C# modify color of hach in mpolygon

[olivier.eckmann]

Hello,

I try to modifiy colr of hatch pattern's mpolygon.

I can read information in Mpolygon.Hatch.ColorIndex, but if I modify this value, color doesn't change.

If I read again after modification, I obtain the value I've modified, but color doesn't reflect my change.

All other information like angle, scale, hatchpattern can be changed succesfully, but not color.

Do you have any solution?

Thanks

Olivier

[norman.yuan]

I assume that you have set reference to AcMPolygonMgd.dll in your project. To set color of the "Pattern fill color", you do not go down the route MPolygon->Hatch->Color. Instead, simple set MPolygon.PatternColor property to desired color. Following code change a MPolygon's fill color to red:

public static void RunMyMPolyCommand()
        {
            Document dwg = Application.DocumentManager.MdiActiveDocument;
            Editor ed = dwg.Editor;

            PromptEntityOptions opt = new PromptEntityOptions("\nPick a MPloygon entity:");
            opt.SetRejectMessage("Invalid pick: not a MPloygon.");
            opt.AddAllowedClass(typeof(MPolygon), true);
            PromptEntityResult res = ed.GetEntity(opt);

            if (res.Status == PromptStatus.OK)
            {
                ed.WriteMessage("\nPicked entity is {0}", res.ObjectId.ObjectClass.DxfName);

                using (Transaction tran = dwg.Database.TransactionManager.StartTransaction())
                {
                    MPolygon polygon = (MPolygon)tran.GetObject(res.ObjectId, OpenMode.ForWrite);

                    Color color = Color.FromColorIndex(ColorMethod.ByColor, (short)1);
                    polygon.PatternColor = color;

                    tran.Commit();
                }

                ed.WriteMessage("\nMyCmd executed!");
            }
            else
            {
                ed.WriteMessage("\n*Cancel*");
            }
            Autodesk.AutoCAD.Internal.Utils.PostCommandPrompt();
        }

 Hope this is what you are after.

[olivier.eckmann]

Hello,

thanks a lot. until now I used polygon->hatch->patternScale or PatternSpace and all other PatternXXX properties and when I used polygon->hatch->SetHatchPattern all modification was applied (except color)

But now as you've shawn me, I can access these properties directly from mpolygon class and it works fine. And affecting PatternColor works fine too.

But I've a new problem to read the actual patterncolor. In your sample code, I've just added a line after obtaining the mpolygon to read its color :

MPolygon polygon = (MPolygon)tran.GetObject(res.ObjectId, OpenMode.ForWrite);
Color colorused = polygon.PatternColor;

...

and I've a crash "Unhandled acces violation" because PatternColor generated an exception.

So I tried to read the color of Hatch (mpoly->Hatch->Color) but its index is always 257.

I don't know if it can be linked, I don't use MAP3D, but Civil3D 32bit (french version) on Windows7 Pro 32bit (french too).

Do you succeed to read the actual PatternColor without crash?

Thanks 

Olivier

[Anonymous]

Hi Oliver,

We have received reports on 'MPolygon's PatternColor throws an exception' and I could reproduce it in Map 3D / Civil 3D (Civil 3D uses Map 3D module in it). Our QA & development team is current working on a possible fix for this issue, however, I can't comment on when exactly this fix would be available.

Thanks,

[olivier.eckmann]

Hi Partha,

thanks for your information.

Olivier

[Markus_Strauss]

Today i needed this information too - It seems that it is still not fixed in Acad Map 2016

[veli_vaisanen]

Hi,

10 years is quite long time scale to fix .NET wrapper problem. One solution is to use COM API.

Br. Veli

MPolygon mp = (MPolygon)tr.GetObject(o, OpenMode.ForWrite);
if (mp != null)
{
    //-------------------------------------------------------------------------------------
    // Try to mofify entity from COM object. Need to reference AutoCAD MPolygon COM library
    // C:\Program Files\Common Files\Autodesk Shared\AcMPolygon24enu.tlb
    //-------------------------------------------------------------------------------------
    AcMPolygon mpComObj = (AcMPolygon)mp.AcadObject;
    if (mpComObj != null)
    {
        //AXDBLib.AcadAcCmColor mpTrueColor = mpComObj.TrueColor;
        //mpComObj.PatternFillTrueColor = mpTrueColor;
        mpComObj.PatternFillTrueColor = tmpHatchCOMColor;
    }

    //------------------------------------------------------------------------------------------
    // This doesn´t work yet. AutoCAD throw Violation exception if you try to read PatternColor
    //------------------------------------------------------------------------------------------
    //Autodesk.AutoCAD.Colors.Color mpPatternColor = mp.PatternColor;
    //Autodesk.AutoCAD.Colors.ColorMethod mpPatternColorMethod = mp.PatternColor.ColorMethod;
}