我是Kotlin的初学者,我使用代码A来定义复杂的类MDetail,并使用代码B来创建一个对象aMDetail1,它可以工作.
但是数据结构太糟糕了,如果我像MD C一样在MDetail中包含一个新的数据类,比如ScreenDef,那么所有旧的代码都必须重写.
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 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 size: Long) : DeviceDef
data class TimeLine(val Name: String): DeviceDef //Extend
class MDetail(val _id: Long,1)
val aTe = TimeLine("MyTimeline") //Extend
val m = MDetail(7L,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.
但有趣的内联乐趣< reified T> getDevice()：T {}无法返回正确的结果,我该怎么修改？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()
}
}
解决方法
我建议执行以下操作：您的设备(Wifi,蓝牙等)应该通过接口(至少作为标记)抽象,可以命名为DeviceDef.
interface DeviceDef data class BluetoothDef(val Status: Boolean = false) : DeviceDef data class WiFiDef(val Name: String,val size: Long) : DeviceDef
MDetail类可以使用这些设备的变量列表进行实例化,因此在添加新设备(如ScreenDef)时不需要进行任何修改：
class MDetail(val _id: Long,val devices: List<DeviceDef>)
在MDetail中,您可以提供过滤这些设备的方法：
class MDetail(val _id: Long,val devices: List<DeviceDef>) {
inline fun <reified T> getDevice(): T {
return devices.filterIsInstance(T::class.java).first()
}
}
现在,使用WifiDef非常简单：
fun main(args: Array<String>) {
val btD = BluetoothDef()
val wfD = WiFiDef("")
val m = MDetail(7L,listOf(btD,ScreenDef("",1)))
println(m.getDevice<WiFiDef>())
}
我希望这有帮助.如果没有,您可能需要提供有关MDetail应如何工作的更多详细信息.
