Identify results for WMS features differ from expected

Description

When you use the Identify tool to query a WMS service feature, the results in the Identify results dialog may be different than expected.

1. Results are not displayed in the usual tabular grid.

2. Using the <Top-most Layer> option, doesn't work as expected. The result is empty.

3. Using the <All layers> option, doesn't work as expected. The tree view includes all WMS service sublayers even if there are no features present at the point of identification.

4. The result for a particular WMS service sublayers is empty.

Note:
WMS Features have no primary display field.  The WMS feature in the left pane tree view will always be refered to as 'WMS Feature(s)'. 

Cause

1. Identify results for WMS services are displayed using an Internet Explorer control embedded in the Identify window.

This is because identify results returned by a WMS service can be in any of several formats, such as field/value pairs, HTML or an image.

The Identify window will display whatever is returned from the service.

2. When you use the <Top-most Layer> option the Identify Tool will only identify features from the top-most sublayer in the WMS service's drawing hierarchy. A result will be returned even if there are no features present for this sublayer.

3 & 4. At version 1.1.1 the WMS specification does not provide any tags or formats that help ArcMap determine whether there are features to identify at that location or not. Therefore, <All layers> will return results for all WMS service sublayers and there will be a result even if there is no feature present for a particular sublayer.

Solution or Workaround