topic Re: Is Labelling Graphics Possible in Quartz 100? in .NET Maps SDK Questions

Is Labelling Graphics Possible in Quartz 100?

JamesRichards1 — Tue, 18 Apr 2017 20:37:37 GMT

In 10.2.7 we had ability to label Graphics as explained here:

Label map features—ArcGIS Runtime SDK for .NET | ArcGIS for Developers

Is this functionality missing in Quartz 100? Or am I just not finding it in the documentation?

If this is not available, is it going to be in the next release? We are in the middle of upgrading to Quartz but will have to backslide to 10.2.7 if there is no viable way to label graphics. Labeling them 1 at a time with Text Symbol is not going to work as we need the nice conflict detection that was available in 10.2.7.

Re: Is Labelling Graphics Possible in Quartz 100?

dotMorten_esri — Tue, 18 Apr 2017 21:20:26 GMT

We're hoping to have this available in Update 1.

Re: Is Labelling Graphics Possible in Quartz 100?

JamesRichards1 — Tue, 18 Apr 2017 21:26:08 GMT

Thank you for the quick reply.

Re: Is Labelling Graphics Possible in Quartz 100?

JenniferLink — Tue, 29 Aug 2017 18:09:21 GMT

Is labeling now available at 100.1? And if so, is there a good sample I can follow?

Thanks!

Jen

Re: Is Labelling Graphics Possible in Quartz 100?

dotMorten_esri — Tue, 29 Aug 2017 19:11:22 GMT

Yup:

https://developers.arcgis.com/net/latest/wpf/api-reference//html/P_Esri_ArcGISRuntime_UI_GraphicsOverlay_LabelsEnabled.htm

https://developers.arcgis.com/net/latest/wpf/api-reference//html/P_Esri_ArcGISRuntime_UI_GraphicsOverlay_LabelDefinitions.htm

The full labeling API didn't make it into v100.1, so unfortunately you currently set them using the JSON format from the REST/Webmap specification:

https://developers.arcgis.com/net/latest/wpf/api-reference//html/M_Esri_ArcGISRuntime_Mapping_LabelDefinition_FromJson.htm

Re: Is Labelling Graphics Possible in Quartz 100?

ChuckKnaab — Wed, 13 Nov 2019 00:05:07 GMT

Hi Morten Nielsen,

I'm using the 100.6 runtime and have looked quite a bit at the pages you linked to as well as trying the code sample from the bottom link. Labels work as expected for feature layers, but I'm not able to get labels to show up on graphics. Is there a code sample out there you can point me to on how to accomplish what's listed in the documentation as being supported?

Thanks,

Re: Is Labelling Graphics Possible in Quartz 100?

MichaelBranscomb — Wed, 13 Nov 2019 01:08:09 GMT

Hi,

Yes, labels are supported on GraphicsOverlays - for more information see:

Add labels—ArcGIS Runtime SDK for .NET | ArcGIS for Developers

Show labels on layers | ArcGIS for Developers (the sample is for FeatureLayer but the workflow is the same)

Cheers

Mike

Re: Is Labelling Graphics Possible in Quartz 100?

ChuckKnaab — Sat, 11 Dec 2021 22:38:26 GMT

Thanks for the quick reply Mike. I've been working through issues this morning. I've had a few syntax errors and such that I've been able to work through, but one thing I'm still struggling with now is to create a labeling expression that uses a property that's stored in the Graphic.Attributes dictionary. When labeling FeatureLayers, the $feature global variable is available. Does that variable also apply to a graphic object? The documenation here: Profiles | ArcGIS for Developers says the type for that variable is a "Feature" (Type System | ArcGIS for Developers ) and I wasn't sure if a graphic is also included in that or not. I've tried things like:

""labelExpressionInfo"": {
 ""expression"": ""return $feature.Attributes[\""MyFieldKey\""] + \"" (arcade)\"";""
 }‍‍‍‍‍‍

However, I either run into parsing errors or nothing shows up on the map. Ideally, I'd check to see if the key exists in the dictionary, then return the value in that case, but have also not had luck with conditional statements in the labeling expression. Is there something I'm missing?

