Question

我有一个进行蓝牙连接的类，并从与汽车相连的OBD蓝牙加密狗获取PID。但是，当调用获取RPM的方法时，我有一个关于不初始化该属性的异常。

class BluetoothOBDManager : OBDManager {
    lateinit var context: Context
    private lateinit var input: InputStream
    private lateinit var output: OutputStream
    private lateinit var rpmCommand: RPMCommand
    private lateinit var coolantTempCommand: EngineCoolantTemperatureCommand
    private lateinit var airIntakeTempCommand: AirIntakeTemperatureCommand
    private lateinit var mmSocket : BluetoothSocket

    fun connect(deviceString: String) {
        var adapter: BluetoothAdapter = getDefaultAdapter()
        val device = adapter.getRemoteDevice(deviceString)
        val uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB")
        val mmSocket:BluetoothSocket=device.createRf....Record(uuid)

        mmSocket.let { socket ->
                socket.connect()
            }

        input = mmSocket.inputStream
        output = mmSocket.outputStream
        if (mmSocket.isConnected) {
            println("output.write =1")
            output.write(1)
        }
        rpmCommand = RPMCommand() //This is the INIT of the propert
    }

    override fun getCurrentRpm(): Int {
        rpmCommand.run(input, output) // This line throughs the EXCEPTION
        return rpmCommand.rpm
    }
}

这是我从另一个类调用该方法的方式

BluetoothOBDManager().connect(deviceString)
            var rpm  = BluetoothOBDManager().getCurrentRpm()
            rpmTextView.setText(rpm)

例外

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: gr.obd.logger, PID: 17486
    kotlin.UninitializedPropertyAccessException: lateinit property rpmCommand has not been initialized

我尝试初始化方法中的属性，但没有运气

  override fun getCurrentRpm(): Int {
        rpmCommand = RPMCommand()
        rpmCommand.run(input, output) // This line throughs the EXCEPTION
        return rpmCommand.rpm
    }

Answer 1

BluetoothOBDManager().connect(deviceString)
        var rpm  = BluetoothOBDManager().getCurrentRpm()

您的代码创建一个BluetoothOBDManager，将其连接（初始化rpmCommand），然后将其丢弃，创建一个未初始化所有内容的 new BluetoothOBDManager并尝试致电getCurrentRpm。可能应该是

val obdManager = BluetoothOBDManager()
obdManager.connect(deviceString)
val rpm = obdManager.getCurrentRpm()

这并不能说明您为什么得到

我试图初始化方法中的属性，但是没有运气

但是真正的不应该发生；我预计会有其他问题。

如何解决“ lateinit属性YYY尚未初始化”

1 个答案: