How can I draw lines in WPF inkCanvas with sequence of PNGs - wpf

Question

I was trying to make a method to draw some arrowheads from a PNG image with transparency.
While I moving mouse, the application will be plot that png along the path.
What is the way to make that?
Another form I was wondering is creating a polygnon shape. I was tryed draw the shape (triangle) when enter on mouse down event.
void MainWindow_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
double posX = e.GetPosition(null).X;
double posY = e.GetPosition(null).Y;
double posX1 = posX - (posX / 4);
double posY1 = posY - (posY / 4);
double posX2 = posX + (posX / 4);
double posY2 = posY;
double posX3 = posX - (posX / 4);
double posY3 = posY + (posY - posY / 3);
Polygon p = new Polygon();
p.Stroke = Brushes.Black;
p.Fill = Brushes.LightBlue;
p.StrokeThickness = 1;
p.HorizontalAlignment = HorizontalAlignment.Left;
p.VerticalAlignment = VerticalAlignment.Center;
p.Points = new PointCollection() { new Point(posX1, posY1), new Point(posX2, posY2), new Point(posX3, posY3), new Point(posX1, posY1) };
MyCanvas.Children.Add(p);
}
But still can't click and draw a triangle correctly in mouse (x,y) position.
http://i.stack.imgur.com/bM2i4.png

Answer 1

Here is a quick example.
XAML
<Canvas x:Name='DrawingCanvas'
Margin='30'
Background='LightBlue'
MouseDown='Canvas_MouseDown'
MouseMove='Canvas_MouseMove'
MouseUp='Canvas_MouseUp'>
<Rectangle>
<Rectangle.Fill>
<ImageBrush ImageSource='Arrow.png' x:Name='ArrowBrush'/>
</Rectangle.Fill>
</Rectangle>
</Canvas>
CODE
public partial class MainWindow : Window {
public MainWindow() {
InitializeComponent();
}
private bool _isDrawing = false;
private Point _lastPosition;
const double MIN_MOVEMENT = 60;
private void Canvas_MouseDown(object sender, MouseButtonEventArgs e) {
_isDrawing = true;
_lastPosition = e.GetPosition(DrawingCanvas);
// add the first arrow
AddArrow(_lastPosition);
}
private void Canvas_MouseMove(object sender, MouseEventArgs e) {
if (!_isDrawing)
{
return;
}
var currentPosition = e.GetPosition(DrawingCanvas);
// draw a new image if mouse has traveled minimum distance
if (Math.Abs((currentPosition.X - _lastPosition.X)) > MIN_MOVEMENT ||
Math.Abs((currentPosition.Y - _lastPosition.Y)) > MIN_MOVEMENT)
{
AddArrow(currentPosition);
_lastPosition = e.GetPosition(DrawingCanvas);
}
}
private void AddArrow(Point currentPosition) {
var rect = new Rectangle();
rect.Width = 120;
rect.Height = 120;
rect.Fill = ArrowBrush;
Canvas.SetTop(rect, currentPosition.Y);
Canvas.SetLeft(rect, currentPosition.X);
DrawingCanvas.Children.Add(rect);
}
private void Canvas_MouseUp(object sender, MouseButtonEventArgs e) {
_isDrawing = true;
}
}
Screenshot