Area Feature Name/Description Modification

nickgoodliff

I need to alter the name and description for some area features based on some attribute, so that my export to KML will display correctly.

I have tried the following:

                    IntPtr theLayerHandlePtr = (IntPtr)(theLayerList.ToInt64() + i * IntPtr.Size);

                    IntPtr theLayerHandle = Marshal.PtrToStructure<IntPtr>(theLayerHandlePtr);

                    // Add the layer

                    // Get the layer info and copy it into our structure

                    GlobalMapperDLLWrapper.GM_LayerInfo_t theLayerInfo = new GlobalMapperDLLWrapper.GM_LayerInfo_t();

                    IntPtr theInfoPtr = GlobalMapperDLL.GM_GetLayerInfo(theLayerHandle);

                    theLayerInfo = Marshal.PtrToStructure<GM_LayerInfo_t>(theInfoPtr);

                        for (uint x = 0; x < theLayerInfo.mNumAreas; x++)

                        {

                            GM_AreaFeature_t areaFeature = new GM_AreaFeature_t();

                            IntPtr areaFeaturePtr = GlobalMapperDLL.GM_GetAreaFeature(theLayerHandle, x);

                            areaFeature = Marshal.PtrToStructure<GM_AreaFeature_t>(areaFeaturePtr);

                            var attrs = areaFeature.mFeatureInfo.getAttrValueList();

                            areaFeature.mFeatureInfo.mDesc = "";

                            foreach (var attr in attrs)

                            {

                                if (attr.mName == "NTM_ID")

                                    areaFeature.mFeatureInfo.mName = attr.mVal;

                                areaFeature.mFeatureInfo.mDesc += attr.mName + ": " + attr.mVal + "<br />";

                            }

                            Marshal.StructureToPtr<GM_AreaFeature_t>(areaFeature, areaFeaturePtr, true);

                        }

                    

But my changes never seem to be saved, and I end up with a load of area features with "Unknown Area Type" as the description and no name.

Cheers
Nick

bmg_bob

I took a quick look at your code, and I didn't see anything that was obviously wrong.  I recommend that you send an e-mail describing your problem to Blue Marble Geographics Support (geohelp@bluemarblegeo.com).  This will ensure that the Developer Support team sees the problem and can provide you with a timely response.  Thank you.

aaronc

Hey I was working on some things with the SDK and thought about this question, If you haven't had it answered yet.  If you want your layer description changes to be saved you should be using the function:

        /// <summary>

        /// Sets the description for the layer

        /// </summary>

        /// <param name="aLayer">Layer to set description for</param>

        /// <param name="aDesc">Description to use (pass NULL to restore default)</param>

        /// <returns></returns>

        [DllImport(DLLFileName, EntryPoint = "GM_SetLayerDescription")]

        public static extern GM_Error_t32 GM_SetLayerDescription

            (

            GM_LayerHandle_t32  aLayer,         // layer to set description for

            String              aDesc           // description to use (pass NULL to restore default)

            );

If that function does not exist in the global mapper wrapper then add the above under the GlobalMapperDLL class in that file.

Hopefully that helps

nickgoodliff

Thanks Aaron, but this is not quite what I am after. I need to set the name and description of each Area Feature in a layer, not the whole layer itself.

If there is anything you can do help on this that would be great.

Nick

aaronc

oops, I read part of the code wrong.  I haven't played with this function yet but it might be what you are looking for:      
        /// <summary>

        /// Sets the list of attribute/values to use for the specified feature.

        /// </summary>

        /// <param name="aLayer">IN: Layer the feature is in</param>

        /// <param name="aFeatureClassType">IN: Type of feature class (area, point, line)</param>

        /// <param name="aFeatureIndex">IN: Index of feature in layer</param>

        /// <param name="aAttrList">IN: New list of attributes to associate with feature</param>

        /// <param name="aNumAttrs">IN: Number of attributes in aAttrList</param>

        [DllImport(DLLFileName, EntryPoint = "GM_SetFeatureAttrList")]

        public static extern GM_Error_t32 GM_SetFeatureAttrList

            (

            GM_LayerHandle_t32      aLayer,             // IN: Layer the feature is in

            GM_FeatureClassType_t8  aFeatureClassType,  // IN: Type of feature class (area, point, line)

            UInt32                  aFeatureIndex,      // IN: Index of feature in layer

            IntPtr                    aAttrList,          // (GM_AttrValue_t)IN: New list of attributes to associate with feature

            UInt16                  aNumAttrs           // IN: Number of attributes in aAttrList

            );

Again I haven't done anything with this function but if you add it to the wrapper in the same place I mentioned the other this should be what you are looking for.

nickgoodliff

Hi Aaron,

I checkout the GlobalMapperInterface.h file and found a couple more functions that I have added to my c# wrapper:

// Sets the description to use for the feature.

GM_DLL_EXPORTED GM_Error_t32 __stdcall GM_SetFeatureDescription

    (

    GM_LayerHandle_t32      aLayer,             // IN: Layer the feature is in

    GM_FeatureClassType_t8  aFeatureClassType,  // IN: Type of feature class (area, point, line)

    uint32                  aFeatureIndex,      // IN: Index of feature in layer

    const char*             aDesc               // IN: New description for feature (NULL to reset to default)

    );

// Sets the display label to use for the feature.

GM_DLL_EXPORTED GM_Error_t32 __stdcall GM_SetFeatureLabel

    (

    GM_LayerHandle_t32      aLayer,             // IN: Layer the feature is in

    GM_FeatureClassType_t8  aFeatureClassType,  // IN: Type of feature class (area, point, line)

    uint32                  aFeatureIndex,      // IN: Index of feature in layer

    const 

The top one works perfectly and allows me to add info that is used for the KMZ export. The bottom one, SetFeatureLabel doesn't seem to do anything.

It would be great if there was a function for GM_SetFeatureName as that is all that I am missing!

Cheers
Nick