为什么我的碎片＆＃39; UI没有切换？ （包括带代码的github repo）

Question

我正在尝试处理Android视图及其切换。看来这应该很简单，但是......

我正在使用ADK。我创建了一个项目，ViewsToAKill，带有片段的空白活动＆＃39;。我把名字保留为默认名称。然后我添加了一个名为＆＃34; NextActivity＆＃34;。

的新片段活动

我没有触及Activity java类。其余的在下面。问题是这个。当我点击Go按钮时，我希望＆＃34;再见！＆＃34;取代＆＃34;你好！＆＃34;。相反，我看到＆＃34;你好！＆＃34;和Go按钮，我也看到了＃34; Goodbye！＆＃34;部分隐藏在按钮下方。为什么呢？

$ cat app/src/main/res/layout/activity_main.xml
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/fragment"
    android:name="com.rrk.viewstoakill.MainActivityFragment"
    tools:layout="@layout/fragment_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

</fragment>
$ 
$ cat app/src/main/res/layout/fragment_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivityFragment">

    <TextView
        android:id="@+id/hello_view"
        android:text="Hello!"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/button_go"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/hello_view"
        android:text="Go!"
        android:clickable="true"
        />

</RelativeLayout>
$ 
$ cat app/src/main/res/layout/activity_next.xml
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/fragment"
    android:name="com.rrk.viewstoakill.NextActivityFragment"
    tools:layout="@layout/fragment_next"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />
$ 
$ 
$ cat app/src/main/res/layout/fragment_next.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="com.rrk.viewstoakill.NextActivityFragment">

    <TextView
        android:text="Goodbye!"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>
$ 
$ cat app/src/main/java/com/rrk/viewstoakill/MainActivityFragment.java
package com.rrk.viewstoakill;

import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;


/**
 * A placeholder fragment containing a simple view.
 */
public class MainActivityFragment extends Fragment {

    public MainActivityFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        TextView button = (Button)rootView.findViewById(R.id.button_go);

        button.setOnClickListener(new Button.OnClickListener() {

            public void onClick(View v) {

                Fragment nextFragment = new NextActivityFragment();
                FragmentTransaction transaction = getFragmentManager().beginTransaction();

                transaction.replace(R.id.fragment_container, nextFragment);
                transaction.addToBackStack(null);

                transaction.commit();
            }
        });

        return rootView;
    }
}
$ 
$ cat app/src/main/java/com/rrk/viewstoakill/NextActivityFragment.java

package com.rrk.viewstoakill;

import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


/**
 * A placeholder fragment containing a simple view.
 */
public class NextActivityFragment extends Fragment {

    public NextActivityFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_next, container, false);
    }
}

$

Answer 1

基本上去

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/fragment_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

  <fragment
        android:id="@+id/fragment"
        android:name="com.rrk.viewstoakill.MainActivityFragment"
        tools:layout="@layout/fragment_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

activity_main.xml

中的

Answer 2

您是否在片段的xml布局文件中设置了background属性？

android:background="?android:windowBackground"