View 属性代理

ViewPropertiesDelegate.kt

import android.view.View
import android.widget.Spinner
import android.widget.TextView
import kotlin.reflect.KProperty

/**
 * View 属性代理
 *
 * @param V : View
 * @param T
 * @property v V
 * @property getter
 * @property setter
 * @constructor
 */
open class ViewPropertiesDelegate<V : View, T>(
        val v: V,
        val getter: (v: V) -> T,
        val setter: (t: T, v: V) -> Unit
) {

    operator fun getValue(thisRef: Any?, property: KProperty<*>): T = getter(v)

    operator fun setValue(thisRef: Any?, property: KProperty<*>, t: T) = setter(t, v)
}


class TextViewDel(v: TextView) : ViewPropertiesDelegate<TextView, String>(v,
        setter = { t, v -> v.text = t },
        getter = { it.text.toString() }
)

class SpinnerDel(v: Spinner) : ViewPropertiesDelegate<Spinner, Int>(
        v, setter = { t, v -> v.setSelection(t) },
        getter = { v -> v.selectedItemPosition }
)

Usage:

val userView = view.user_view
val pwdView = view.pwd_view
var user by TextViewDel(userView)
var pwd by TextViewDel(pwdView)

//....
user = "123"
val account = Account(user, pwd)