Graphics.MeasureString

26 Oct 2006 12:23 PM

Anil Gupte

I copied the following almost directly from
http://msdn2.microsoft.com/en-us/library/6xe5hazb.aspx

Dim instance As Graphics

Dim text As String

'Dim strfont As Font

Dim returnValue As SizeF

text = "asdas asd asd asd"

Dim strfont As New Font("Arial", 16)

returnValue = instance.MeasureString(text, strfont)

and it still does not work! I get an error saying Oject reference is not
set to an intance of an object. I have tried all kinds of combinations, but
it still will not work. In the documentation i.e. dynamic help the
implementation seems to be different.

Can anyone tell me how to implement this?

Thanx,

--
Anil Gupte
www.keeninc.net
www.icinema.com

26 Oct 2006 12:36 PM

Truong Hong Thi

Hi Anil,

The variable "instance" is declared but not assigned, and you get an
NullReferenceException.
If you are inside a Paint event handler, set e.Graphics to it.

Otherwise, you could use Control.CreateGraphics.

Using instance As Graphics = someControl.CreateGraphics()
' code here
End Using

Thi
http://thith.blogspot.com/

Anil Gupte wrote:
Show quoteHide quote

> I copied the following almost directly from
> http://msdn2.microsoft.com/en-us/library/6xe5hazb.aspx
>
> Dim instance As Graphics
>
> Dim text As String
>
> 'Dim strfont As Font
>
> Dim returnValue As SizeF
>
> text = "asdas asd asd asd"
>
> Dim strfont As New Font("Arial", 16)
>
> returnValue = instance.MeasureString(text, strfont)
>
>
> and it still does not work! I get an error saying Oject reference is not
> set to an intance of an object. I have tried all kinds of combinations, but
> it still will not work. In the documentation i.e. dynamic help the
> implementation seems to be different.
>
> Can anyone tell me how to implement this?
>
> Thanx,
> --
> Anil Gupte
> www.keeninc.net
> www.icinema.com

26 Oct 2006 12:43 PM

Norman Chong

Truong Hong Thi schrieb:

Seems I was a few minutes too late... :-)

26 Oct 2006 4:34 PM

Anil Gupte

Yes, only 4 minutes. :-) But thanx to both of you. I now understand how to
do it but seems exceptionally convoluted. I had inf act tried the New
keyword and it still had not worked. A class that you can't really use? How
like Microsoft....

Anyway thanx again to both.

--
Anil Gupte
www.keeninc.net
www.icinema.com

Show quoteHide quote

"Norman Chong" <normanch***@freenet.de> wrote in message
news:1161866581.647399.84180@e3g2000cwe.googlegroups.com...
>
> Truong Hong Thi schrieb:
>
> Seems I was a few minutes too late... :-)
>

26 Oct 2006 12:40 PM

Norman Chong

Anil Gupte schrieb:

>
> and it still does not work! I get an error saying Oject reference is not
> set to an intance of an object. I have tried all kinds of combinations, but
> it still will not work. In the documentation i.e. dynamic help the
> implementation seems to be different.

Hi Anil,

The error is correct :-)
When you just write "Dim instance As Graphics" you don't have an
instance of this class. When you debug it you see that the value of
'instance' is nothing. Normally it must be "Dim instance as new
Graphics" but because Graphics has no constructors, this won't work
too.
So you have to get the graphics object from another object which can
create a graphics object for you (e.g. a Control)

Example ( Get Graphics object from a textbox) :
Dim myGraphics as Graphics
myGraphics = TextBox1.createGraphics()