Raise expectations

Can anyone think of a phrase that means to falsely raise someone's expectations, only to possibly dash them again?

"Bait and switch" comes to mind --- it's the name of a swindler's ploy which has passed into general usage, seeming to offer some attractive "bait" which is switched at the last minute for something worthless.

On the other hand, if you don't mean to imply a malicious intent to deceive, you could simply say that someone "gave false hope". Or more colloquially, "It's all moonshine" --- in this case the word "moonshine" refers not to untaxed liquor but to the way a nimbus of soft light makes any prospect appear lovely, which in plain sight may turn out to be a wasteland or a garbage dump, or worse.

The phrases that I can think of don't quite get it. Building castles in the air refers to self-delusion. Leading someone down the garden path -- seduction. Blowing smoke up one's a** (or pumping sunshine up one's shirt) -- flattery.

"Let someone down" is the best I can think of. Pamela

Everybody sing:

Why do you build me up (build me up)
Buttercup, baby,
Just to let me down (let me down)...

-- Album Title: Billboard Greatest Hits of 1969
Prime Artist: The Foundations