Creating A Continuous Action During A Windows Form Mouse Event

Question

When I put a button on a form in C#, Visual Studio 2005, and have an action triggered by a button event, such as MouseHover or MouseDown, then the event triggers a single call to the function which defines the action despite the fact that I may continue to hover or keep the left button down. In this case I am trying to move a graphical object by rotating or translating it. I don't want to continue to click the mouse in order to get a repeated call to the transforming function, just keep the mouse hovering or hold the button down. What maintains the action until I cease my own action?

Answer 1

Set a flag on MouseEnter and keep doing the action while the flag remains true. Set the flag to false on MouseLeave.

Answer 2

In your case you need to use a combination of the events MouseDown, MouseMove and MouseUp.

Here a small simplified example to start:

private void OnMouseDown(object sender, EventArgs e)
{
   //hit test to check if the mouse pointer is on a graphical object
   _myHitObject = the_selected_object
}

private void OnMouseMove(object sender, EventArgs e)
{
   if(_myHitObject != null)
       //do your action relative to the mouse movements.
}

private void OnMouseUp(object sender, EventArgs e)
{
    _myHitObject = null;
}

Answer 3

The solution is to use DoEvents() which allows for the MouseLeave event to be noted and the class variable "more" to be changed:

private void MouseEnter_ZoomIn(object sender, EventArgs e)

{

 more = true;

 while (more == true)

 {
    c1Chart3D1.ChartArea.View.ViewportScale *= ZoomMultiple;
    Application.DoEvents();

 }

} // MOUSEENTER_ZOOMIN()

//-------------------------------------

private void MouseLeave_Stop(object sender, EventArgs e)

{

 more = false;

}