How to render color of individual features based on field in another table

Douglas_DMeredith

Say I have a geodatabase containing a feature class with the following fields:

objectid    mapunit    geom

The mapunits are defined in another table that includes a color:

objectid    mapunit(unique)    color

How can I render the features in the feature class in the color corresponding to their mapunit?

I've experimented with unique value renderers, but I can't figure out how to use them to assign a specific color to a specific value of mapunit.

It seems like this was possible in an older .NET SDK ("Unique value renderer section" in https://developers.arcgis.com/net/10-2/desktop/guide/symbols-and-renderers.htm). But with ArcGIS Pro, you have to specify a color ramp and one or more fields to examine. I don't see a way to map to specific values of those fields.

If I specify a color ramp from the colors in the definition table, it seems like the renderer uses a first-come assignment to the values it finds in the mapunit field of the feature class--I don't have control over that mapping.

Does anyone have any suggestions?

Wolf

I attached the sample code to create a Unique Value Renderer.  I also attached a sample Pro project that works in conjunction with the sample code.  The key code snippet is the creation of the unique value renderer:

<SPAN class="comment token">/// <summary></SPAN>
<SPAN class="comment token">/// You must call this method on the MCT!</SPAN>
<SPAN class="comment token">/// </summary></SPAN>
<SPAN class="comment token">/// <returns></returns></SPAN>
<SPAN class="keyword token">private</SPAN> CIMRenderer <SPAN class="token function">CreateUniqueValueRendererUsingColorTable</SPAN><SPAN class="punctuation token">(</SPAN>FeatureLayer lyrToColor<SPAN class="punctuation token">,</SPAN> 
  StandaloneTable colorTable<SPAN class="punctuation token">)</SPAN>
<SPAN class="punctuation token">{</SPAN>
  <SPAN class="comment token">//All of these methods have to be called on the MCT</SPAN>
  <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>OnUIThread<SPAN class="punctuation token">)</SPAN>
    <SPAN class="keyword token">throw</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">ArcGIS<SPAN class="punctuation token">.</SPAN>Core<SPAN class="punctuation token">.</SPAN>CalledOnWrongThreadException</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

  <SPAN class="comment token">//make a dictionary with MapUnit and Color</SPAN>
  <SPAN class="keyword token">var</SPAN> dicMapUnitColor <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">Dictionary</SPAN><SPAN class="operator token"><</SPAN><SPAN class="keyword token">int</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="keyword token">string</SPAN><SPAN class="operator token">></SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
  <SPAN class="keyword token">using</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">var</SPAN> rowCursor <SPAN class="operator token">=</SPAN> colorTable<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Search</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>
  <SPAN class="punctuation token">{</SPAN>
    <SPAN class="keyword token">while</SPAN> <SPAN class="punctuation token">(</SPAN>rowCursor<SPAN class="punctuation token">.</SPAN><SPAN class="token function">MoveNext</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>
    <SPAN class="punctuation token">{</SPAN>
      <SPAN class="keyword token">using</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">var</SPAN> anyRow <SPAN class="operator token">=</SPAN> rowCursor<SPAN class="punctuation token">.</SPAN>Current<SPAN class="punctuation token">)</SPAN>
      <SPAN class="punctuation token">{</SPAN>
        dicMapUnitColor<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Add</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">int</SPAN><SPAN class="punctuation token">)</SPAN>anyRow<SPAN class="punctuation token">[</SPAN><SPAN class="string token">"MapUnit"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> anyRow<SPAN class="punctuation token">[</SPAN><SPAN class="string token">"Color"</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="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
      <SPAN class="punctuation token">}</SPAN>
    <SPAN class="punctuation token">}</SPAN>
  <SPAN class="punctuation token">}</SPAN>

  <SPAN class="comment token">//Create the Unique Value Renderer</SPAN>
  CIMUniqueValueRenderer uniqueValueRenderer <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">CIMUniqueValueRenderer</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
  <SPAN class="punctuation token">{</SPAN>
    <SPAN class="comment token">// set the value field</SPAN>
    Fields <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">string</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">{</SPAN> <SPAN class="string token">"MapUnit"</SPAN> <SPAN class="punctuation token">}</SPAN>
  <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>

  <SPAN class="comment token">//Construct the list of UniqueValueClasses</SPAN>
  List<SPAN class="operator token"><</SPAN>CIMUniqueValueClass<SPAN class="operator token">></SPAN> classes <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">List</SPAN><SPAN class="operator token"><</SPAN>CIMUniqueValueClass<SPAN class="operator token">></SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

