• Microbit 按钮
  • Properties
  • Methods
  • Events

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Microbit 按钮

The Microbit_Button extension provides App Inventor with information about the state of the BBC micro:bit’s buttons. Developers can use this extension to request updates for when a user presses a button or read the current state of the buttons. The buttons have three states:

• 0 - up
• 1 - down
• 2 - long pressed

More links:<ul><li>Download a sample projects for the micro:bit onboard buttons.</li><li>View the how to instructions for the micro:bit onboard buttons</li></ul>

Properties

• BluetoothDevice – The BluetoothLE component connected to the micro:bit device (setter).

Methods

• ReadButtonAState – Read the current state of the micro:bit’s A button. After a successful read, the ButtonAStateReceived event will be run.

• ReadButtonBState – Read the current state of the micro:bit’s B button. After a successful read, the ButtonBStateReceived event will be run.

• RequestButtonAStateUpdates – Request updates to the state of the micro:bit’s A button. After requesting updates, the ButtonAStateReceived will be run whenever the micro:bit reports a button state change to the app. Pressing and holding the button will result in a second event with the value 2 to indicate a long press.

• RequestButtonBStateUpdates – Request updates to the state of the micro:bit’s B button. After requesting updates, the ButtonBStateReceived will be run whenever the micro:bit reports a button state change to the app. Pressing and holding the button will result in a second event with the value 2 to indicate a long press.

• StopButtonAStateUpdates – Stop receiving updates about the state of the micro:bit’s A button. Note that there may be pending updates that have not been processed that will result in ButtonAStateReceived

• StopButtonBStateUpdates – Stop receiving updates about the state of the micro:bit’s B button. Note that there may be pending updates that have not been processed that will result in ButtonBStateReceived.

Events

• ButtonAStateReceived – After performing a read or request for updates, the ButtonAStateReceived event will be run with information about the button state.

Parameters:

• Button_State_Value (number) — The state of the micro:bit’s A button; 0 for released, 1 for pressed, 2 for long-pressed.

• ButtonBStateReceived – After performing a read or request for updates, the ButtonBStateReceived event will be run with information about the button state.

Parameters:

• Button_State_Value (number) — The state of the micro:bit’s B button; 0 for released, 1 for pressed, 2 for long-pressed.