从回调到悬浮功能

Question

我有此功能：

fun createBiometricPrompt(
        activity: AppCompatActivity,
        processSuccess: (BiometricPrompt.AuthenticationResult) -> Unit,
        callback: BiometricCallback
    ): BiometricPrompt {
        var nbFailure = 0
        val executor = ContextCompat.getMainExecutor(activity)

        val callback = object : BiometricPrompt.AuthenticationCallback() {

            override fun onAuthenticationError(errCode: Int, errString: CharSequence) {
                super.onAuthenticationError(errCode, errString)
                Log.d(TAG, "errCode is $errCode and errString is: $errString")
            }

            override fun onAuthenticationFailed() {
                super.onAuthenticationFailed()
                Log.d(TAG, "User biometric rejected.")
                nbFailure++;
                if(nbFailure == MAX_BIOMETRICS_FAILURE){
                    nbFailure = 0
                    callback.onFailure()
                }
            }

使用回调回调：Biometriccallback ，它仅用于使用它来通知通过发送 callback.onfailure（）

回调发生的故障发生。在通过此操作的调用片段中：

fragment.kt

biometricPrompt =
                BiometricPromptUtils.createBiometricPrompt(requireActivity() as AppCompatActivity, ::encryptAndStoreServerToken, object: BiometricCallback {
                    override fun onFailure() {
                        biometricPrompt.cancelAuthentication()
                        viewModel.loginError.set("Error Biometrics")
                    }
                })

onfailure 被使用来取消过程并显示错误。

回调界面的定义为：

interface BiometricCallback {
    fun onFailure()
}

我被要求使用悬挂函数，而不是回调，但我不知道如何正确执行此操作。我应该使用Livedata吗？如果有的话，请帮助

谢谢

Answer 1

您可以使用 suppendCancellableCoroutine 或 supstendCoroutine 转换任何基于直接样式的基于回调的API，以使其更加kotlin友好友好，而且它提供了更多的封装，您将刚刚返回结果。仅在函数中处理

 suspend fun authenticate():BiomatricPrompt.AuthenticationResult? {
 return suspendCancelableCoroutine { continuation -> 
     biometricPrompt = BiometricPrompt(this, executor,
        object : BiometricPrompt.AuthenticationCallback() {
    override fun onAuthenticationError(errorCode: Int,
            errString: CharSequence) {
        super.onAuthenticationError(errorCode, errString)
        continuation.resume(null,null)
    }

    override fun onAuthenticationSucceeded(
            result: BiometricPrompt.AuthenticationResult) {
        super.onAuthenticationSucceeded(result)
         continuation.resume(result,null)
    }

    override fun onAuthenticationFailed() {
        super.onAuthenticationFailed()
         continuation.resume(null,null)
    }
   })
    promptInfo = BiometricPrompt.PromptInfo.Builder()
        .setTitle("Biometric login for my app")
        .setSubtitle("Log in using your biometric credential")
        .setNegativeButtonText("Use account password")
        .build()
    biometricPrompt.authenticate(promptInfo)
 }
}

您

val authenticationResult  = authenticate()
if(authenticationResult == null){
 //authentication failed
}else{
//authenticated successfully 
}

可以使用自定义对象作为结果类型来处理更多用例