Missing labels after applying a DefinitionExpression

JeffRogholt

I'm using the WPF ArcGIS Runtime SDK for .Net v100.0.0.0.  The application is consuming an mmpk.  After a DefinitionExpression is applied to a FeatureLayer, the labels of the features are no longer displayed.  How do I get them back?

MaraStoica4

Hi Jeff,

This is an issue we're aware of and it is resolved for our next release early this summer. In the meantime, you could use a GraphicsOverlay as a workaround for your labels

<SPAN class="comment token">// Run query to get all the features in the visible area</SPAN>
<SPAN class="keyword token">var</SPAN> featureLayer <SPAN class="operator token">=</SPAN> mapView<SPAN class="punctuation token">.</SPAN>Map<SPAN class="punctuation token">.</SPAN>OperationalLayers<SPAN class="punctuation token">[</SPAN>layerIndex<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">as</SPAN> FeatureLayer<SPAN class="punctuation token">;</SPAN>

<SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>featureLayer <SPAN class="operator token">!=</SPAN> <SPAN class="keyword token">null</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="punctuation token">{</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> featureTable <SPAN class="operator token">=</SPAN> featureLayer<SPAN class="punctuation token">.</SPAN>FeatureTable<SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">// Set query parameters</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> queryParams <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">QueryParameters</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ReturnGeometry <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">true</SPAN><SPAN class="punctuation token">,</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Geometry <SPAN class="operator token">=</SPAN> mapView<SPAN class="punctuation token">.</SPAN>VisibleArea
&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">// Query the feature table </SPAN>
&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> queryResult <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">await</SPAN> roomsTable<SPAN class="punctuation token">.</SPAN><SPAN class="token function">QueryFeaturesAsync</SPAN><SPAN class="punctuation token">(</SPAN>queryParams<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">// Query using the def query expression</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> labelFeatures <SPAN class="operator token">=</SPAN> queryResult<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Where</SPAN><SPAN class="punctuation token">(</SPAN>f <SPAN class="operator token">=</SPAN><SPAN class="operator token">></SPAN> f<SPAN class="punctuation token">.</SPAN>Attributes<SPAN class="punctuation token">[</SPAN><SPAN class="string token">"DefQueryColumn"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">ToString</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"QueryExpression"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>


&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>labelFeatures <SPAN class="operator token">!=</SPAN> <SPAN class="keyword token">null</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">try</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> graphicsOverlay <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">this</SPAN><SPAN class="punctuation token">.</SPAN>MapView<SPAN class="punctuation token">.</SPAN>GraphicsOverlays<SPAN class="punctuation token">[</SPAN><SPAN class="string token">"LabelsGraphicsOverlay"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; graphicsOverlay<SPAN class="punctuation token">.</SPAN>Graphics<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Clear</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">// Run garbage collector manually to prevent System.ArgumentException </SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; GC<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Collect</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; GC<SPAN class="punctuation token">.</SPAN><SPAN class="token function">WaitForPendingFinalizers</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">foreach</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">var</SPAN> feature <SPAN class="keyword token">in</SPAN> labelFeatures<SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> centerPoint <SPAN class="operator token">=</SPAN> feature<SPAN class="punctuation token">.</SPAN>Geometry<SPAN class="punctuation token">.</SPAN>Extent<SPAN class="punctuation token">.</SPAN><SPAN class="token function">GetCenter</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> label <SPAN class="operator token">=</SPAN> feature<SPAN class="punctuation token">.</SPAN>Attributes<SPAN class="punctuation token">[</SPAN><SPAN class="string token">"LabelAttribute"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>label <SPAN class="operator token">!=</SPAN> <SPAN class="keyword token">null</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">// Create graphic</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> labelText <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">TextSymbol</SPAN><SPAN class="punctuation token">(</SPAN>label<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ToString</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> System<SPAN class="punctuation token">.</SPAN>Drawing<SPAN class="punctuation token">.</SPAN>Color<SPAN class="punctuation token">.</SPAN>Black<SPAN class="punctuation token">,</SPAN> <SPAN class="number token">10</SPAN><SPAN class="punctuation token">,</SPAN> HorizontalAlignment<SPAN class="punctuation token">.</SPAN>Center<SPAN class="punctuation token">,</SPAN> VerticalAlignment<SPAN class="punctuation token">.</SPAN>Middle<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">var</SPAN> labelGraphic <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">Graphic</SPAN><SPAN class="punctuation token">(</SPAN>centerPoint<SPAN class="punctuation token">,</SPAN> labelText<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="comment token">// Add label to map</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; graphicsOverlay<SPAN class="punctuation token">.</SPAN>Graphics<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Add</SPAN><SPAN class="punctuation token">(</SPAN>labelGraphic<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">catch</SPAN> 
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">{</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="punctuation token">}</SPAN>
<SPAN class="punctuation token">}</SPAN>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>