如何在鼠标光标处将边距设置到位置元素

Question

I cannot seem to figure out how to set the margins correspond to where the mouse cursor is at.

Sample code:

protected override void OnMouseMove(MouseEventArgs e)
{
  base.OnMouseMove(e);

  Connector connector = this.Template.FindName("PART_Connector", this) as Connector;
  double marginLeft = e.GetPosition(this).X - (connector.Width / 2);
  double marginTop = e.GetPosition(this).Y - (connector.Height / 2);

  connector.Margin = new Thickness(marginLeft, marginTop, 0, 0);
}

The connector positioned using margin is always off from where it is supposed to be.

Any good advice?

---

If I set the margin like this, it will work but the connector is diminished to a single point. I want the connector to be 12x12

marginLeft = e.GetPosition(this).X;
marginTop = e.GetPosition(this).Y;
marginRight = this.DesiredSize.Width - e.GetPosition(this).X;
marginBottom = this.DesiredSize.Height - e.GetPosition(this).Y;

connector.Margin = new Thickness(marginLeft, marginTop, marginRight, marginBottom);

When I rescale the margins to provide the space for the connectors, the connectors just disappear:

marginLeft = e.GetPosition(this).X - (connector.Width / 2);
marginTop = e.GetPosition(this).Y - (connector.Height / 2);
marginRight = this.DesiredSize.Width - e.GetPosition(this).X + (connector.Width / 2);
marginBottom = this.DesiredSize.Height - e.GetPosition(this).Y + (connector.Height / 2);

Appreciate any help here.

Answer 1

OK, I got it fixed. For anyone interested in the solution, the thing to note is you NEED to provide all 4 sides of the margin.

If you only provide left and top, the connector will sort of shift towards the right-bottom portion of the Grid.

Also the fix to accommodate space for the connectors is outlined below:

marginLeft = e.GetPosition(this).X - (connector.Width / 2);
marginTop = e.GetPosition(this).Y - (connector.Height / 2);
marginRight = this.DesiredSize.Width - e.GetPosition(this).X - (connector.Width / 2);
marginBottom = this.DesiredSize.Height - e.GetPosition(this).Y - (connector.Height / 2);

Note marginRight and marginTop need to subtract (And not add) half the size of the connector.