  <SPAN class="comment token">//define the unique values for each dicMapUnitColor entry</SPAN>
  <SPAN class="keyword token">foreach</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">var</SPAN> key <SPAN class="keyword token">in</SPAN> dicMapUnitColor<SPAN class="punctuation token">.</SPAN>Keys<SPAN class="punctuation token">)</SPAN>
  <SPAN class="punctuation token">{</SPAN>
    <SPAN class="keyword token">var</SPAN> lstValue <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">List</SPAN><SPAN class="operator token"><</SPAN>CIMUniqueValue<SPAN class="operator token">></SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
    <SPAN class="punctuation token">{</SPAN>
      <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">CIMUniqueValue</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
        <SPAN class="punctuation token">{</SPAN>
          FieldValues <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">string</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">{</SPAN> key<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>
        <SPAN class="punctuation token">}</SPAN>
    <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>
    <SPAN class="keyword token">var</SPAN> namedColor <SPAN class="operator token">=</SPAN> System<SPAN class="punctuation token">.</SPAN>Drawing<SPAN class="punctuation token">.</SPAN>Color<SPAN class="punctuation token">.</SPAN><SPAN class="token function">FromName</SPAN><SPAN class="punctuation token">(</SPAN>dicMapUnitColor<SPAN class="punctuation token">[</SPAN>key<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
    <SPAN class="keyword token">var</SPAN> theColor <SPAN class="operator token">=</SPAN> CIMColor<SPAN class="punctuation token">.</SPAN><SPAN class="token function">CreateRGBColor</SPAN><SPAN class="punctuation token">(</SPAN>namedColor<SPAN class="punctuation token">.</SPAN>R<SPAN class="punctuation token">,</SPAN> namedColor<SPAN class="punctuation token">.</SPAN>G<SPAN class="punctuation token">,</SPAN> namedColor<SPAN class="punctuation token">.</SPAN>B<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
    classes<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Add</SPAN><SPAN class="punctuation token">(</SPAN>
      <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">CIMUniqueValueClass</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
        <SPAN class="punctuation token">{</SPAN>
          Values <SPAN class="operator token">=</SPAN> lstValue<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ToArray</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN>
          Label <SPAN class="operator token">=</SPAN> $<SPAN class="string token">@"Color: {dicMapUnitColor[key]}"</SPAN><SPAN class="punctuation token">,</SPAN>
          Visible <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">true</SPAN><SPAN class="punctuation token">,</SPAN>
          Editable <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">true</SPAN><SPAN class="punctuation token">,</SPAN>
          Symbol <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">CIMSymbolReference</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">{</SPAN> 
            Symbol <SPAN class="operator token">=</SPAN> SymbolFactory<SPAN class="punctuation token">.</SPAN>Instance<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ConstructPointSymbol</SPAN><SPAN class="punctuation token">(</SPAN>
              SymbolFactory<SPAN class="punctuation token">.</SPAN>Instance<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ConstructMarker</SPAN><SPAN class="punctuation token">(</SPAN>theColor<SPAN class="punctuation token">,</SPAN> <SPAN class="number token">20</SPAN><SPAN class="punctuation token">,</SPAN> SimpleMarkerStyle<SPAN class="punctuation token">.</SPAN>Pushpin<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">}</SPAN>
        <SPAN class="punctuation token">}</SPAN>
      <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
  <SPAN class="punctuation token">}</SPAN>

  <SPAN class="comment token">//Add the classes to a group (by default there is only one group or "symbol level")</SPAN>
  <SPAN class="comment token">// Unique value groups</SPAN>
  CIMUniqueValueGroup groupOne <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">CIMUniqueValueGroup</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
  <SPAN class="punctuation token">{</SPAN>
    Heading <SPAN class="operator token">=</SPAN> <SPAN class="string token">"By Color"</SPAN><SPAN class="punctuation token">,</SPAN>
    Classes <SPAN class="operator token">=</SPAN> classes<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ToArray</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
  <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>
  uniqueValueRenderer<SPAN class="punctuation token">.</SPAN>Groups <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">CIMUniqueValueGroup</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">{</SPAN> groupOne <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>

  <SPAN class="comment token">//Draw the rest with the default symbol</SPAN>
  uniqueValueRenderer<SPAN class="punctuation token">.</SPAN>UseDefaultSymbol <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">true</SPAN><SPAN class="punctuation token">;</SPAN>
  uniqueValueRenderer<SPAN class="punctuation token">.</SPAN>DefaultLabel <SPAN class="operator token">=</SPAN> <SPAN class="string token">"All other values"</SPAN><SPAN class="punctuation token">;</SPAN>

  <SPAN class="keyword token">var</SPAN> defaultColor <SPAN class="operator token">=</SPAN> CIMColor<SPAN class="punctuation token">.</SPAN><SPAN class="token function">CreateRGBColor</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">215</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">215</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">215</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
  uniqueValueRenderer<SPAN class="punctuation token">.</SPAN>DefaultSymbol <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">CIMSymbolReference</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
  <SPAN class="punctuation token">{</SPAN>
    Symbol <SPAN class="operator token">=</SPAN> SymbolFactory<SPAN class="punctuation token">.</SPAN>Instance<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ConstructPointSymbol</SPAN><SPAN class="punctuation token">(</SPAN>
              SymbolFactory<SPAN class="punctuation token">.</SPAN>Instance<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ConstructMarker</SPAN><SPAN class="punctuation token">(</SPAN>defaultColor<SPAN class="punctuation token">,</SPAN> <SPAN class="number token">15</SPAN><SPAN class="punctuation token">,</SPAN> SimpleMarkerStyle<SPAN class="punctuation token">.</SPAN>Diamond<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>
  <SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">;</SPAN>

  <SPAN class="keyword token">return</SPAN> uniqueValueRenderer <SPAN class="keyword token">as</SPAN> CIMRenderer<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>‍</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>

Running the add-in using this input:

and then changes the colors using the lookup:

ColorFeatureByRelatedTable.ppkx.zip

ColorFeatureByRelatedTable.zip