Electromagnetic stylus with auto-switching

An electromagnetic stylus comprising:

• a body comprising a first shell and a second shell telescopically sleeved on the first shell;
• a core received in and having a nib end extending out of the first shell;
• and
• an induction coil sleeved on one end of the core and received in the first shell;
• wherein the first shell is made of material without electromagnetic wave shielding capability, the second shell is made of material with electromagnetic wave shielding capability, and the second shell is configured to slide along the first shell between, a first position where a part of the induction coil is shielded so that the electromagnetic stylus cannot receive or send electromagnetic waves, and a second position where the induction coil is unshielded so that the electromagnetic stylus can receive or send electromagnetic waves.