  In an insightful approach, Robinson and Wilczek proposed that Hawking
radiation can be obtained as the compensation of a breakdown of general
covariance and gauge invariance and the radiation is a black body radiation at
Hawking temperature. We apply this method to two types of black holes in three
dimensional spacetime, which share the general form of the metric in that the
$tt$ component of the metric is not inverse of the $rr$ component of the
metric. First one is the warped $AdS_3$ black hole in three dimensional
topologically massive gravity with negative cosmological constant, and second
one is the charged rotating black hole in three dimensions.
