Slide rail assembly and bracket device thereof

A bracket device, comprising:

• a longitudinal wall;
• a mounting member movable relative to the longitudinal wall along a height direction of the longitudinal wall to be located at one of a first position and a second position;
• and
• a connecting member fixed relative to the longitudinal wall;
• wherein when the bracket device is rotated a predetermined angle to be switched from a first state to a second state, the mounting member is configured to be freely moved from the first position to the second position by gravity;
• wherein when the bracket device is in the first state, the mounting member is located at the first position and configured to be mounted to a first mounting hole of a post, and the connecting member is configured to be mounted to a second mounting hole of the post.