回複：請PIJIANG和各位高手Confirm

1。我去年剛延期了H1B，拿到了I-797 Approval Notice，但今年年初用了AP入境，所以我的H1B Status就不存在了，那麽我的H4也就不可以去美國使領館簽H4簽證了？
-Are you still working for your original employer who sponsored you H1? If yes, you still can reinstate your H1 status by extension or going out of US to get a h1 visa.

2。如果我沒有H1B Status了，手中的I-797 Approval Notice 還有用嗎？可以用來申請H1B簽證嗎？移民局備忘錄裏隻說了Parolee可以extend H1B STATUS，沒說可以去申請VISA。
-Of course, you can use it for h1 visa application as long as the I-94 with this notice has not expires yet.

3。如果我可以申請H1B VISA，並用簽證回美國，H4去簽證就沒問題了吧？還需要在美國先申請個身份轉延（I-539）嗎（H4在Parolee之前是F1）？
-The original H4 holder needs to extend h4 or get H4 visa if he/she wants to reinstate the H4 status (do the same thing as h1 holder).