问题
我要走了 java.lang.IllegalStateException: Could not find method secondOne(View) in a parent or ancestor Context for android:onClick attribute defined on view class androidx.appcompat.widget.AppCompatButton 我做了什么？
在清单中，我有以下活动：

<activity
        android:name=".MainActivity"
        android:label="@string/app_name">
    </activity>

    <activity
        android:name=".LeadActivity"
        android:label="@string/app_name">
    </activity>

    <activity
        android:name=".MainMenu"
        android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

在game_menu.xml中，我有两个按钮。第一个有 android:onClick="firstOne" 财产，第二有 android:onClick="secondOne" 财产。
在 class MainMenu ，其中 extends AppCompatActivity 我有两种方法：

public void firstOne(View view) {
    Intent intent = new Intent(MainMenu.this, MainActivity.class);
    startActivity(intent);
}

public void secondOne(View view) {
    Intent intent = new Intent(MainMenu.this, LeadActivity.class);
    startActivity(intent);
}

当我点击第一个按钮时，mainactivity.class会正常运行。
但是当我点击第二个按钮时，这个错误就出现了。 java.lang.IllegalStateException: Could not find method secondOne(View) in a parent or ancestor Context for android:onClick attribute defined on view class androidx.appcompat.widget.AppCompatButton 拜托，救命啊。我做错什么了？
升级版
完整的主菜单类代码：

public class MainMenu extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.game_menu);

    //Hide the status bar and the action bar
    View decorView = getWindow().getDecorView();
    int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
    decorView.setSystemUiVisibility(uiOptions);
    ActionBar actionBar = getSupportActionBar();
    actionBar.hide();
}

public void firstOne(View view) {
    Intent intent = new Intent(MainMenu.this, MainActivity.class);
    startActivity(intent);
}

public void secondOne(View view) {
    Intent intent = new Intent(MainMenu.this, LeadActivity.class);
    startActivity(intent);
}}

升级2
游戏菜单.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="centerCrop"
        android:src="@drawable/sky"
        tools:layout_editor_absoluteX="0dp"
        tools:layout_editor_absoluteY="-16dp" />

    <Button
        android:id="@+id/button_start"
        android:layout_width="175dp"
        android:layout_height="76dp"
        android:layout_marginTop="200dp"
        android:background="@color/black"
        android:onClick="firstOne"
        android:text="@string/playButtonText"
        android:textColor="@color/white"
        android:textSize="40sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toStartOf="@+id/imageView"
        app:layout_constraintStart_toEndOf="@+id/imageView"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button_lead"
        android:layout_width="175dp"
        android:layout_height="76dp"
        android:layout_marginTop="312dp"
        android:background="@color/black"
        android:onClick="secondOne"
        android:text="@string/leaderboardButtonText"
        android:textColor="@color/white"
        android:textSize="30sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toStartOf="@+id/imageView"
        app:layout_constraintStart_toEndOf="@+id/imageView"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>