求助帖
android 在activity中设置一个按钮，监听点击跳转fragment，但是没想到跳转后两个页面内容同时展示了，大佬们这个问题我该怎么解决呢！！

@Override

    public void onClick(View v) {

        androidx.fragment.app.FragmentManager fragmentManager = getSupportFragmentManager();

        androidx.fragment.app.FragmentTransaction beginTransaction = fragmentManager.beginTransaction();

        switch (v.getId()) {

            case R.id.frg1:

                Log.d(TAG, "点击跳转事件");

                beginTransaction.replace(R.id.main_re, new BlankFragment());

                beginTransaction.addToBackStack(null);

                break;

        }

        beginTransaction.commit();

        //        moveTaskToBack(true);

    }

这是MainActivity布局

<?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"

    tools:context=".MainActivity">



    <FrameLayout

        android:id="@+id/main_re"

        android:layout_width="match_parent"

        android:layout_height="match_parent">

        

        <Button

            android:id="@+id/frg1"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:autoLink="all"

            android:text="跳转"

            tools:ignore="MissingConstraints"

            tools:layout_editor_absoluteX="248dp"

            tools:layout_editor_absoluteY="295dp" />



    </FrameLayout>



</androidx.constraintlayout.widget.ConstraintLayout>

这是运行结果