无法从主要活动加载片段

Question

I am trying to load a frame on the Onclicklistener of a Button in the main activity. In my view I have written all the code correctly of main activity and fragment that requires to attach a fragment to activity. But something seems off. Appreciate any thoughts or suggestions. I have used this link as a reference. Below are the code details.

MainActivity.java

    import android.annotation.TargetApi;
    import android.os.Build;
    import android.os.Bundle;
    import android.support.v4.app.FragmentActivity;
    import android.support.v4.app.FragmentManager;
    import android.support.v4.app.FragmentTransaction;
    import android.support.v7.app.ActionBar;
    import android.view.Menu;
    import android.view.MenuInflater;
     import android.view.MenuItem;
    import android.view.View;
     import android.view.View.OnClickListener;
    import android.widget.Button;

 public class MainActivity extends FragmentActivity {


@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final android.app.ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);


    Button btnLoad = (Button) findViewById(R.id.Button01);

    OnClickListener listener = new OnClickListener() {

        @Override
        public void onClick(View v) {
       FragmentManager fragmentManager = getSupportFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

            AboutFragment mAboutFragment = new AboutFragment();
            fragmentTransaction.add(R.id.fragment_container, mAboutFragment,"About");
            fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            fragmentTransaction.commit();
       }
    };

    btnLoad.setOnClickListener(listener);

 }


}

activity_main.xml

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

  <RelativeLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <Button
        android:id="@+id/Button01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/title_about"
        android:minHeight="92dp"
        android:layout_marginTop="40dp"
        android:layout_marginLeft="40dp"
        android:textSize="22sp"></Button>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/title_report"
        android:id="@+id/Button02"        
        android:minHeight="92dp"
        android:textSize="22sp"
        android:layout_marginTop="40dp"
        android:layout_marginLeft="80dp"
        android:layout_toRightOf="@+id/Button01"></Button>
  </RelativeLayout>
        <FrameLayout
                android:id="@+id/fragment_container"
                android:layout_width="match_parent"
                android:layout_height="match_parent" >

        </FrameLayout>

</LinearLayout>

AboutFragement.jave

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

public class AboutFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
        // Inflate the layout for this fragment
          View view = inflater.inflate(R.layout.about_fragment_main, container, false);

          return view;
    }

}

about_fragement_main.xml

LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:orientation="vertical" >

            <TextView android:id="@+id/about_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:layout_gravity="center"
        android:paddingTop="30px"
        android:text="header text"
        android:textStyle="bold|italic"/>

          <TextView
            android:id="@+id/text1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:text="text here" />

       <TextView android:id="@+id/about_textview2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:layout_gravity="center"
        android:text="zariya mission"
        android:textStyle="bold|italic"/>

          <TextView
            android:id="@+id/text2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:paddingTop="10px"
            android:text="text here" />


          <TextView android:id="@+id/about_textview3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:layout_gravity="center"
        android:text="zariya vision"
        android:textStyle="bold|italic"/>

          <TextView
            android:id="@+id/text3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:paddingTop="10px"
            android:text="text here" />

          <TextView android:id="@+id/about_textview4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:layout_gravity="center"
        android:text="zariya values"
        android:textStyle="bold|italic"/>

          <TextView
            android:id="@+id/text4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:paddingTop="10px"
            android:text="sometezt." />

 </LinearLayout>

Answer 1

The error is in the main XML file.

You root is

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">

But then the first child have the height fill_parent this makes the first child take all the space of the LinearLayout so when you try to put your fragment in the container, it wont appear in the screen.

Instead try this

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    ....

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

Try to get used to use match_parent instead of fill_parent :)