如何设计一个复杂的课程,在Kotlin将来可以轻松扩展一些课程？

Question

我是Kotlin的初学者,我使用代码A来定义一个复杂的类MDetail,并使用代码B来创建一个对象aMDetail1,它可以工作.

但数据结构是太糟糕了扩大,如果我有一个新的数据类如ScreenDef中MDetail 就像代码C,所有旧的代码必须rewriten.

对于包含某些类的复杂类,是否有良好的数据结构？我希望将来数据构建可以轻松扩展!

代码A.

data class BluetoothDef(val Status:Boolean=false)
data class WiFiDef(val Name:String, val Status:Boolean=false)

data class MDetail (
        val _id: Long,
        val bluetooth: BluetoothDef,
        val wiFi:WiFiDef
)

代码B.

var mBluetoothDef1= BluetoothDef()
var mWiFiDef1= WiFiHelper(this).getWiFiDefFromSystem()
var aMDetail1= MDetail(7L,mBluetoothDef1,mWiFiDef1)

代码C.

data class BluetoothDef(val Status:Boolean=false)
data class WiFiDef(val Name:String, val Status:Boolean=false)
data class ScreenDef(val Name:String, val size:Long)
... 

data class MDetail (
        val _id: Long,
        val bluetooth: BluetoothDef,
        val wiFi:WiFiDef
        val aScreenDef:ScreenDef        
        ...
)

以下代码基于s1m0nw1所说的内容,我认为将来很容易扩展.谢谢!

还有其他更好的方法吗？

版本1代码

interface DeviceDef

data class BluetoothDef(val Status: Boolean = false) : DeviceDef
data class WiFiDef(val Name: String, val Status: Boolean = false) : DeviceDef
data class ScreenDef(val Name: String, val size: Long) : DeviceDef

class MDetail(val _id: Long, val devices: MutableList<DeviceDef>) {
    inline fun <reified T> getDevice(): T {
        return devices.filterIsInstance(T::class.java).first()
    }
}

class UIMain : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.layout_main)

        val btD = BluetoothDef(true)
        val wfD = WiFiDef("MyWifi")
        val xSc = ScreenDef("MyScreen", 1)
        val m = MDetail(7L, mutableListOf(btD, wfD, xSc))


        handleBluetoothDef(m.getDevice<BluetoothDef>())
        handleWiFiDef(m.getDevice<WiFiDef>())
        handleScreenDef(m.getDevice<ScreenDef>())
    }

    fun handleBluetoothDef(mBluetoothDef:BluetoothDef){ }    
    fun handleWiFiDef(mWiFiDef:WiFiDef){ }    
    fun handleScreenDef(mScreenDef:ScreenDef){ }
}

版本2代码(扩展)

interface DeviceDef

data class BluetoothDef(val Status: Boolean = false) : DeviceDef
data class WiFiDef(val Name: String, val Status: Boolean = false) : DeviceDef
data class ScreenDef(val Name: String, val size: Long) : DeviceDef

data class TimeLine(val Name: String): DeviceDef  //Extend

class MDetail(val _id: Long, val devices: MutableList<DeviceDef>) {
    inline fun <reified T> getDevice(): T {
        return devices.filterIsInstance(T::class.java).first()
    }
}

class UIMain : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.layout_main)

        val btD = BluetoothDef(true)
        val wfD = WiFiDef("MyWifi")
        val xSc = ScreenDef("MyScreen", 1)

        val aTe = TimeLine("MyTimeline")  //Extend

        val m = MDetail(7L, mutableListOf(btD, wfD, xSc,aTe)) //Modified


        handleBluetoothDef(m.getDevice<BluetoothDef>())
        handleWiFiDef(m.getDevice<WiFiDef>())
        handleScreenDef(m.getDevice<ScreenDef>())

        handleTimeLine(m.getDevice<TimeLine>()) //Extend
    }

    fun handleBluetoothDef(mBluetoothDef:BluetoothDef){}    
    fun handleWiFiDef(mWiFiDef:WiFiDef){ }    
    fun handleScreenDef(mScreenDef:ScreenDef){ }           
    fun handleTimeLine(mTimeLine:TimeLine){}  //Extend

救命

我必须用open类替换接口,因为我无法从json字符串GSON反序列化MDetail对象.

但乐趣inline fun <reified T> getDevice(): T{ }无法返回正确的结果,我该如何修改？谢谢!

open class DeviceDef

data class BluetoothDef(val status:Boolean=false):  DeviceDef()
data class WiFiDef(val name:String, val status:Boolean=false) : DeviceDef()

data class MDetail(val _id: Long, val deviceList: MutableList<DeviceDef>)
{
    inline fun <reified T> getDevice(): T {        
        return deviceList.filterIsInstance(T::class.java).first()
    }
}

Answer 1

每次向 中添加新属性时MDetail，请将新属性标记为可为空并将默认值设置为 null。像这样

data class MDetail (
        val _id: Long,
        val bluetooth: BluetoothDef,
        val wiFi: WiFiDef,
        val screen: ScreenDef? = null,
        ...
)

不要忘记在创建新实例时提供特定的属性名称，如下所示

var aMDetail1= MDetail(7L, mBluetoothDef1, mWiFiDef1, screen = mScreenDef1)