启动另一项活动后，onclick无法正常工作

Question

当我从MainActivity意图注册Register类中的按钮侦听器时，我有两个活动 MainActivity 和注册。

这是代码

MainActivity

public class MainActivity extends AppCompatActivity {


    // defining all the components
    AlertDialog builder;
    public EditText Email,Password;
    public ImageButton fb,twitter;
    public Button register;
    public String email;
    public String password;
    public BackgroungWorker backgroungWorker;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        builder = new AlertDialog.Builder(this).create();
        setContentView(R.layout.activity_main);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        getSupportActionBar().hide();
        Email= (EditText) findViewById(R.id.email);
        Password= (EditText) findViewById(R.id.pass);
        fb= (ImageButton) findViewById(R.id.fb_button);
        twitter= (ImageButton) findViewById(R.id.tw_button);
        register = (Button) findViewById(R.id.register);
    }


    // for listening to the events

    public void eventHappend(View view)
    {
        if(view.getId()==R.id.login)
        {

            email = Email.getText().toString();
            password = Password.getText().toString();
            if(email.equals(""))
            {
                showMessage("Error","Email cannot be blank");
                return;
            }
            if(password.equals(""))
            {
                showMessage("Error","Enter your password");
                return;
            }
            backgroungWorker = new BackgroungWorker(this);
            backgroungWorker.execute("Login",email,password);

        }

        if(view.getId()==R.id.register)
        {
            // INTENT TO REGISTER ACTIVITY
            Intent intent = new Intent(MainActivity.this,Register.class);
            startActivity(intent);
        }

        if(view.getId()==R.id.forgot)
        {


        }

        if(view.getId()== R.id.fb_button)
        {
            showToast("Facebook!!");
        }
        if(view.getId()==R.id.tw_button)
        {
            showToast("Twitter");
        }
    }

    public void showToast(String s)
    {
        Toast toast = new Toast(this);
        toast.makeText(this,s, Toast.LENGTH_SHORT).show();
    }

    public void showMessage(String title,String message)
    {
        builder.setTitle(title);
        builder.setMessage(message);
        builder.setCancelable(true);
        builder.show();
    }}

注册

public class Register extends Activity {

    String user_name,pass,confim_password,email;
    AlertDialog builder;
    private EditText name,mail,password,confirm_pass;
    private Button register;
    private BackgroungWorker backgroungWorker;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.register);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
        mail = (EditText) findViewById(R.id.email);
        name = (EditText) findViewById(R.id.name);
        password = (EditText) findViewById(R.id.pass);
        confirm_pass= (EditText) findViewById(R.id.confirmpass);
        register = (Button) findViewById(R.id.register_btn);
        builder = new AlertDialog.Builder(this).create();
    }


    public void registerClicked(View view) // this is not working
    {
        if(view.getId()==R.id.register_btn)
        {
            if(name.getText().equals(""))
            {
                showMessage("Error","Name Cannot be left blank");
                return;
            }

            if(mail.getText().equals(""))
            {
                showMessage("Error","Email Cannot be left blank");
                return;
            }

            if(password.getText().equals(""))
            {
                showMessage("Error","Password Cannot be left blank");
                return;
            }

            if(password.getText().equals(confirm_pass.getText().toString()))
            {
                backgroungWorker = new BackgroungWorker(this);
                backgroungWorker.execute("Register",name.getText().toString(),password.getText().toString(),mail.getText().toString());
            }
        }
    }


    public void showMessage(String title,String message)
    {
        builder.setTitle(title);
        builder.setMessage(message);
        builder.setCancelable(true);
        builder.show();
    }}

register.xml

`<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    android:background=
    android:backgroundTint="#02b864">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:background="#02b864">

        <ImageView
            android:layout_width="212dp"
            android:layout_height="176dp"
            android:id="@+id/imageView"
            android:layout_gravity="center_horizontal"
            android:background="@drawable/splash"
            android:layout_marginTop="20dp"/>



        <LinearLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="20dp">

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="50dp"
                android:hint="Name"
                android:id="@+id/name"
                android:drawableLeft="@drawable/ic_username"
                android:drawableTint="@color/colorPrimaryDark"
                android:drawablePadding="@dimen/activity_vertical_margin"
                android:focusable="true"
                android:background="@drawable/editext_bg_gray"
                android:layout_gravity="center_horizontal"
                android:layout_marginLeft="25dp"
                android:layout_marginRight="25dp"
                android:singleLine="true"
                android:layout_marginTop="20dp" />

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="50dp"
                android:hint="Email"
                android:id="@+id/email"
                android:drawableLeft="@drawable/ic_username"
                android:drawableTint="@color/colorPrimaryDark"
                android:drawablePadding="@dimen/activity_vertical_margin"
                android:focusable="true"
                android:background="@drawable/editext_bg_gray"
                android:layout_gravity="center_horizontal"
                android:layout_marginLeft="25dp"
                android:layout_marginRight="25dp"
                android:singleLine="true"
                android:layout_marginTop="5dp"
                />

            <EditText
                android:inputType="textPassword"
                android:ems="10"
                android:id="@+id/pass"
                android:layout_width="wrap_content"
                android:layout_height="50dp"
                android:hint="Password"
                android:drawableLeft="@drawable/ic_pwd"
                android:drawablePadding="@dimen/activity_horizontal_margin"
                android:drawableTint="@color/colorPrimaryDark"
                android:focusable="true"
                android:background="@drawable/editext_bg_gray"
                android:layout_gravity="center_horizontal"
                android:layout_marginRight="25dp"
                android:layout_marginLeft="25dp"
                android:layout_marginTop="5dp"
                android:singleLine="true" />

            <EditText
                android:inputType="textPassword"
                android:ems="10"
                android:id="@+id/confirmpass"
                android:layout_width="wrap_content"
                android:layout_height="50dp"
                android:hint="Confirm Password"
                android:drawableLeft="@drawable/ic_pwd"
                android:drawablePadding="@dimen/activity_horizontal_margin"
                android:drawableTint="@color/colorPrimaryDark"
                android:focusable="true"
                android:background="@drawable/editext_bg_gray"
                android:layout_gravity="center_horizontal"
                android:layout_marginRight="25dp"
                android:layout_marginLeft="25dp"
                android:layout_marginTop="5dp"
                android:singleLine="true" />

            <Button
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/register_btn"
                android:onClick="registerClicked"
                android:clickable="true"
                android:layout_gravity="center_horizontal"
                android:background="#e5e7e8"
                android:text="Register"
                android:src="@drawable/editext_bg_gray"
                android:textColor="#0fbb6c"
                android:singleLine="true"
                android:layout_marginLeft="25dp"
                android:layout_marginRight="25dp"
                android:layout_marginTop="50dp"
                android:textStyle="normal"
                android:textAlignment="center"
                android:textSize="22dp"
                />
            android:layout_gravity="center_horizontal" />
        </LinearLayout>

    </LinearLayout>

</RelativeLayout>`

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.umarsafdar.dev96.chat">
<uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

        <activity android:name=".Splash"
            android:screenOrientation="portrait">

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />

        </intent-filter>

        </activity>

        <activity android:name=".Register"
        android:screenOrientation="portrait">
            <intent-filter>

                <action android:name="android.intent.action.MAIN">

                    <category android:name="android.intent.category.DEFAULT" />


                </action>
            </intent-filter>
        </activity>
    </application>

</manifest>

提前感谢。