If I have a box with a gradient stroke (as an example) and I want to then fill it, if I use the eyedropper to grab the color from another object, it overrides and deletes the stoke. I would like to be able to use the eyedropper on fill or stroke without deleting it's counterpart. Right now it's a long process of clicking off my shape, eyedropping the color, copying the color value, reselecting the object, double clicking the fill or stroke, and pasting in the value. It adds up to a lot of time lost for something that should be much more simple.
To make Eyedropper pick and apply only fill, without modifying the stroke, you need to open the tool’s options, and uncheck the ‘Focal Stroke’ option in the left column. This will force Illustrator to ignore the stroke from the source object, and your target object will keep its original stroke.
Use other options there to fine tune the tool to your needs.
There is a similar resolved request that is about the same thing — https://illustrator.uservoice.com/forums/333657/suggestions/38241262