Slide rail mechanism

A slide rail mechanism, comprising:

• a fixed rail;
• a movable rail and a supporting rail movable relative to the fixed rail;
• an engaging member movably mounted to one of the supporting rail and the movable rail;
• a predetermined structure arranged on the other one of the supporting rail and the movable rail;
• and
• an operating member;
• wherein when the movable rail and the supporting rail are retracted relative to the fixed rail, the movable rail and the supporting rail are respectively located at a first retracted position and a second retracted position relative to the fixed rail;
• wherein when the movable rail is located at the first retracted position and when the operating member is located at a first predetermined position, the movable rail is movable from the first retracted position along an opening direction and unable to drive the supporting rail to synchronously move from the second retracted position along the opening direction;
• wherein when the movable rail is located at the first retracted position and when the operating member is operated to move from the first predetermined position to a second predetermined position, the engaging member is configured to be moved to switch from a first state to a second state, such that the engaging member is engaged with the predetermined structure, in order to allow the movable rail to drive the supporting rail to synchronously move from the second retracted position along the opening direction when the movable rail is moved from the first retracted position along the opening direction.