在我的课堂上有很多有趣的事情：
main = withFile "index.html" WriteMode writeContents
where writeContents file = mapM_ (hPutStrLn file) setHTML
尝试在P版本上运行都可以正常运行，它调用了有趣的@TargetApi(Build.VERSION_CODES.P)
override fun showFingerprintDialog() {
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) displayBiometricPrompt()
else FingerprintDialog().show(supportFragmentManager, null)
}
@RequiresApi(Build.VERSION_CODES.P)
private fun displayBiometricPrompt() {
Log.d("some", "displayBiometricPrompt")
val biometricPrompt = BiometricPrompt.Builder(AppResources.appContext)
.setTitle("title")
.setSubtitle("subTitle")
.setDescription("description")
.setNegativeButton("Cancel", AppResources.appContext?.mainExecutor,
DialogInterface.OnClickListener { dialogInterface, i -> Log.d("some", "biometricPrompt") })
.build()
val cancellationSignal = CancellationSignal()
cancellationSignal.setOnCancelListener {
Toast.makeText(
AppResources.appContext, "onCancel", Toast.LENGTH_SHORT).show()
}
biometricPrompt.authenticate(cancellationSignal, AppResources.appContext?.mainExecutor, authenticationCallBack)
}
private val authenticationCallBack = object : BiometricPrompt.AuthenticationCallback() {
override fun onAuthenticationError(errorCode: Int, errString: CharSequence?) {
super.onAuthenticationError(errorCode, errString)
Log.d("some", "onAuthenticationError")
}
override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult?) {
super.onAuthenticationSucceeded(result)
Log.d("some", "onAuthenticationSucceeded")
}
override fun onAuthenticationHelp(helpCode: Int, helpString: CharSequence?) {
super.onAuthenticationHelp(helpCode, helpString)
Log.d("some", "onAuthenticationHelp")
}
override fun onAuthenticationFailed() {
super.onAuthenticationFailed()
Log.d("some", "onAuthenticationFailed")
}
}
，然后在脚本中进一步运行，一切正常。
但是，如果我尝试在较低的版本上运行，则会引发以下错误，即在声明变量displayBiometricPrompt()时。
并得到下一个错误：
authenticationCallBack