public bool OptimizedHotkey { get; set; }
If true, HotKey processing uses a global system hook. Otherwise, normal hot key processing is performed.
Normally, when a capture function is called, the function enters a loop, and waits for the HotKey specified in nHotKey to be pressed, at which point it performs the capture. This loop can cause the CPU usage indicator to appear maxed out. Specifying the OptimizedHotkey
property to be true
will cause the capture method to return immediately (if a HotKey has been specified in Hotkey
). In this case, a global system HotKey hook is established and used to wait for the HotKey to be pressed. When the HotKey is pressed, the capture is performed and the event handler is called with the results of the capture. Use this option only if the normal behavior is causing your application problems. This option is ignored in Win95/98/Me.
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ScreenCapture;
public void ScreenCaptureEngineExample()
{
// Startup the ScreenCapture
ScreenCaptureEngine.Startup();
// Define a ScreenCaptureEngine class object
ScreenCaptureEngine scEngine = new ScreenCaptureEngine();
// Define an EventHandler for CaptureInformation
scEngine.CaptureInformation += new EventHandler<ScreenCaptureInformationEventArgs>(scEngine_CaptureInformation);
// Define the Help Callback that will run whenever the Help button is pressed on the dialogs
ScreenCaptureHelpCallback helpCallback = new ScreenCaptureHelpCallback(HelpCallback);
// Define ScreenCaptureAreaOptions and fill it using dialog
ScreenCaptureAreaOptions scAreaOptions = ScreenCaptureAreaOptions.Empty;
// Get the default options
scAreaOptions = ScreenCaptureEngine.DefaultCaptureAreaOptions;
// Open the dialog allowing the user to change the values
// NOTE: To fill the structure manually, you can write:
// Cursor drawCursor = Cursors.Cross;
// scAreaOptions.AreaType = ScreenCaptureAreaType.Rectangle;
// scAreaOptions.DrawCursor = drawCursor;
// scAreaOptions.DrawLineColor = Color.Red;
// scAreaOptions.DrawLineStyle = ScreenCaptureAreaLineStyle.Solid;
// scAreaOptions.EllipseHeight = 0;
// scAreaOptions.EllipseWidth = 0;
// scAreaOptions.FillBackgroundColor = Color.Black;
// scAreaOptions.FillForegroundColor = Color.White;
// scAreaOptions.FillPattern = ScreenCaptureAreaFillPattern.Solid;
// scAreaOptions.Flags = ScreenCaptureAreaFlags.ShowInfoWindow;
// scAreaOptions.InfoWindowBounds = new Rectangle(ScreenCaptureAreaOptions.LeftInfoWindowPosition, ScreenCaptureAreaOptions.TopInfoWindowPosition, ScreenCaptureAreaOptions.MediumInfoWindowSize, ScreenCaptureAreaOptions.MediumInfoWindowSize);
// scAreaOptions.TextBackgroundColor = Color.White;
// scAreaOptions.TextForegroundColor = Color.Black;
// scAreaOptions.Zoom = ScreenCaptureAreaZoom.Normal;
scEngine.ShowCaptureAreaOptionsDialog(null, ScreenCaptureDialogFlags.CaptureAreaOptionsContextHelp, scAreaOptions, true, helpCallback);
// Define ScreenCaptureOptions and fill it using dialog
ScreenCaptureOptions scOptions = ScreenCaptureOptions.Empty;
// Set the ScreenCaptureHotKeyCallback, so that it gets called if the hotkey is set in the dialog
ScreenCaptureHotkeyCallback hotkeyCallback = new ScreenCaptureHotkeyCallback(HotKeyCallback);
ScreenCaptureEngine.SetCaptureHotkeyCallback(hotkeyCallback);
// Open the dialog allowing the user to change the values
// NOTE: To fill the structure manually, you can write:
// scOptions.CancelKey = Keys.Escape;
// scOptions.Count = 1;
// scOptions.Cursor = Cursors.Arrow;
// scOptions.Delay = 0;
// scOptions.Hotkey = Keys.F11;
// scOptions.Interval = 0;
// scOptions.OptimizedHotkey = true;
// scOptions.StatusCursor = Cursors.WaitCursor;
scEngine.ShowCaptureOptionsDialog(null, ScreenCaptureDialogFlags.SetCaptureOptionsContextHelp, scOptions, helpCallback);
