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KeyDownEventArgs Class

Summary

The event argument for the KeyDownEventHandler event handler.

Syntax

C++/CLI

public class KeyDownEventArgs : EventArgs

public ref class KeyDownEventArgs : public System.EventArgs

Remarks

This event occurs when a key is down and a multimedia control has focus.

Example

using Leadtools; 
using Leadtools.MediaFoundation; 
using LeadtoolsMediaFoundationExamples.Fixtures; 
 
 
public bool _result = false; 
public bool _exit = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
 
public void KeyPressesExample() 
{ 
   CaptureCtrl capturectrl = _form.CaptureCtrl; 
   string outFile = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_KeyPressesExample.avi"); 
 
   try 
   { 
      // set a video device, use the name of your device here 
      if (capturectrl.VideoDevices["Analog"] == null) 
         throw new Exception("No Analog capture device available"); 
 
      capturectrl.VideoDevices["Analog"].Selected = true; 
 
      // set an audio device, use the name of your device here 
      capturectrl.AudioDevices["USB"].Selected = true; 
 
      // enable preview 
      capturectrl.Preview = true; 
 
      // set the target output file 
      capturectrl.TargetFile = outFile; 
 
      // subscribe to the key events 
      capturectrl.KeyDown += KeyDown_Helper; 
      capturectrl.KeyUp += KeyUp_Helper; 
      capturectrl.KeyPress += KeyPress_Helper; 
 
      // capture it now! 
      capturectrl.StartCapture(CaptureMode.AutoFramesAndAudio); 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
 
   // 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 (_exit == false) 
      Application.DoEvents(); 
 
   // clean up event handlers 
   capturectrl.KeyDown -= KeyDown_Helper; 
   capturectrl.KeyUp -= KeyUp_Helper; 
   capturectrl.KeyPress -= KeyPress_Helper; 
} 
 
void KeyPress_Helper(object sender, Leadtools.MediaFoundation.KeyPressEventArgs e) 
{ 
   switch ((char)e.keyAscii) 
   { 
      case 'p': 
         // toggle preview mode 
         _form.CaptureCtrl.TogglePreview(); 
         break; 
      case 'f': 
         // toggle full screen mode 
         _form.CaptureCtrl.ToggleFullScreenMode(); 
         break; 
      case 's': 
         // stop the capture and exit 
         _form.CaptureCtrl.StopCapture(); 
         _exit = true; 
         break; 
   } 
 
   // set result 
   _result = true; 
} 
 
void KeyUp_Helper(object sender, KeyUpEventArgs e) 
{ 
   // set result 
   _result = true; 
} 
 
public void KeyDown_Helper(object sender, KeyDownEventArgs e) 
{ 
   // set result 
   _result = true; 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\LEADTOOLS22\Media"; 
}

Requirements

Target Platforms

Reference

KeyDownEventArgs Members

Leadtools.MediaFoundation Namespace

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Help Version 22.0.2022.12.7

Leadtools.MediaFoundation Assembly

Introduction

Getting Started

Namespaces

Leadtools.MediaFoundation Namespace

Leadtools.MediaFoundation.Common Namespace

Assemblies