Various embodiments provide a method performed by a handheld device and the handheld device, where a USB interface of the handheld device with an infrared remote control application is connected to a port of a display device by using an adapter cable, the handheld device determines that a preset source port of the display device is not the connected port, and automatically switches the source port to the connected port by using the infrared remote control application. The handheld device sends to-be-displayed content of the handheld device to the display device by using the USB interface, the adapter cable, and the connected port to enable the display device to display the to-be-displayed content.