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ShowDialogPreview Property

Summary

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

Syntax

C#
VB
C++
public virtual bool ShowDialogPreview { get; set; } 
Public Overridable Property ShowDialogPreview As Boolean 
public: 
virtual property bool ShowDialogPreview { 
   bool get(); 
   void set (    bool ); 
} 

Property Value

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

Example

C#
VB
using Leadtools; 
using Leadtools.MediaFoundation; 
using LeadtoolsMediaFoundationExamples.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, select using your device name here 
      if (capturectrl.VideoDevices["USB"] == null) 
      { 
         throw new Exception("No USB video device available"); 
      } 
 
      capturectrl.VideoDevices["USB"].Selected = true; 
 
      // set the target file and format 
      capturectrl.TargetFile = outFile; 
      capturectrl.TargetFormat = TargetFormatType.MP4; 
 
      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 don't need a complete capture for this example) 
   capturectrl.StopCapture(); 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 19\Media"; 
} 
Imports Leadtools 
Imports Leadtools.MediaFoundation 
Imports LeadtoolsMediaFoundationExamples.Fixtures 
 
Public _result As Boolean = False 
Public _form As New CaptureCtrlForm() 
 
' capture control 
Private capturectrl As CaptureCtrl 
 
' output file 
Private outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_ShowDialogPreviewExample.avi") 
 
Public Sub ShowDialogPreviewExample() 
   ' reference the capture control 
   capturectrl = _form.CaptureCtrl 
 
   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 
 
      ' set the target file and format 
      capturectrl.TargetFile = outFile 
      capturectrl.TargetFormat = TargetFormatType.MP4 
 
      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 generatedExceptionName As COMException 
      _result = False 
   Catch generatedExceptionName As Exception 
      _result = False 
   End Try 
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 19\Media" 
End Class 

Requirements

Target Platforms

Help Version 19.0.2017.10.19
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Leadtools.MediaFoundation Assembly