为什么我的蓝牙适配器使应用程序崩溃

Question

Im trying to learn how to just enable and disable Bluetooth through my application. So I have been writing a small code for this. When I run the application on a simulator the code works and it enables and disables the Bluetooth. When I run it on my phone it crashing.

private void initBluetooth() {
    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (bluetoothAdapter == null) {
        Toast.makeText(context, "No Bluetooth found", Toast.LENGTH_SHORT).show();
        finish();
    }
}

private void enableDisableBluetooth() {
    if (bluetoothAdapter.isEnabled()) {
        bluetoothAdapter.disable();
    } else {
        bluetoothAdapter.enable();
    }
}

<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />

2022-05-24 12:45:12.536 32020-32020/com.example.bluetoothtest E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.bluetoothtest, PID: 32020
    java.lang.SecurityException: Need android.permission.BLUETOOTH_CONNECT permission for AttributionSource { uid = 10467, packageName = com.example.bluetoothtest, attributionTag = null, token = android.os.BinderProxy@ee66382, next = null }: disable
        at android.os.Parcel.createExceptionOrNull(Parcel.java:2437)
        at android.os.Parcel.createException(Parcel.java:2421)
        at android.os.Parcel.readException(Parcel.java:2404)
        at android.os.Parcel.readException(Parcel.java:2346)
        at android.bluetooth.IBluetoothManager$Stub$Proxy.disable(IBluetoothManager.java:1046)
        at android.bluetooth.BluetoothAdapter.disable(BluetoothAdapter.java:2270)
        at com.example.bluetoothtest.MainActivity.enableBluetooth(MainActivity.java:108)
        at com.example.bluetoothtest.MainActivity.onOptionsItemSelected(MainActivity.java:55)
        at android.app.Activity.onMenuItemSelected(Activity.java:4401)
        at androidx.fragment.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:352)
        at androidx.appcompat.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:264)
        at androidx.appcompat.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:109)
        at androidx.appcompat.app.AppCompatDelegateImpl.onMenuItemSelected(AppCompatDelegateImpl.java:1185)
        at androidx.appcompat.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:834)
        at androidx.appcompat.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:158)
        at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:985)
        at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:975)
        at androidx.appcompat.widget.ActionMenuView.invokeItem(ActionMenuView.java:625)
        at androidx.appcompat.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:151)
        at android.view.View.performClick(View.java:7792)
        at android.widget.TextView.performClick(TextView.java:16045)
        at android.view.View.performClickInternal(View.java:7769)
        at android.view.View.access$3800(View.java:910)
        at android.view.View$PerformClick.run(View.java:30184)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loopOnce(Looper.java:226)
        at android.os.Looper.loop(Looper.java:313)
        at android.app.ActivityThread.main(ActivityThread.java:8641)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:567)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1133)
     Caused by: android.os.RemoteException: Remote stack trace:
        at com.android.server.BluetoothManagerService.checkPermissionForDataDelivery(BluetoothManagerService.java:5019)
        at com.android.server.BluetoothManagerService.checkConnectPermissionForDataDelivery(BluetoothManagerService.java:5037)
        at com.android.server.BluetoothManagerService.checkBluetoothPermissions(BluetoothManagerService.java:1503)
        at com.android.server.BluetoothManagerService.disable(BluetoothManagerService.java:1930)
        at android.bluetooth.IBluetoothManager$Stub.onTransact(IBluetoothManager.java:473)
2022-05-24 12:45:12.584 32020-32020/com.example.bluetoothtest I/Process: Sending signal. PID: 32020 SIG: 9

Answer 1

With the new update on Android 12 the bluetooth permissions are separated in multiple pemrissions. In your manifest you declared BLUETOOTH_CONNECT, so first you need to request BLUETOOTH_CONNECT permission in your activity or fragment.

The BLUETOOTH_ADVERTISE, BLUETOOTH_CONNECT, and BLUETOOTH_SCAN permissions are runtime permissions. Therefore, you must explicitly request user approval in your app before you can look for Bluetooth devices.

Target Android 12 or higher