←Select platform

IsVideoPreviewAvailable Method

Summary
Determines whether there is an available video preview.

Syntax
C#
C++/CLI
Python
public bool IsVideoPreviewAvailable() 
public: 
bool IsVideoPreviewAvailable();  
def IsVideoPreviewAvailable(self): 

Return Value

true if the video preview is started; otherwise, false.

Remarks

This function is used to determine whether the video preview has started. Start the video preview by calling the WiaSession.StartVideoPreview method.

Example
C#
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Wia; 
 
 
       
public void IsVideoPreviewAvailableExample(IntPtr parent) 
{ 
   if (!WiaSession.IsAvailable(WiaVersion.Version1)) 
   { 
      Console.WriteLine("WIA version 1.0 not installed."); 
      return; 
   } 
 
   WiaSession wiaSession = new WiaSession(); 
   wiaSession.Startup(WiaVersion.Version1); 
 
   DialogResult res = wiaSession.SelectDeviceDlg(parent, WiaDeviceType.StreamingVideo, WiaSelectSourceFlags.NoDefault); 
   if (res != DialogResult.OK) 
   { 
      Console.WriteLine("Error selecting WIA device."); 
      wiaSession.Shutdown(); 
      return; 
   } 
 
   // start the video preview 
   wiaSession.StartVideoPreview(parent, false); 
 
   // determine whether a video preview is available 
   bool available = wiaSession.IsVideoPreviewAvailable(); 
   if (!available) 
   { 
      Console.WriteLine("No streaming video available."); 
      wiaSession.EndVideoPreview(); 
      wiaSession.Shutdown(); 
      return; 
   } 
 
   // Resize the video preview area to fit the parent window. 
   // I am calling this resize function here only for demonstration purposes, but you 
   // should call it in your window resize event. 
   wiaSession.ResizeVideoPreview(true); 
 
   // acquire an image from the video source. 
   string takenPictureFileName = wiaSession.AcquireImageFromVideo(); 
 
   string strMsg = String.Format("Acquired image was saved to the following path:\n{0}", takenPictureFileName); 
   Console.WriteLine(strMsg); 
 
   wiaSession.EndVideoPreview(); 
   wiaSession.Shutdown(); 
} 
Requirements

Target Platforms

Help Version 22.0.2023.3.31
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Leadtools.Wia Assembly

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.