Hi Dominique,
Thank you for your help.
I've tried what you have suggested but unfortunately it does not help. What you've suggested is related to ArcGISDynamicMapServiceLayer as a whole, so if I do:
<esri:ArcGISDynamicMapServiceLayer ID="USAID_Layers"
Initialized="ArcGISDynamicMapServiceLayer_Initialized"
Opacity="0.3" DisableClientCaching="True"
/>
I will see the legend of all layers ,in the legend of the ArcGISDynamicMapServiceLayer, transparent.
The thing is that I'm interested in individual layers within the ArcGISDynamicMapServiceLayer (few polygon layers) that will be transparent (with opacity). I thought that if I will define these layers transparent in the MXD and publish it, it will look the same in the legend of the application but it doesn't.
As a result, Esri opened a NIM for that :Bug ID: # NIM091488
Synopsis Transparency of Legends/TOC not honored in Map Service
The ArcGISDynamicMapServiceLayer exposes very few details for each individual layer in the service - minScale, maxScale, name, subLayersID, defaultVisibility (you can see in the attached file) so I cannot grab the opacity.
Thanks a lot,
Miri