// Set the Engine's ScreenCaptureOptions
scEngine.CaptureOptions = scOptions;
// Define ScreenCaptureObjectOptions and fill it using dialog
ScreenCaptureObjectOptions scObjectOptions = ScreenCaptureObjectOptions.Empty;
// Get the default Options
scObjectOptions = ScreenCaptureEngine.DefaultCaptureObjectOptions;
// Open the dialog allowing the user to change the values
// NOTE: To fill the structure manually, you can write:
// scObjectOptions.BorderWidth = 2;
// scObjectOptions.EnableKeyboard = true;
// scObjectOptions.Invert = false;
// scObjectOptions.SelectCursor = Cursors.Arrow;
scEngine.ShowCaptureObjectOptionsDialog(null, ScreenCaptureDialogFlags.CaptureObjectOptionsContextHelp, scObjectOptions, true, helpCallback);
// Define ScreenCaptureInformation class object
ScreenCaptureInformation scInformation = null;
// NOTE: After preparing the structures and classes,
// in this place you can insert any Capture method, such as:
// CaptureWindow, CaptureActiveWindow, CaptureActiveClient, CaptureWallpaper,
// CaptureFullScreen, CaptureMenuUnderCursor, CaptureWindowUnderCursor,
// CaptureSelectedObject, CaptureArea, CaptureMouseCursor
// We will Capture an Area of the screen
RasterImage image = scEngine.CaptureArea(scAreaOptions, scInformation);
// To get the number of resources in a EXE file
int iconsCount = scEngine.GetResourcesCount(Path.Combine(LEAD_VARS.ImagesDir, "ExeWithResources.exe"), ScreenCaptureResourceType.Icon);
// Finally, if the Capture is still active, then Stop it
if (scEngine.IsCaptureActive)
scEngine.StopCapture();
// clean up
image.Dispose();
// Shutdown the ScreenCapture
ScreenCaptureEngine.Shutdown();
}
bool HotKeyCallback(Keys key)
{
// Here you can do anything with the pressed key
// we will just show a message box
MessageBox.Show("You pressed the " + key.ToString() + "character.");
return true;
}
void HelpCallback(ScreenCaptureHelpType helpType, ScreenCaptureControlId controlId)
{
// Show a MessageBox mentioning the name of the dialog that called the help,
// and which control ID was requested.
switch (helpType)
{
case ScreenCaptureHelpType.CaptureAreaOptions:
MessageBox.Show("Capture Area Options Dialog Help Button\n" +
"Control Id: " + controlId.ToString() + ".");
break;
case ScreenCaptureHelpType.CaptureFromExe:
MessageBox.Show("Capture From EXE Dialog Help Button\n" +
"Control Id: " + controlId.ToString() + ".");
break;
case ScreenCaptureHelpType.CaptureObjectOptions:
MessageBox.Show("Capture Object Options Dialog Help Button\n" +
"Control Id: " + controlId.ToString() + ".");
break;
case ScreenCaptureHelpType.SetCaptureOptions:
MessageBox.Show("Capture Options Dialog Help Button\n" +
"Control Id: " + controlId.ToString() + ".");
break;
default:
// will never reach here
break;
}
}
void scEngine_CaptureInformation(object sender, ScreenCaptureInformationEventArgs e)
{
// Make sure that the image was captured successfully
Debug.Assert(e.Image != null);
// Define codecs class object to save the image
RasterCodecs codecs = new RasterCodecs();
codecs.ThrowExceptionsOnInvalidImages = true;
// Save the resulted Image
codecs.Save(e.Image, Path.Combine(LEAD_VARS.ImagesDir, "Out_CapturedImage.bmp"), RasterImageFormat.Bmp, 24);
// NOTE: e.Information is a ScreenCaptureInformation structure filled with information
// about the captured image, this information can be used here
// Display a MessageBox with the bounds of the capture area
MessageBox.Show("Captured Area Bounds:\n" +
"Top:" + e.Information.Area.Top.ToString() + "\n" +
"Left:" + e.Information.Area.Left.ToString() + "\n" +
"Right:" + e.Information.Area.Right.ToString() + "\n" +
"Bottom:" + e.Information.Area.Bottom.ToString());
// everything worked fine
e.Cancel = false;
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images";
}