1. FillSolidRect fills dropdown combo box area and not CView client area
My application overrides the CView::OnEraseBkgnd function and simply returns a value of TRUE (i.e. my application is responsible for clearing the client area each time the display is refreshed). To clear the screen, I call CDC::FileSolidRect from within the CView::OnDraw function. This works well until I click on a combox box in the toolbar. After making a selection from the combo-box, it appears that FileSolidRect only clears the area that was occupied by the drop down list box associated with the combox-box and not the client area in the CView. It is almost as if the device context is associated with combo box and not the CView. The problem is corrected the next time that CView::OnDraw is called. But each time I click on the combo box, the problem reoccurs. If this statement of the problem is not to vague, does anyone have an idea of what might be happening and how to resolve it? Many thanks, Ian
2. drawing a rectangle with CDC
3. Draw rounded rectangle inside a specific area
Hi, how can i draw a rounded rectange, with a border within a specified area? i.e. if i have a Rectangle with width and height of 100, how can i draw a rectange with 2 pixel border inside of the original one? (the current attempts all draw the border just outside of the original rectangle). At the moment im using the following code, but it allows the rectangle to grow - which i definately dont want! m_edgePath = new GraphicsPath(); Point topLeft = new Point(this.ClientRectangle.Left + m_borderWidth, this.ClientRectangle.Top + m_borderWidth); Point topRight = new Point(this.ClientRectangle.Right - m_curveSize.Width - m_borderWidth, this.ClientRectangle.Top + m_borderWidth); Point bottomRight = new Point(this.ClientRectangle.Right - m_curveSize.Width - m_borderWidth, this.ClientRectangle.Bottom - m_curveSize.Height - m_borderWidth); Point bottomLeft = new Point(this.ClientRectangle.Left + m_borderWidth, this.ClientRectangle.Bottom - m_curveSize.Height - m_borderWidth); m_edgePath.AddArc(topLeft.X, topLeft.Y, m_curveSize.Width, m_curveSize.Height, 180, 90); m_edgePath.AddArc(topRight.X, topRight.Y, m_curveSize.Width, m_curveSize.Height, 270, 90); m_edgePath.AddArc(bottomRight.X, bottomRight.Y, m_curveSize.Width, m_curveSize.Height, 0, 90); m_edgePath.AddArc(bottomLeft.X, bottomLeft.Y, m_curveSize.Width, m_curveSize.Height, 90, 90); m_edgePath.CloseFigure(); Region preWidenRegion = new Region(m_edgePath); m_edgePath.Widen(new Pen(Color.Black, m_borderWidth)); Region postWidenRegion = new Region(m_edgePath); m_edgeRegion = new Region(); m_edgeRegion.MakeEmpty(); m_edgeRegion.Union(preWidenRegion); m_edgeRegion.Union(postWidenRegion); Thanks,
4. About get the client rectangle
5. PointToScreen (Client vs screen coordinates) trap for rubber rectangles
keywords: logical coordinates, page coordinates, world coordinates,
device coordinates, physical coordinates, screen coordinates, client
coordinates. offset rectangle. WYSIWYG rubber rectangle problem,
bounded rectangle problem. PointToClient, PointToScreen
Beware this newbie trap for the unwary. It goes by various names (in
some old MFC literature I saw some of the keywords above). Whenever
doing comparisons between points, especially using rubber or bounded
rectangles, you want to convert into screen coordinates (aka logical
coordinates, page coordinates, world coordinates) from client
coordinates (aka device coordinates, physical coordinates).
Below is the pseudocode. If you don't do this, whenever you use a
'rubber rectangle' (also called a bounding rectangle, it's something
you create with a mouse to define an area on your screen), you will be
off by an offset, and you rubber rectangle won't quite be capturing
the area on the screen you think it's at. The offset depends on how
small your client window is relative to the full sized window. So, if
you expand you client window to full size, you'll never have this
problem, but if the user doesn't expand the window, the problem
remains unless you use the solution below. The solution is to employ
PointToScreen method, but it has to be done in the manner shown
below. A quick and dirty workaround to the below, which is nasty IMO,
is simply to require the form be always maximized (I've seen programs
do this, but it's not user friendly IMO).
BTW, as an aside, whenever using a rubber rectangle always "normalize
it" meaning whether the user creates it from left to right or right to
left, it gives the same coordinates, otherwise, if it's not
normalized, you'll only capture the screen when you create the rubber
rectangle a certain way (say dragging left to right). Keyword search
"normalize rectangle". In MFC they used to have a function to do
this, but in C# you have to do it yourself. Also you should search
the web for how to do a rubber rectangle; there's lots of examples.
RL
//pseudocode
public void DoSomethingWithABoundedRectangle (Rectangle boundedRect,
object sender, MouseEventArgs e)
{
Control control = (Control)sender; //required for
PointToScreen!
// Calculate points always using the PointToScreen
method.
foreach (Point Y in MyPointList)
{
Point myfirstPoint = new Point();
myfirstPoint.X = Y.X; myfirstPoint.Y=Y.Y; //etc.etc
myfirstPoint = control.PointToScreen(myfirstPoint); //
prevents offset
if (boundedRect.Contains(myfirstPoint))
{
//Do Something //now the bounded rectangle will not be
offset
}
}
/////////////////// the above function was called by the below event
handler
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
// myRubberR; //create a rubber rectangle, should exist here
DoSomethingWithABoundedRectangle (myRubberR, sender,e);
}
//////////////////////////
6. Reserving an area of client form - CSharp/C#
7. How to get _true_ client area of datagrid
I need to get the actual client area of the datagrid. DataGrid.ClientSize doesn't seem to take into account: borders and scrollbars (if visible). What I need is a way to get the visible width, excluding borders and scrollbars. Any clues?