ShowDialogPreview Property

Gets or sets the option to continue to display the preview during a call to the ShowDialog method.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Overridable Property ShowDialogPreview As Boolean

'Usage
 
Dim instance As CaptureCtrl
Dim value As Boolean
 
instance.ShowDialogPreview = value
 
value = instance.ShowDialogPreview

public virtual bool ShowDialogPreview {get; set;}

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

Property Value

true if the preview will continue displaying during ShowDialog calls; false, otherwise.

Example

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

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Imports Leadtools
Imports Leadtools.Multimedia
Imports LeadtoolsMultimediaExamples.Fixtures

Public _result As Boolean = False
Public _form As CaptureCtrlForm = New CaptureCtrlForm()
Public _capturectrl As CaptureCtrl = _form.CaptureCtrl
Public Sub ShowDialogPreviewExample()
   ' reference the capture control
   _capturectrl = _form.CaptureCtrl

   ' output file names
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_ShowDialogPreviewExample.avi")

   Try
      ' set the source video device, select using your device name here
      If _capturectrl.VideoDevices("USB") Is Nothing Then
         Throw New Exception("No USB video device available")
      End If

      _capturectrl.VideoDevices("USB").Selected = True

      ' select video and audio compressors
      _capturectrl.VideoCompressors.Mpeg2.Selected = True

      ' set the target file and format
      _capturectrl.TargetFile = outFile
      _capturectrl.TargetFormat = TargetFormatType.AVI

      _capturectrl.FrameRate = 5 ' 5 frames per second
      _capturectrl.UseFrameRate = True
      _capturectrl.TimeLimit = 10 ' just 10 seconds of capture time
      _capturectrl.UseTimeLimit = True

      If _capturectrl.IsModeAvailable(CaptureMode.Video) Then

         ' set show dialog preview, the preview mode will be enabled when ShowDialog is invoked
         _capturectrl.ShowDialogPreview = True

         ' enable the preview
         _capturectrl.Preview = True

         ' subscribe to the started event
         AddHandler _capturectrl.Started, AddressOf CaptureCtrl_Started

         ' check the video capture dialog properties if available
         If _capturectrl.HasDialog(CaptureDlg.TargetFormat) Then
            _capturectrl.ShowDialog(CaptureDlg.TargetFormat, _form)
         End If

         ' start capture
         _capturectrl.StartCapture(CaptureMode.Video)

         ' get the show dialog preview
         Dim ShowDialogPreview As Boolean = _capturectrl.ShowDialogPreview

         ' set the result to what we expect
         _result = (ShowDialogPreview AndAlso _capturectrl.Preview)
      End If

   Catch e1 As Exception
      _result = False
   End Try

   ' 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.
   Do While _capturectrl.State = CaptureState.Running
      Application.DoEvents()
   Loop
End Sub

Private Sub CaptureCtrl_Started(ByVal sender As Object, ByVal e As EventArgs)
   ' stop the capture (we don't need a complete capture for this example)
   _capturectrl.StopCapture()
End Sub

Public NotInheritable Class LEAD_VARS
Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 18\Media"
End Class

using Leadtools;
using Leadtools.Multimedia;
using LeadtoolsMultimediaExamples.Fixtures;

public bool _result = false;
public CaptureCtrlForm _form = new CaptureCtrlForm();
// capture control
CaptureCtrl capturectrl;

// output file
string outFile = Path.Combine(LEAD_VARS.MediaDir,"CaptureCtrl_ShowDialogPreviewExample.avi");

public void ShowDialogPreviewExample()
{
   // reference the capture control
   capturectrl = _form.CaptureCtrl;

   try
   {
       // set the source video device. use your device's name here
      if (capturectrl.VideoDevices["USB"] == null)
      {
         throw new Exception("No USB video device available");
      }

      capturectrl.VideoDevices["USB"].Selected = true;

      // select video and audio compressors
      capturectrl.VideoCompressors.Mpeg2.Selected = true;

      // set the target file and format
      capturectrl.TargetFile = outFile;
      capturectrl.TargetFormat = TargetFormatType.AVI;

      capturectrl.FrameRate = 5;
      // 5 frames per second
      capturectrl.UseFrameRate = true;
      capturectrl.TimeLimit = 10;
      // just 10 seconds of capture time
      capturectrl.UseTimeLimit = true;


      if (capturectrl.IsModeAvailable(CaptureMode.Video))
      {
         // set show dialog preview, the preview mode will be enabled when ShowDialog is invoked
         capturectrl.ShowDialogPreview = true;

         // enable the preview
         capturectrl.Preview = true;

         // subscribe to the started event
         capturectrl.Started += CaptureCtrl_Started;

         // check the video capture dialog properties, if available
         if (capturectrl.HasDialog(CaptureDlg.TargetFormat))
         {
            capturectrl.ShowDialog(CaptureDlg.TargetFormat, _form);
         }

         // start capture
         capturectrl.StartCapture(CaptureMode.Video);

         // get the show dialog preview
         bool ShowDialogPreview = capturectrl.ShowDialogPreview;

         // set the result to what we expect
         _result = (ShowDialogPreview && capturectrl.Preview);
      }

   }
   catch (COMException)
   {
      _result = false;
   }
   catch (Exception)
   {
      _result = false;
   }
}

void CaptureCtrl_Started(object sender, EventArgs e)
{
   // stop the capture (we do not need a complete capture for this example)
   capturectrl.StopCapture();
}

static class LEAD_VARS
{
public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 18\Media";
}

Requirements

Target Platforms

Reference

CaptureCtrl Class
CaptureCtrl Members