Onclick没有在android studio中使用kotlin做出响应

Question

我是kotlin的新手。在这里，我正在为我的应用程序实现登录屏幕，并使用kotlin如下所示使用xml文件实现类，但是当我点击按钮或textview onclick时没有响应。请帮我解决这个问题。

import android.content.Intent
import android.support.v7.app.AppCompatActivity
import android.os.*
import android.util.Log
import android.view.View
import android.widget.Button
import android.widget.TextView
import android.widget.Toast
import butterknife.BindView
import butterknife.ButterKnife
import butterknife.OnClick

class login : AppCompatActivity(), View.OnClickListener {

    @BindView(R.id.title) var title: TextView? = null
    @BindView (R.id.email)  var email : TextView? = null
    @BindView (R.id.password)  var pass : TextView? = null
    @BindView (R.id.tv_fp)  var fp : TextView? = null
    @BindView (R.id.tv_register) var register : TextView? = null
    @BindView (R.id.btn_login )  var login : Button? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)
        ButterKnife.bind(this)
        // change to register!!.setOnClickListener(this) to make sure your view is injected
        register?.setOnClickListener(this)
        login?.setOnClickListener(this)
    }
    //                       v--- change the parameter type View? to View, it is never be null     
    override fun onClick(p0: View?) {
        // v--- remove it
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
        //   v--- remove the redundant safe-call ?. 
        if(p0?.id == R.id.tv_register){
            Log.e("login", "i")
            var intent  = Intent(this@login,  signin:: class.java)
            startActivity(intent)
        }
        if(p0?.id == R.id.btn_login){
             Toast.makeText(this, "Login Button clicked", Toast.LENGTH_SHORT)
        }
    }
}

和这个类的布局文件如下，我使用constrainedLayout

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="20dp">
    <android.support.design.widget.TextInputEditText
        android:id="@+id/email"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="Email id"
        android:textCursorDrawable="@drawable/cursor_color"
        android:backgroundTint="@color/skyBlue"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        android:layout_marginTop="100dp"
        app:layout_constraintHorizontal_bias="0.0"
        android:inputType="textEmailAddress"/>

    <android.support.design.widget.TextInputEditText
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="Password"
        android:textCursorDrawable="@drawable/cursor_color"
        android:id="@+id/password"
        app:layout_constraintStart_toStartOf="parent"
        android:layout_marginTop="8dp"
        app:layout_constraintTop_toBottomOf="@+id/email"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        android:inputType="textPassword"/>

    <Button
        android:id="@+id/btn_login"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Login"
        app:layout_constraintStart_toStartOf="parent"
        android:layout_marginTop="36dp"
        android:background="@color/yellow"
        android:textStyle="bold"
        app:layout_constraintTop_toBottomOf="@+id/password"
        android:layout_marginStart="4dp" />

    <TextView
        android:id="@+id/tv_fp"
        android:layout_width="171dp"
        android:layout_height="22dp"
        android:text="FORGOT PASSWORD?"
        android:background="?attr/selectableItemBackground"
        tools:layout_editor_absoluteY="301dp"
        android:layout_marginStart="8dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/tv_register"
        android:layout_marginTop="6dp"
        android:layout_marginBottom="7dp"
        app:layout_constraintBottom_toTopOf="@+id/btn_login" />

    <TextView
        android:id="@+id/tv_register"
        android:layout_width="156dp"
        android:layout_height="18dp"
        android:layout_marginStart="8dp"
        android:text="Register"
        android:background="?attr/selectableItemBackground"
        android:gravity="right"
        app:layout_constraintStart_toEndOf="@+id/tv_fp"
        app:layout_constraintTop_toTopOf="@+id/button"
        android:layout_marginTop="58dp"
        app:layout_constraintBottom_toBottomOf="@+id/btn_login"
         />
</android.support.constraint.ConstraintLayout>