/// <summary>
/// Sent when one or more fingers touches the screen.
/// </summary>
/// <param name="touches">Set containing the touches as objects of type <see cref="T:UIKit.UITouch" />.</param>
/// <param name="evt"><para>The UIEvent that encapsulates all of the touches and the event information.</para>
/// <para tool="nullallowed">This parameter can be <see langword="null" />.</para></param>
/// <remarks><para>
/// The <paramref name="touches" /> set containing all of the touch events.
/// </para>
/// <para>
/// If your application tracks the touches starting with this
/// method, it should also override both the <see cref="M:UIKit.UIResponder.TouchesEnded(Foundation.NSSet,
 UIKit.UIEvent)" /> and <see cref="M:UIKit.UIResponder.TouchesCancelled(Foundation.NSSet,
 UIKit.UIEvent)" /> methods to track the end of
/// the touch processing.
/// </para>
/// <para>
/// UIViews by default only receive a single touch event at
/// once, if you want to receive multiple touches at the same
/// time, set the <see cref="P:UIView.MultipleTouchEnabled" /> property
/// to true.
/// </para>
/// <para>
/// If you only want to handle a single touch, the following idiom can be used:
/// </para>
/// <example>
/// <code lang="C#"><![CDATA[
/// public override void TouchesBegan (NSSet touches, UIEvent evt)
/// {
/// var touch = touches.AnyObject as UITouch;
/// Console.WriteLine (touch);
/// }
/// ]]></code>
/// </example>
/// <para>
/// If you want to handle multiple touches, you can use this idiom:
/// </para>
/// <example>
/// <code lang="C#"><![CDATA[
/// public override void TouchesBegan (NSSet touches, UIEvent evt)
/// {
/// foreach (UITouch touch in touches.ToArray<UITouch> ()){
/// Console.WriteLine (touch);
/// }
/// }
/// ]]></code>
/// </example></remarks>
public override void TouchesBegan(NSSet touches, UIEvent evt)
{
_indexCount++;
var path = new UIBezierPath
{
LineWidth = PenWidth
};
var touch = (UITouch)touches.AnyObject;
_previousPoint = touch.PreviousLocationInView(this);
var newPoint = touch.LocationInView(this);
path.MoveTo(newPoint);
InvokeOnMainThread(SetNeedsDisplay);
_currentPath = path;
var line = new VESLine
{
Path = _currentPath,
Color = CurrentLineColor,
Index = _indexCount
};
_lines.Add(line);
}
public override void TouchesBegan(NSSet touches, UIEvent evt)
{
IndexCount++;
var path = new UIBezierPath
{
LineWidth = PenWidth
};
var touch = (UITouch)touches.AnyObject;
PreviousPoint = touch.PreviousLocationInView(this);
var newPoint = touch.LocationInView(this);
path.MoveTo(newPoint);
InvokeOnMainThread(SetNeedsDisplay);
CurrentPath = path;
var line = new VESLine
{
Path = CurrentPath,
Color = CurrentLineColor,
Index = IndexCount
};
Lines.Add(line);
PointerDown = true;
PointerEvent?.Invoke(this, new PointerEventArgs(PointerEventArgs.
PointerEventType.Down, PreviousPoint.ToPoint(), newPoint.ToPoint(), PointerDown));
}
