Android java转成kotiln的报错笔记
1.java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=0, data=null} to activity {com.example.c.dpcode/com.example.c.dpcode.activity.MainActivity}: java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull, parameter data
at android.app.ActivityThread.deliverResults(ActivityThread.java:5078)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:5120)
at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:49)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2199)
at android.os.Handler.dispatchMessage(Handler.java:112)
at android.os.Looper.loop(Looper.java:216)
at android.app.ActivityThread.main(ActivityThread.java:7625)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987)
Caused by: java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull, parameter data
at com.example.c.dpcode.activity.MainActivity.onActivityResult(Unknown Source:8)
at android.app.Activity.dispatchActivityResult(Activity.java:7797)
at android.app.ActivityThread.deliverResults(ActivityThread.java:5071)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:5120)
at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:49)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2199)
at android.os.Handler.dispatchMessage(Handler.java:112)
at android.os.Looper.loop(Looper.java:216)
at android.app.ActivityThread.main(ActivityThread.java:7625)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987)
报错信息：是使用询问的方式去打开蓝牙引发的问题（点击允许打开蓝牙不会报错，拒绝打开蓝牙才会报错的）
val enableBtIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT)开始以为是常量REQUEST_ENABLE_BT的报错的，但网上查了下资料最后发现不是这个报错的。
最后找到的原因是：
转成kotiln后是下面这个方法这样的
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent)报错之处在于data可能为null，所以会闪退，改成
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?)这样就不会闪退了2.接口文件使用了泛型T，但在Activity中建立这个接口对象时，从java转Kotiln要修改部分信息
开始以为直接使用Objects就可以，但可能会和接口冲突。最后使用*就没事了
lateinit var userSubscriber: SubscriberOnNextListener<*>
lateinit是修饰符，作用是不用在定义的时候赋值。