Re: Is Labelling Graphics Possible in Quartz 100?

ChuckKnaab — Mon, 18 Nov 2019 16:15:33 GMT

Hi Michael Branscomb‌,

Have you had a chance to review my comment above? Do you have any recommendations?

Re: Is Labelling Graphics Possible in Quartz 100?

MichaelBranscomb — Mon, 18 Nov 2019 21:14:52 GMT

Chuck,

Labeling by the attribute should work via: "$feature.Name" or "$feature["name"]".

If you want to append strings, then you can use something like this "$feature.name + ' Street'".

And finally functions/evaluations should work e.g. "if ($feature.id > 20) $feature.name + ' St'; else $feature.LongName + ' ' + $feature.ending".

Regards

Mike

Re: Is Labelling Graphics Possible in Quartz 100?

ChuckKnaab — Sat, 11 Dec 2021 22:38:29 GMT

Hi Micheal,

Thanks for the help. That was exactly what I needed! I wasn't expecting to be able to eliminate the "Attributes" property name from the $feature object when accessing data stored in that dictionary. I think that would be a worthy addition to the documentation for sure.

Here is a full code sample for anyone else that might come across this in the future:

using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using System.Drawing;
using System.Windows;
using System.Threading.Tasks;
using Esri.ArcGISRuntime.Geometry;

namespace EsriGraphicsLabelExample
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private const string LabelDefinitionJson =
            @"{
                    ""labelExpressionInfo"":{""expression"":""$feature.MyCustomKey""},
                    ""labelPlacement"":""esriServerPointLabelPlacementAboveLeft"",
                    ""symbol"":
                        { 
                            ""angle"":0,
                            ""backgroundColor"":[0,0,0,0],
                            ""borderLineColor"":[0,0,0,0],
                            ""borderLineSize"":0,
                            ""color"":[0,0,255,255],
                            ""font"":
                                {
                                    ""decoration"":""none"",
                                    ""size"":10,
                                    ""style"":""normal"",
                                    ""weight"":""normal""
                                },
                            ""haloColor"":[255,255,255,255],
                            ""haloSize"":2,
                            ""horizontalAlignment"":""center"",
                            ""kerning"":false,
                            ""type"":""esriTS"",
                            ""verticalAlignment"":""middle"",
                            ""xoffset"":0,
                            ""yoffset"":0
                        }
               }";

        public MainWindow()
        {
            InitializeComponent();
            Initialize();
        }

        private async Task Initialize()
        {
            // Create the map with streets basemap.
            MyMapView.Map = new Map(Basemap.CreateStreets());
  
            //Create a new graphic.
            var graphic1 = new Graphic(new MapPoint(0, 0, MyMapView.SpatialReference), new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Cross, Color.Red, size:10));
            graphic1.Attributes["MyCustomKey"] = null;

            //Load the label definition from Json.
            var labelDefinition = LabelDefinition.FromJson(LabelDefinitionJson);

            var overlay = new GraphicsOverlay()
            {
                Id = "MyOverlay",
                LabelsEnabled = true,
                LabelDefinitions = { labelDefinition }
            };

            var graphic2 = new Graphic(new MapPoint(100, 100, MyMapView.SpatialReference), new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Triangle, Color.Blue, size: 10));
            //Set a property in the graphic's Attributes dictionary to symbolize off of: 
            graphic2.Attributes["MyCustomKey"] = 123;

            //Add the graphics to the overlay.
            overlay.Graphics.Add(graphic1);
            overlay.Graphics.Add(graphic2);

            // Add the graphics overlay to the map view
            MyMapView.GraphicsOverlays.Add(overlay);

            MyMapView.Map.InitialViewpoint = new Viewpoint(0, 0, 1000);
        }
    }
}
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

And simple window xaml for testing:

<Window x:Class="EsriGraphicsLabelExample.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:esri="http://schemas.esri.com/arcgis/runtime/2013"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <esri:MapView x:Name="MyMapView" />
    </Grid>
</Window>‍‍‍‍‍‍‍‍‍‍‍‍

Thanks!