Re: Bargraphs in VC++ 6.0
You might think that this is simple task, and indeed it is a simple task to
just draw some rectangles.
But the implementation of the plotter depends on your data storage and how
you want it to be presented. So it is fairly difficult for someone to just
give you a simple piece of code to does exactly what you want. (Other than
pointing you to the controls that we have given you links to).
In order to accomplish what you want you will need to know how to make some
GDI calls to draw rectangles using brushes and pens, which I gave you link
for that. Take a look at the documentation for CDC and you should have
everything you need in order to do what you want.
The code that you posted does most of the work, but it had a resource leak,
which can be fixed by calling ReleaseDC at the end. But again the drawing
portion of that code should be in the OnPaint method of the control, and not
in the dialogbox.
I'll try to put an example together.
AliR.
"Kahlua" <kahlua@right.here> wrote in message
news:0Drjj.5944$YW6.1505@trndny07...
Every one of these links you give me are projects full of lots of bell and
whistles which makes it impossible to just find the simple bargraph
portion.
I guess it seems nobody here really knows how to do this task simply.
All I want to do is take a simple string of bytes and translate to a
simple bargraph within a defined area of screen.
I have ways that do work but I am told they are troublesome, yet no one
explains how to do it correctly.
When I do it the only way I know works (which is trouble according to lots
of people) it doesnt re-draw when a window overlaps it.
You keep telling me that I need to do something in the OnPaint() routing
but dont say what.
This is NOT a school project or anything.
It is simply something I am trying to learn to do the right way.
Please someone help me.
"AliR (VC++ MVP)" <AliR@online.nospam> wrote in message
news:Toqjj.33375$4V6.20081@newssvr14.news.prodigy.net...
You can start reading through this set of documents:
http://msdn2.microsoft.com/en-us/library/ms536795(VS.85).aspx
Why aren't you using one of the chart controls posted on code project?
http://www.codeproject.com/KB/miscctrl/CBarChart.aspx
There are tons of them here on CodeGuru:
http://www.codeguru.com/cpp/controls/controls/
AliR.
"Kahlua" <kahlua@right.here> wrote in message
news:Ogpjj.14360$Y63.1295@trnddc03...
Can anyone please explain how to make my bargraph properly using GDI
calls and where to put it?
I want it as simple as possible.
Thanks
There are few flaws in it.
1. The first and most important thing is that the drawing part of this
code
should be in the OnPaint of the child control (IDC_PICT), and not the
dialog. Because if it is not in the OnPaint of the control, then when
the
dialog is covered by another window it will not repaint itself when it
is
uncovered.
2. The fact that it's not scaleable with the data might become a
problem
later, only 10 items......
3. It is not releasing the DC of the child control, which causes a
resource
leak.
4. It is not scalable when it comes to the size of the control.
5. It doesn't have any labels or axes markers.
Otherwise, if you like it feel free to use it.
AliR.
"Kahlua" <kahlua@right.here> wrote in message
news:G%7jj.10188$ac7.2274@trndny03...
"Kahlua" <kahlua@right.here> wrote in message
news:zb6jj.7554$6F6.4662@trndny09...
Can anyone show me how to display a bargraph within my mfc app?
Or direct me to the resource to do it.
Lets say I have an unsigned char string of 16bytes of data ranging in
value from 01h to FFh.
I want to display a bargraph with the 16 vertical bars reflecting the
data value.
Height and width of bargraph not important at this time.
Thanks in advance.
I found this simple code that seems to work ok.
Anything wrong with it?
Why should I not use it?
void CBar1Dlg::OnBar()
{
unsigned char bar[10];
int numbars=10;
int a,b,c,d,i;
for (i=0;i<10;i++) //initialize
bargraph values for testing
bar[i]=i*10;
CRect cr;
CBrush grn(RGB(100,255,100));
c=15,b=5; //initialize
positions
GetDlgItem(IDC_PIC)->GetClientRect(cr); //get drawing area of
PIC
CWnd* pWnd=GetDlgItem(IDC_PIC);
pControlDC=pWnd->GetDC();
d = (cr.Width()-20)/numbars;
pControlDC->SelectObject(wht); //draw
background
pControlDC->Rectangle(0,0,cr.Width(), cr.Height());
pControlDC->SelectObject(grn); //select color
of
bar
for (b=0; b<numkeys; b++)
{
a = bar[b];
pControlDC->Rectangle (c, cr.Height(), c+10, cr.Height()-a);
c+=d;
}
pControlDC->SelectStockObject(BLACK_BRUSH);
}