Topic: VB.NET to C#

[jsr]

Hi all

while going through Fenton Web's .NET API video tutorial, He searched for left mouse clicks using following code in an event handler routine .

if(args.Context.History AND PointHistoryBits.NotDigitizer)

I am coding in C# and dont know how to translate above to C# statement. Please guide.

Thanks

[Jeff H]

In VB the And is a logical and bitwise operator

[Kerry]

(args.Context.History && PointHistoryBits.NotDigitizer);

[jsr]

Thanks for the replies,

but I have tried that syntax and getting following error message. Please guide.



            // Check to see if mouse has been Clicked.
            if(args.Context.History && PointHistoryBits.NotDigitizer)
            {
                // Create a Circle
                Circle c = new Circle(args.Context.RawPoint, Vector3d.ZAxis, 10);

                args.Context.DrawContext.Geometry.Draw(c);
                System.Threading.Thread.Sleep(50);
                // Set the new Radius.
                c.Radius = 20;
                args.Context.DrawContext.Geometry.Draw(c);
                System.Threading.Thread.Sleep(50);
                // Set the new Radius.
                c.Radius = 40;
                args.Context.DrawContext.Geometry.Draw(c);
            }


Operator '&&' cannot be applied to operands of type 'Autodesk.AutoCAD.EditorInput.PointHistoryBits' and 'Autodesk.AutoCAD.EditorInput.PointHistoryBits'.

[gile]

Hi,

So, it's a bitwise AND operator: '&' in C#.

Code: [Select]

if (args.Context.History & PointHistoryBits.NotDigitizer == 2) ...

[sinc]

You would not want to use the "== 2" part...   That wouldn't work right.

[gile]

You would not want to use the "== 2" part...   That wouldn't work right.

Oopss !

Some casts and parents missing...

Maybe:

Code: [Select]

if (((int)args.Context.History & (int)PointHistoryBits.NotDigitizer) == 2) ...
or (more concise)

Code: [Select]

if (((int)args.Context.History & 2) == 2) ...

[sinc]

Actually, the "== 2" would work right, it's just that the whole point of having an enumeration like PointHistoryBits is so that you don't hard-code enumeration values in your code.  (Well, that, and the fact that the enumeration helps "comment" the code.)

So you should use something like this:

Code: [Select]

if ((e.Context.History & PointHistoryBits.NotDigitizer) == PointHistoryBits.NotDigitizer)
Or, a bit simpler:

Code: [Select]

if ((e.Context.History & PointHistoryBits.NotDigitizer) > 0)

[It's Alive!]

would this work as well?

Code: [Select]

if ((e.Context.History & PointHistoryBits.NotDigitizer) != 0)


[Kerry]

jsr
do you have the link to the original source ??

[pkohut]

would this work as well?

Code: [Select]

if ((e.Context.History & PointHistoryBits.NotDigitizer) != 0)


Semantic sugar. Sinc's version is clearer to the casual observer by not introducing a negative context into the statement.

[jsr]

Thanks everybody for the interest in my post.

Kerry, I saw this code in AutoCAD .NET  api tutorial from Fenton Web. It was in VB.NET and what he wrote was

 if(args.Context.History AND PointHistoryBits.NotDigitizer)

Now as per the suggestions given yesterday, if I use

 if(args.Context.History & PointHistoryBits.NotDigitizer == 2)

compiler says that we cannot compare int with PointHistoryBits.NotDigitizer, so even this version is not working.

Thanks again.

[Kerry]

did it look something like this ?

Code: [Select]

// ok, so now lets do something really pointless! space invaders!
if ((e.Context.History & PointHistoryBits.NotDigitizer) > PointHistoryBits.DidNotPick)
{
// this means the mouse has been clicked... so...
// create a Circle
Circle circle = new Circle(e.Context.RawPoint, Vector3d.ZAxis, 10);
// draw it
e.Context.DrawContext.Geometry.Draw(circle);
// wait for a while
System.Threading.Thread.Sleep(50);
// draw
circle.Radius = 20;
e.Context.DrawContext.Geometry.Draw(circle);
// wait for a while
System.Threading.Thread.Sleep(50);
// draw it
circle.Radius = 40;
e.Context.DrawContext.Geometry.Draw(circle);
// wait for a while
System.Threading.Thread.Sleep(50);
// draw it
circle.Radius = 80;
e.Context.DrawContext.Geometry.Draw(circle);
// wait for a while
System.Threading.Thread.Sleep(50);
}
ie:
was it related to this http://www.theswamp.org/index.php?topic=19780.0

Was the original something like this ?

Code: [Select]

    ' ok, so now lets do something really pointless! space invaders!
    If (e.Context.History And PointHistoryBits.NotDigitizer) Then
      ' this means the mouse has been clicked... so...
      ' create a Circle
      Dim circle As Circle = New Circle(e.Context.RawPoint, Vector3d.ZAxis, 10)
      ' draw it
      e.Context.DrawContext.Geometry.Draw(circle)
      ' wait for a while
      System.Threading.Thread.Sleep(50)
      ' draw it
      circle.Radius = 20
      e.Context.DrawContext.Geometry.Draw(circle)
      ' wait for a while
      System.Threading.Thread.Sleep(50)
      ' draw it
      circle.Radius = 40
      e.Context.DrawContext.Geometry.Draw(circle)
      ' wait for a while
      System.Threading.Thread.Sleep(50)
      ' draw it
      circle.Radius = 80
      e.Context.DrawContext.Geometry.Draw(circle)
      ' wait for a while
      System.Threading.Thread.Sleep(50)

    End If




[gile]

OK, the (corrected) solutions I posted are verbose and not very elegant.
I learned about Enum using...

Another thing about the code contained in the 'then' statement: IMO the created circle (which isn't added to the database) have to be explicitly disposed.

Use this:

Code: [Select]

if ((e.Context.History & PointHistoryBits.NotDigitizer) == PointHistoryBits.NotDigitizer)
            {
                // this means the mouse has been clicked... so...
                // create a Circle
                using (Circle circle = new Circle(e.Context.RawPoint, Vector3d.ZAxis, 10))
                {
                    // draw it
                    e.Context.DrawContext.Geometry.Draw(circle);
                    // wait for a while
                    System.Threading.Thread.Sleep(50);
                    // draw
                    circle.Radius = 20;
                    e.Context.DrawContext.Geometry.Draw(circle);
                    // wait for a while
                    System.Threading.Thread.Sleep(50);
                    // draw it
                    circle.Radius = 40;
                    e.Context.DrawContext.Geometry.Draw(circle);
                    // wait for a while
                    System.Threading.Thread.Sleep(50);
                    // draw it
                    circle.Radius = 80;
                    e.Context.DrawContext.Geometry.Draw(circle);
                    // wait for a while
                    System.Threading.Thread.Sleep(50);
                } // Dispose the Circle
            }
To avoid this:

[It's Alive!]

would this work as well?

Code: [Select]

if ((e.Context.History & PointHistoryBits.NotDigitizer) != 0)


Semantic sugar. Sinc's version is clearer to the casual observer by not introducing a negative context into the statement.

in that case, how about

Code: [Select]

if(Convert.ToBoolean(e.Context.History & PointHistoryBits.NotDigitizer))