点击main activity中的按钮，需要启用fragment的按钮

<Button
    android:id="@+id/fragmentButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="启用Fragment" />

Button fragmentButton = findViewById(R.id.fragmentButton);
fragmentButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        // 在点击事件中启用fragment
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        
        // 创建并添加需要启用的fragment
        MyFragment myFragment = new MyFragment();
        fragmentTransaction.add(R.id.fragmentContainer, myFragment);
        
        // 提交事务
        fragmentTransaction.commit();
    }
});

<FrameLayout
    android:id="@+id/fragmentContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />