In This Topic ▼

Preview Property

Summary

Gets or sets the preview enabled state.

Syntax

C++

public virtual bool Preview { get; set; }

Public Overridable Property Preview As Boolean

public: 
virtual property bool Preview { 
   bool get(); 
   void set (    bool ); 
}

Property Value

true if preview is enabled; otherwise, it is false.

Remarks

Assignment can raise an error exception. For more information, refer to the Error Codes.

Example

using Leadtools; 
using Leadtools.MediaFoundation; 
using LeadtoolsMediaFoundationExamples.Fixtures; 
 
public bool _result = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
 
public void IsModeAvailableExample() 
{ 
   // reference the capture control 
   CaptureCtrl capturectrl = _form.CaptureCtrl; 
 
   // output file for processor settings 
   string outFile = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_IsModeAvailableExample.avi"); 
 
   try 
   { 
      // try to find a USB camera 
      if (capturectrl.VideoDevices["USB"] == null) 
         throw new Exception("No USB video device available"); 
 
      capturectrl.VideoDevices["USB"].Selected = true; 
 
      // try to find a USB audio device 
      if (capturectrl.AudioDevices["USB"] == null) 
         throw new Exception("No USB audio device available"); 
 
      capturectrl.AudioDevices["USB"].Selected = true; 
 
      // set the target output file 
      capturectrl.TargetFile = outFile; 
 
      // set the target output format 
      capturectrl.TargetFormat = TargetFormatType.MP4; 
 
      // check if we have can capture video 
      if (capturectrl.IsModeAvailable(CaptureMode.VideoAndAudio)) 
      { 
         capturectrl.FrameRate = 5;       // 5 frames per second  
         capturectrl.UseFrameRate = true; 
         capturectrl.TimeLimit = 10;      // just 10 seconds of capture time 
         capturectrl.UseTimeLimit = true; 
 
         // subscribe to the complete event 
         capturectrl.Complete += new EventHandler(CaptureCtrl_Complete); 
 
         // start the capture process 
         capturectrl.StartCapture(CaptureMode.VideoAndAudio); 
 
         // we'll loop on the state and pump messages for this example. 
         // but you should not need to if running from a Windows Forms application. 
         while (capturectrl.State == CaptureState.Running) 
            Application.DoEvents(); 
      } 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
} 
 
void CaptureCtrl_Complete(object sender, EventArgs e) 
{ 
   _result = true; 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\LEADTOOLS21\Media"; 
}

Imports Leadtools 
Imports Leadtools.MediaFoundation 
Imports LeadtoolsMediaFoundationExamples.Fixtures 
 
Public _result As Boolean = False 
Public _form As New CaptureCtrlForm() 
 
Public Sub IsModeAvailableExample() 
   ' reference the capture control 
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl 
 
   ' output file for processor settings 
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_IsModeAvailableExample.avi") 
 
   Try 
      ' try to find a USB camera 
      If capturectrl.VideoDevices("USB") Is Nothing Then 
         Throw New Exception("No USB video device available") 
      End If 
 
      capturectrl.VideoDevices("USB").Selected = True 
 
      ' try to find a USB audio device 
      If capturectrl.AudioDevices("USB") Is Nothing Then 
         Throw New Exception("No USB audio device available") 
      End If 
 
      capturectrl.AudioDevices("USB").Selected = True 
 
      ' set the target output file 
      capturectrl.TargetFile = outFile 
 
      ' set the target output format 
      capturectrl.TargetFormat = TargetFormatType.MP4 
 
      ' check if we have can capture video 
      If capturectrl.IsModeAvailable(CaptureMode.VideoAndAudio) Then 
         capturectrl.FrameRate = 5 
         ' 5 frames per second  
         capturectrl.UseFrameRate = True 
         capturectrl.TimeLimit = 10 
         ' just 10 seconds of capture time 
         capturectrl.UseTimeLimit = True 
 
         ' subscribe to the complete event 
         AddHandler capturectrl.Complete, AddressOf CaptureCtrl_Complete 
 
         ' start the capture process 
         capturectrl.StartCapture(CaptureMode.VideoAndAudio) 
 
         ' we'll loop on the state and pump messages for this example. 
         ' but you should not need to if running from a Windows Forms application. 
         While capturectrl.State = CaptureState.Running 
            Application.DoEvents() 
         End While 
      End If 
   Catch generatedExceptionName As Exception 
      _result = False 
   End Try 
End Sub 
 
Private Sub CaptureCtrl_Complete(ByVal sender As Object, ByVal e As EventArgs) 
   _result = True 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const MediaDir As String = "C:\LEADTOOLS21\Media" 
End Class

Requirements

Target Platforms

Reference

CaptureCtrl Class

CaptureCtrl Members

Download our FREE evaluation

Help Version 21.0.2021.7.2

Leadtools.MediaFoundation Assembly

Introduction

Getting Started

Namespaces

Leadtools.MediaFoundation Namespace

Leadtools.MediaFoundation.Common Namespace

Assemblies