android.support.v7中的dialogpreference导致override nothing错误

代码A运行良好,但是当我替换 import android.preference.DialogPreference 具有 import android.support.v7.preference.DialogPreference

为什么?

误差

onCreateDialogView() override nothing
onDialogClosed() override nothing
showDialog() override nothing

代码A

import android.preference.DialogPreference
import android.app.AlertDialog
import android.content.Context
import android.os.Bundle
import android.util.AttributeSet
import android.view.View
import info.dodata.mirror.R
import android.widget.EditText
import org.jetbrains.anko.*
import utility.PreferenceTool

class DialogChangePassword(context: Context, attrs: AttributeSet) : DialogPreference(context, attrs) {

    private lateinit var mView: View
    private lateinit var mContext: Context

    init {
        dialogLayoutResource = R.layout.item_custom_password_dialog
    }

    override fun onCreateDialogView(): View {
        mView = super.onCreateDialogView()
        mContext=mView.context
        return mView
    }

    override fun onDialogClosed(positiveResult: Boolean) {
        super.onDialogClosed(positiveResult)
    }

    override fun showDialog(state: Bundle?) {
        super.showDialog(state)

        val d = dialog as AlertDialog
        d.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener {           
               d.dismiss()           
        }
    }


}