If your soundbar does have an HDMI ARC input then you would have to turn this function on in the TV & Vizio set up menus. Most sound bars do not have ARC. Home theater in a box systems that have a disc player in them sometimes do.
Your Sharp TV probably has an optical audio output that you can connect to the sound bar. This is not controlled but the volume control of the TV so you just turn the TV volume all the way down. Select the optical input on the Vizio and use its' remote for volume.
I have a Sharp Aquos Q+ with Vizio 5.1 soundbar and it is possible to connect via HDMI ARC cable. One of the HDMI inputs will do ARC audio so you can only connect to that input. On mine, it's HDMI 3 but yours may be different (TV manual should tell you which HDMI input will do ARC). Also to get DDigital and DTS, you have to change audio setting on TV to "Bitstream". When it all works, you Sharp TV will automatically switch off speakers and connect to soundbar. Thus when you raise the volume on TV, it will actually raise it on the Soundbar.
I connected a vizio soundbar 5.1 system to my sharp 60" aquos smart tv with HDMI arc cables for better quality sound but i cannot turn off tv speakers and turn on the audio system sound.
I just bought a sharp TV and had the same issue,if you have the 5.1 Vizio sound bar all you have to do is turn off fixed tv speakers hook up sound bar with Digital Optical and then program remote. You have to use you vizio remote and your TV or cable remote also for this step.The steps are in your vizio book.You have to go to menu on the vizio remote press the learn volume down press play and press your TV or cable remote down at the same time as learning and then do the same for volume up and mute.Takes about 5 minutes once you know how.Hope it helps.