF is supported, so set the FileFormat. this.device.FileFormat = format;

// Now lets try to use Group4 or Group3 compression. // We could use GetSupportedCompressionModes, but we // will simply try setting the Compression property instead. this.device.Compression = CompressionMode.Group4; if (this.device.Compression != CompressionMode.Group4)

this.device.Compression = CompressionMode.Group3;

break;}

7.2 Acquire Directly to a File



}

// Start the acquire process, using the device's interface. this.device.Acquire();

[Visual Basic]' Open a connection to the device.Me.device.Open()Me.device.TransferMethod = TwainTransferMethod.TWSX_NATIVE

' See if the device supports file transfer.Dim methods() As TwainTransferMethod = Me.device.GetSupportedTransferMethods() Dim method As TwainTransferMethodFor Each method In methods

If method = TwainTransferMethod.TWSX_FILE2 Then' Use TWSX_FILE2 when possible.Me.device.TransferMethod = methodExit For

End If

If method = TwainTransferMethod.TWSX_FILE ThenMe.device.TransferMethod = method

End IfNext

' If it's not supported tell stop.If Me.device.TransferMethod = TwainTransferMethod.TWSX_NATIVE Then

' Close the connection. Me.device.Close() MessageBox.Show("The current device does not support saving directly to a file.")Return

End If

' Find out which file types the device can save to. Dim formats() As SourceImageFormat = Me.device.GetSupportedImageFormats()

' We want to save the image as a TIFF. Dim format As SourceImageFormatFor Each format In formats

If format = SourceImageFormat.Tiff Then' TIFF is supported, so set the FileFormat. Me.device.FileFormat = format

' Now lets try to use Group4 or Group3 compression. ' We could use GetSupportedCompressionModes, but we ' will simply try setting the Compression property instead. Me.device.Compression = CompressionMode.Group4 If Me.device.Compression <> CompressionMode.Group4 Then

Me.device.Compression = CompressionMode.Group3End If

Exit ForEnd If

Next

' Start the acquire process, using the device's interface. Me.device.Acquire()

7.2.2 Setting Filenames

During the acquire process, the FileTransfer event will be raised just before each file is acquired. You need to set the FileName property of the FileTransferEventArgs object passed into the event. This will tell the device where the file should be saved.

[C#]private void OnFileTransfer(object sender, FileTransferEventArgs e){



e.FileName = @"C:\TwainImages\whatever.tif";}

7.2.3 Closing the Connection

When all of the images have been acquired, the AcquireFinished event will be raised. You should close the connection here.

[C#]private void OnAcquireFinished(object sender, System.EventArgs e){

this.device.Close();}

There may be times when you want to only use a camera device. Unfortunately, TWAIN doesn't provide a direct way of knowing what type of device is being used. However, you can do a little investigating to help pick out a camera from a scanner.

Using the QueryCapability method, you can find out if a device supports certain features that are normally only supported by camera devices. Below is a list of capabilities you can check:

l Flash

l Flash2

l ExposureTime

l BatteryMinutes

l BatteryPercentage

l CameraPreviewInterface

l PowerSupply

l ZoomFactor

This topic will demonstrates using features built into the .NET Framework to deploy Atalasoft DotTwain over the internet embedded in Internet Explorer.

7.4.1 Embedding DotTwain into Internet Explorer

DotTwain can be used from a WinForms UserControl. This is the preferred method when web deploying as it provides more functionality than using DotTwain directly from Javascript. Once the UserControl has been created (see our TwainControl demo included in the installation for an example), simple HTML code will cause the assembly to be downloaded and installed into the download cache of the client's system. This is similar the adding an ActiveX component to a web page. Here is an example:

<object id="Twain" classid="http://siteaddress/MyControl.dll#MyScanObject" width="100" height="100"></object>

As you can see, the only real difference is the classid parameter. The first part of that parameter tells the browser where the assembly is located. If you don't use a path, the assembly is assumed to be in the same folder as the web page. This is followed by a hash (#) symbol and the name of the class object you want to

7.3 Detecting a Camera Device

7.4 Embed in Internet Explorer



create, which in this case is MyScanObject.

7.4.2 Security Issues

Before you can use DotTwain in Internet Explorer, your client must have setup Site permissions to allow the assembly to execute. This can be done using the Microsoft .NET Framework Configuration tool which is installed with the .NET Framework. You may also be able to create an MSI file which will do this automatically. Enterprises can setup a Group Policy to automatically set this up as users log-in to their systems.

Normally, you would add a new group to the Machine - All Code section with points to your domain with Full Permission. This will grant all assemblies coming from the domain full access to the client's resources.

