在这种情况下，确实有一个 API 和回调供您使用。您正在寻找的包是 API 级别 28+的Biometrics包或 API 级别 23-27 的指纹包。
我所指的回调可以在这里找到API 28+ 和这里API 23-27。
下面是一些关于如何初始化回调的示例代码：
/**
* Helper class for authentication callback
*/
@RequiresApi(api = Build.VERSION_CODES.M)
private class FingerprintHandler extends FingerprintManager.AuthenticationCallback {
private FingerprintHandler(){}
/**
* Called when an unrecoverable error has been encountered and the operation is complete.
* No further callbacks will be made on this object.
* @param errMsgId An integer identifying the error message
* @param errString A human-readable error string that can be shown in UI
*/
@Override
public void onAuthenticationError(int errMsgId, CharSequence errString) {
//Authentication error. The 'errString' is meant to be displayed to the user
//Handle logic here
}
/**
* Called when a fingerprint is valid but not recognized.
*/
@Override
public void onAuthenticationFailed() {
//Authentication failed (Fingerprints don't match ones on device)
//Handle logic here
}
/**
* Called when a recoverable error has been encountered during authentication. The help
* string is provided to give the user guidance for what went wrong, such as
* "Sensor dirty, please clean it."
* @param helpMsgId An integer identifying the error message
* @param helpString A human-readable string that can be shown in UI
*/
@Override
public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
//Non-Fatal error (IE moved finger too quickly). The helpString can be displayed to the user to help them retry.
//Handle logic here
}
/**
* Called when a fingerprint is recognized.
* @param result An object containing authentication-related data
*/
@Override
public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
//Authentication Succeeded. They are good to go and it matches the stored one
//Handle logic here
}
}
如果上面的代码不足以让你动起来，这里是我的一个类中的一些示例用法。
关于使用警报或显示，如果我不想阻塞屏幕，我只需将回调信息与对话框或屏幕文本视图结合使用。
