如何在添加android指纹验证的同时解决此错误？

Question

我正在开发一个应用程序，需要谷歌指纹验证登录我的应用程序。我的应用程序需要Android 4.4及更高版本（api级别> 19），但在api级别23以后添加了指纹验证。是否有可能使我的应用程序支持指纹认证与我提到的api级别19. 在我的gradle中，我将minsdk设置为19，当我将它设置为19时，崩溃并给出以下错误。但是当我换成23时就没问题。

E/AndroidRuntime: FATAL EXCEPTION: main 

Process: info.androidhive.fingerprint, PID: 15697 

java.lang.NoClassDefFoundError: Failed resolution of: 
Landroid/hardware/fingerprint/FingerprintManager; 

at info.androidhive.fingerprint.FingerprintActivity.onCreate(FingerprintActivity.java:45) 

at android.app.Activity.performCreate(Activity.java:6010) 

at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1129) 

at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2292) 

at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2413) 

at android.app.ActivityThread.access$800(ActivityThread.java:155) 

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317) 

at android.os.Handler.dispatchMessage(Handler.java:102) 

at android.os.Looper.loop(Looper.java:135) 

at android.app.ActivityThread.main(ActivityThread.java:5343) 

at java.lang.reflect.Method.invoke(Native Method) 

at java.lang.reflect.Method.invoke(Method.java:372) 

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905) 

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700) 

Caused by: java.lang.ClassNotFoundException: Didn't find class "android.hardware.fingerprint.FingerprintManager" on path: DexPathList[[zip file "/data/app/info.androidhive.fingerprint-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]] 
                       at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) 
                       at java.lang.ClassLoader.loadClass(ClassLoader.java:511) 
                       at java.lang.ClassLoader.loadClass(ClassLoader.java:469) 
                       at info.androidhive.fingerprint.FingerprintActivity.onCreate(FingerprintActivity.java:45)  
                       at android.app.Activity.performCreate(Activity.java:6010)  
                       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1129)  
                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2292)  
                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2413)  
                       at android.app.ActivityThread.access$800(ActivityThread.java:155)  
                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317)  
                       at android.os.Handler.dispatchMessage(Handler.java:102)  
                       at android.os.Looper.loop(Looper.java:135)  
                       at android.app.ActivityThread.main(ActivityThread.java:5343)  
                       at java.lang.reflect.Method.invoke(Native Method)  
                       at java.lang.reflect.Method.invoke(Method.java:372)  
                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)  
                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)  
                      Suppressed: java.lang.ClassNotFoundException: android.hardware.fingerprint.FingerprintManager 
                       at java.lang.Class.classForName(Native Method) 
                       at java.lang.BootClassLoader.findClass(ClassLoader.java:781) 
                       at java.lang.BootClassLoader.loadClass(ClassLoader.java:841) 
                       at java.lang.ClassLoader.loadClass(ClassLoader.java:504) 
                        ... 15 more 
                      Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available 

Answer 1

如果你想在应用程序API级别小于23使用FingerpintManager我们不能用API使用FingerpintManager小于23的minSdkVersion这个FingerpintManager为23

，您可以考虑使用FingerprintManagerCompat ，其行为就好像没有指纹传感器在API等级小于23的情况下可用。

欲了解更多信息，请查看链接以及示例。

https://developer.android.com/reference/android/support/v4/hardware/fingerprint/FingerprintManagerCompat.html 

https://github.com/AMykich/Android-Fingerprint-API