7.4.3 Licensing Web Deployment

The Atalasoft.DotTwain.lic file must be in the same folder on your server as the assembly. Your evaluation or normal DotTwain license will work with installations on "localhost" but not in a deployed server environment. You will have to request a special license file in order to use DotTwain on your server (one is available per purchase). This license is tied to the DNS or IP address of the deployment server. Please send your licensing request to [email protected].

7.4.4 Debugging Assembly Issues

If you're getting an error when trying to use an assembly method, it's most likely because the assembly object wasn't created due to security issues. One thing you can do is check the exception logs created by Internet Explorer. You can find them in the Temporary Internet Files folder named "?FusionBindError!name=Atalasoft.DotTwain.dll Atalasoft.Twain.Acquisition". Drag this file to Internet Explorer to read the exception and trace log. If you use the HttpPost object, it will create it's own exception file as well.

There may be times when you want to send a scanned image to a web server. The HttpPost class was written for this specific purpose.

7.5.1 Uploading the image

Below is an example which sends a single image, along with a username and password to identify the person sending the image, to a server.

[C#]private void UploadImage(System.Drawing.Bitmap image){// Create an instance of HttpPost and use the default image encoder.Atalasoft.Twain.HttpPost post = new Atalasoft.Twain.HttpPost(); // Add the image to the form data collection.post.FormData.Add("image1", image, "filename.png"); // Add data to identify the user posting the image.post.FormData.Add("username", user);post.FormData.Add("password", password); // Post the form data to the server and retrieve a return value.string ret = post.PostData("http://www.website.com/postImage.aspx");}

[Visual Basic]Private Sub UploadImage(ByVal image As System.Drawing.Bitmap)' Create an instance of HttpPost and use the default image encoder.Dim post As Atalasoft.Twain.HttpPost = New Atalasoft.Twain.HttpPost() ' Add the image to the form data collection.post.FormData.Add("image1", image, "filename.png") ' Add data to identify the user posting the image.post.FormData.Add("username", user)

7.5 Upload an Image to a Server



post.FormData.Add("password", password) ' Post the form data to the server and retrieve a return value.Dim ret As String = post.PostData("http://www.website.com/postImage.aspx") End Sub

The first part of the code creates an instance of HttpPost and uses the default image format, which is PNG. The image format determines the file type of the image when saved on the server.

We then add the image to the FormDataCollection, which includes the field name, image and filename for the image. It's best to think of HttpPost as an HTML FORM object. The FormData represents the FORM elements; in this case a FILE input box. You can update multiple images by simply adding more to the collection. Just be sure each has a unique field name.

Next we add the username and password of the person sending this image. In may cases, you will want to send additional information along with the image in order to perform a specific action on the server. In terms of an HTML FORM, this would be a TEXTBOX field.

Finally, the FormData is sent to the server using the PostData method. The return value of PostData is a string that is sent back from the server. Normally this is used to confirm the success of the call.

7.5.2 Saving the image

Once the image has been sent, we save the image to the server using ASP.NET. This code could be modified to store the image in a database instead.

[C#]private void Page_Load(object sender, System.EventArgs e){

if (Request.Files.Count == 0) return;

// Save the file to the server.string fileName = System.IO.Path.GetFileName(Request.Files[0].FileName);Request.Files[0].SaveAs(GetNewFileName(fileName));

// Return the path to this file.Response.Clear();Response.Write("success");Response.End();

}

private string GetNewFileName(string fileName){

// Create a unique filename.string path = Server.MapPath("./images") + "\\" + Session.SessionID + fileName;return path;

}

[Visual Basic]Private Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

If Request.Files.Count = 0 ThenReturn

End If

' Save the file to the server.Dim fileName As String = System.IO.Path.GetFileName(Request.Files(0).FileName) Request.Files(0).SaveAs(GetNewFileName(fileName))

' Return the path to this file.Response.Clear()Response.Write("success")Response.End()

End Sub Private Function GetNewFileName(ByVal fileName As String) As String

' Create a unique filename.Dim path As String = Server.MapPath("./images") + "\\" + Session.SessionID + fileName Return path



End Function

In the code above, we use the SaveAs method to save the image to the server. Notice that we get the FileName property of the posted file. This is the same value that was passed to the FormData.Add method when you added the image.

The data written to the Response object is what gets returned by the PostData method. It's a good idea to use the Response.Clear method before adding your return value. Here we just return "success".



Develop

Documents

twain acquisition

introductionatalasoft

image acquisition

atalasoft dotimage

camera device

acquisition of specific

image dataset support

fast scanning