点击按钮没有反应

<?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"
    tools:context="com.hala.view01.Main2Activity">

<RelativeLayout
    android:id="@+id/rl"
    android:layout_width="368dp"
    android:layout_height="439dp"
    android:layout_marginLeft="8dp"
    app:layout_constraintLeft_toLeftOf="parent"
    android:layout_marginRight="8dp"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:layout_marginTop="8dp"
    android:layout_marginBottom="8dp"
    app:layout_constraintBottom_toTopOf="@+id/button">

    <ImageView
        android:id="@+id/iv"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:src="@drawable/timg"
        android:visibility="gone"/>
</RelativeLayout>

    <Button
        android:onClick="onClick"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="8dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="0dp"
        android:text="开始"
        android:id="@+id/button"
        app:layout_constraintHorizontal_weight="1"
        android:layout_marginStart="8dp" />

    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="分数"
        android:textSize="25sp"
        android:gravity="center"
        app:layout_constraintLeft_toRightOf="@+id/tv"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp"
        app:layout_constraintTop_toTopOf="@+id/button"
        android:layout_marginTop="8dp"
        android:layout_marginRight="8dp"
        app:layout_constraintVertical_bias="0.521"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintHorizontal_weight="1"
        android:layout_marginEnd="8dp" />


</android.support.constraint.ConstraintLayout>

java文件

package com.hala.view01;

import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import java.lang.ref.WeakReference;
import java.util.Random;

public class Main2Activity extends AppCompatActivity implements View.OnClickListener,View.OnTouchListener {


    public static final int Code = 123;
    public static final int Rand = 500;
    public static final int MAX = 10;
    private TextView tv;
    private Button bt;
    private ImageView iv;
    private RelativeLayout rl;


    private int total;
    private int success;

    private DiglettHandler diglettHandler=new DiglettHandler(this);


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        initView();
    }

    private void initView() {
        tv = (TextView)findViewById(R.id.tv);
        bt = (Button)findViewById(R.id.button);
        iv = (ImageView)findViewById(R.id.iv);
        rl = (RelativeLayout)findViewById(R.id.rl);
        bt.setOnClickListener(this);
        iv.setOnTouchListener(this);

        //此句容易漏掉
        DiglettHandler diglettHandler=new DiglettHandler(this);

    }


    /**
     * 点击按钮开始游戏
     * @param v
     */
    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.bt:
                start();
                break;
        }
    }

    /**
     * 开始打第一个地鼠
     * 发送消息
     */
    private void start() {

        total=0;
        success=0;
        bt.setText("游戏中。。。");
        bt.setEnabled(false);

        next(0);
    }

    /**
     * 打第一个以后的地鼠
     * @param delayTime
     */
    private void next(int delayTime){
        //Random().nextInt(368)表示生成0～368的随机数，包括0，不包括368
        int x=new Random().nextInt(368);
        int y=new Random().nextInt(439);

        Message message=Message.obtain();
        message.what= Code;
        message.arg1=x;
        message.arg2=y;

        diglettHandler.sendMessageDelayed(message,delayTime);
        total++;
    }

    /**
     * 游戏结束的反应
     */
    private void clear(){
        total=0;
        success=0;
        iv.setVisibility(View.GONE);
        bt.setText("开始");
        bt.setEnabled(true);

    }

    /**
     * 打中地鼠后的反应
     * @param v
     * @param event
     * @return
     */
    @Override
    public boolean onTouch(View v, MotionEvent event) {

        //地鼠为不可见
        v.setVisibility(View.GONE);
        success++;
        tv.setText("打到"+success+"只，漏掉"+(total-success)+"只哦");
        return false;
    }

    public static class DiglettHandler extends Handler{

        public final WeakReference<Main2Activity> mWeaker;

        public DiglettHandler(Main2Activity activity) {
            mWeaker=new WeakReference<Main2Activity>(activity);

        }


        /**
         * 点击屏幕后的处理机制
         * @param msg
         */
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            Main2Activity activity=mWeaker.get();

            switch (msg.what){
                case Code:
                    if(activity.total> MAX){
                        activity.clear();
                        activity.tv.setText("^ _ ^ 结束了，下次再来 ^ _ ^");
                        return;
                    }
                    int x=msg.arg1;
                    int y=msg.arg2;
                    activity.iv.setX(x);
                    activity.iv.setY(y);
                    //默认为不显示，这里要显示出来
                    activity.iv.setVisibility(View.VISIBLE);

                    //传回随机时间，执行next方法
                    int randomTime=new Random().nextInt(Rand)+ Rand;
                    activity.next(randomTime);
                    break;
            }
        }
    }
}

配置文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.hala.view01">

    <!-- 网络链接，写文件和读文件的权限 -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/title1"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity"></activity>
        <activity android:name=".Main2Activity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

程序运行后显示了开始界面但点击开始按钮并没有反应