すべての電話をブロックする方法は、SMSとネットワークを許可しますか。 -- 2.3-gingerbread フィールド と calls フィールド と privacy フィールド android 関連 問題

It's kinda disturbing when people keep calling me during work or meetings, but to me it's okay if I receive short messages or Whatsapp message because I can reply them few minutes later in a short break. I'm new Android user and wonder if my phone could do that for me.

You can use the tried and tested Call Barring method

1. Go to Settings
2. Select Call Settings
3. Look for Call barring
4. Now select All Incoming
5. Enter your default PIN (1234)

There, all incoming calls will be blocked. You may still be able to place calls unless you barred that too.

This feature is carrier network dependent and it already exists in the dumbphone era. Still useful though.

Try this:

1. Go to Contact list
2. Select contact
3. Open menu, and press the "Block" button (or "Add to blocklist")

I also found Call Guard in the Play Store. Maybe you take a look at it.

(At least in some phones, for example LG G3) there's an option for this:

Settings / Networks / Call / (select Common if this is dual SIM device) / Call reject. You can select Reject all calls in Call reject mode to reject all calls automatically.

Go to call forwarding menu and forward all calls to voicemail