A label next to one single point

Lars Iversen · Post by **Lars Iversen** » Mon Mar 06, 2006 3:23 pm

Hi I have a graph with a lot of point on a linegraph

Is it possible to add some text next to one of the points in the graph?
How?

Thanks in advance

Lars Iversen

Narcís · Post by **Narcís** » Mon Mar 06, 2006 3:54 pm

Hi Lars,

Yes, you have several options here:

1. Custom drawing on TeeChart's canvas in the AfterDraw event:

Code: Select all

		private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g)
		{
			g.TextOut(line1.CalcXPos(5),line1.CalcYPos(5),"My Custom Text");
		}

This code draws the text at the 5th point in the series.

2. Using an Annotation tool. For examples have a look at All Features\Welcome !\Tools\Annotation example in TeeChart's features demo which can be found at its program group.

3. Make series marks visible and use the series GetMarkText event:

Code: Select all

		private void line1_GetSeriesMark(Steema.TeeChart.Styles.Series series, Steema.TeeChart.Styles.GetSeriesMarkEventArgs e)
		{
			if (e.ValueIndex!=5) e.MarkText="";
			else e.MarkText="My Custom Text";
		}

Lars Iversen · Post by **Lars Iversen** » Tue Mar 07, 2006 9:25 am

Hi Narcis

Thanks for your quick reply. option 1 with TextOut looks like the one I'm looking for. One problem though:
I would like the text to be rotated 90 degrees so that it starts from the bottom.

Can that be done?

Thanks in advance
Lars Iversen

Narcís · Post by **Narcís** » Tue Mar 07, 2006 9:37 am

Hi Lars,

Ok, then instead of TextOut you should use RotateLabel which also lets you specifing the rotation angle you want for the label.

Lars Iversen · Post by **Lars Iversen** » Tue Mar 07, 2006 9:43 am

You guys are cool !!
Thanks

...and just one more thing (I think):

Is it also possible to control font size, color etc. ?

Br Lars Iversen

Narcís · Post by **Narcís** » Tue Mar 07, 2006 10:05 am

You're very welcome Lars

.

Yes, this is also possible. You need to use:

Code: Select all

		private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g)
		{
			g.Font.Color = Color.Blue;
			g.Font.Size=14;
			g.Font.Name="Times New Roman";
			g.RotateLabel(100,100,"Rotated Label", 45);
		}

Lars Iversen · Post by **Lars Iversen** » Tue Mar 07, 2006 10:11 am

Perfect !

Thanks for great en fast support.

Teechart rules !

/Lars

Lars Iversen · Post by **Lars Iversen** » Tue Mar 07, 2006 10:50 am

OK. Now I got it to work with this point label, but now if I zoom my graph the series are disappering !?!?
If I undo zoom, my series appear again!?
(During zomm I update some series as they are a dynamic average that averages the poins that are visible. I don't know if that interfers with the functionality)

If you have an email address I can try to create a small isolated example of the problem.

Br
Lars Iversen

Narcís · Post by **Narcís** » Tue Mar 07, 2006 10:54 am

Hi Lars,

Yes please, could you post an example we can run "as-is" to reproduce the problem here?

You can post your files at news://www.steema.net/steema.public.attachments newsgroup.

Lars Iversen · Post by **Lars Iversen** » Tue Mar 07, 2006 12:24 pm

Hi Thanks again

While trying to create the example I found out what the problem was:

When I have created my series
I set the left axis to autoscale
I Refresh the graph
then I store the MaxY and MinY values in two variables
Heres some of my code:

call CreateSeries()

TChart1.Axes.Left.Automatic = True
TChart1.Refresh()

m_dblYMax = TChart1.Axes.Left.Maximum
m_dblYMin = TChart1.Axes.Left.Minimum

I use the two variables m_dblYMax and Min in this way:
When the user zooms or scrolls i set the left axis minimum and maximum to the saved values. this way the user can only zoom the x-axis (That is what I want in this case)

This works fine when I have no code in the AfterDraw Event.
If I add this code in after draw:

For _i As Integer = 0 To TChart1.Series(0).Count - 1
If TChart1.Series(0).Item(_i).Label <> "" Then
g.RotateLabel(TChart1.Series(0).CalcXPos(_i), TChart1.Series(0).CalcYPos(_i), TChart1.Series(0).Item(_i).Label, 90)
End If

Next _i

Then My two variables ( m_dblYMax and m_dblYMin) are always zero. So in my zoom event i accidentially set min and max on the left axis to zero.

Is there a way to make it work so I can use:
m_dblYMax = TChart1.Axes.Left.Maximum
m_dblYMin = TChart1.Axes.Left.Minimum

Thanks

Lars Iversen

Narcís · Post by **Narcís** » Tue Mar 07, 2006 1:01 pm

Hi Lars,

When the user zooms or scrolls i set the left axis minimum and maximum to the saved values. this way the user can only zoom the x-axis (That is what I want in this case)

Have you tried setting the zoom direction?

Code: Select all

tChart1.Zoom.Direction=Steema.TeeChart.ZoomDirections.Horizontal;

Then My two variables ( m_dblYMax and m_dblYMin) are always zero. So in my zoom event i accidentially set min and max on the left axis to zero.

Is there a way to make it work so I can use:
m_dblYMax = TChart1.Axes.Left.Maximum
m_dblYMin = TChart1.Axes.Left.Minimum

You need to make that assignment in a place where the axes are already drawn so that they have valid values. You may want to try using the line below before executing those statements.

Code: Select all

Bitmap bmp=tChart1.Bitmap;

Lars Iversen · Post by **Lars Iversen** » Tue Mar 07, 2006 1:44 pm

Yes sir that thing about setting horizontal zoom only helps a lot and now I set the max and min from trhe series(0).MaxYValue and series(0).MinYValue.
That seems to work perfectly.

Thanks again

Lars Iversen