问用静态片段替换活动内容

EN

package com.example.wbslideshow;

public class MainActivity extends Activity implements MainFrag.onstartFragBtnClickListener {
    public static final String KEYVAL = "startpath"; 

    Bundle mySavedInstanceState;
    MainFrag newMainFrag;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mySavedInstanceState = savedInstanceState;

        //initialize the preferences from the xml-file 
        //if app is running the first time this will be taken from the xml-file
        PreferenceManager.setDefaultValues(this, R.xml.preferences, false);

        //load the MainFrag to select a path to the images and start-button
        newMainFrag = new MainFrag();
        FragmentTransaction transaction = getFragmentManager().beginTransaction();
        transaction.add(R.id.mycontainer, newMainFrag);
        transaction.addToBackStack(null);
        transaction.commit(); 

    }

    //procedure from the interface of the MainFrag class to look for images in the given path
    @Override
    public void onstartFragBtnClicked(String root) 
    {
        //call procedure "private boolean LandscapeMode()" to check the mode
        if (!LandscapeMode())
        {
            ListFrag newListFrag = new ListFrag();
            //put the value from the EditText field of MainFrag class into the arguments for the ListFrag class
            Bundle args = new Bundle();
            args.putString(ListFrag.FRAG_MESSAGE_DEF_Input, root);
            newListFrag.setArguments(args);

            //change the fragments dynamically
            FragmentTransaction transaction = getFragmentManager().beginTransaction();
            transaction.replace(R.id.mycontainer, newListFrag);
            transaction.addToBackStack(null);
            transaction.commit(); 
        }
        else
        {
            //remove the MainFrag
            FragmentTransaction transaction = getFragmentManager().beginTransaction();
            transaction.remove(newMainFrag);
            transaction.commit(); 

            //load the static ListFrag 
            ListFrag newListFrag = new ListFrag();
            //put the value from the EditText field of MainFrag class into the arguments for the ListFrag class
            Bundle args = new Bundle();
            args.putString(ListFrag.FRAG_MESSAGE_DEF_Input, root);

            //load the ImgFrag for the right pane into the FrameLayout 
            ImgFrag myImgFrag = new ImgFrag();
            if (myImgFrag != null) 
            {
                transaction = getFragmentManager().beginTransaction();
                transaction.add(R.id.myImgContainer, myImgFrag);
                transaction.commit();
            }
        }
    }

    private boolean LandscapeMode() { 
         if (getResources().getConfiguration().orientation ==  
                   Configuration.ORIENTATION_PORTRAIT) {
             return false;
             }

         else 
             if (getResources().getConfiguration().orientation ==  
               Configuration.ORIENTATION_LANDSCAPE) {
                 return true;
         } else return false;
    } 


}

public class MainFrag extends Fragment implements OnClickListener{ //, OnSharedPreferenceChangeListener {

    /*
     * Constant is representing the value of the android:key from preferences.xml. 
     * This value is found in android:defaultValue
    */
    public static final String KEYVAL = "startpath"; 
    public static final String JPGVAL = "pref-jpg";
    public static final String PNGVAL = "pref-png";

    EditText myEditText;
    SharedPreferences sharedPref;

    //define the interface to communicate with the main activity when user clicked the button
    private onstartFragBtnClickListener mCallback;
    public interface onstartFragBtnClickListener {
        public void onstartFragBtnClicked(String myInput);
    }

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle SavedInstanceState ) {
        View view = inflater.inflate(R.layout.main_frag, container, false);

        //instantiate the start button and register the onClickListener
        Button start = (Button) view.findViewById(R.id.startBtn);
        start.setOnClickListener(this);

        //read the current path to the pics from SharedPreferences file
        Activity myActivity = getActivity();
        sharedPref = PreferenceManager.getDefaultSharedPreferences(myActivity.getBaseContext());

        //registerPreferenceListener();
        myEditText = (EditText) view.findViewById(R.id.inputSearchPath);
        myEditText.setText(sharedPref.getString(KEYVAL, "/"));
        return view;
    }

    @Override
    public void onResume() {
        super.onResume();
        //read the current path to the pics from SharedPreferences file
        Activity myActivity = getActivity();
        sharedPref = PreferenceManager.getDefaultSharedPreferences(myActivity.getBaseContext());
        myEditText.setText(sharedPref.getString(KEYVAL, "/"));
    }

    @Override
    public void onAttach (Activity activity) {
        super.onAttach(activity);
        try
        {mCallback = (onstartFragBtnClickListener) activity;}
        catch (ClassCastException e) 
        {throw new ClassCastException(activity.toString()
                  + " must implement OnControlButtonClickedListener");}
    }


    //change to ListFrag class if user clicked the button
    @Override
    public void onClick(View view) 
    {
        Activity myActivity = getActivity();
        if (myActivity != null) 
        {
            //Get the users input for to pass it to the activity
            String root = ((EditText) myActivity.findViewById(
                    R.id.inputSearchPath)).getText().toString();

            //Call the interface method in the activity to go on
            mCallback.onstartFragBtnClicked(root);
        }
    }

}

package com.example.wbslideshow;
public class ListFrag extends ListFragment{

    ImageView image;
    //Arrays to get files and folders 
    private List<String> listItem = null;
    //TextView  Object for the headline 
    private TextView TVmyPath;
    //global variable taken the start path once 
    //used to compare when user clicked an item
    private String g_startPath, g_myInput;

    /* define a constant to take the passed input string from the start fragment */
    public static String FRAG_MESSAGE_DEF_Input = "com.example.wbslideshow.CALL_ListFragment"; 

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle SavedInstanceState ) {
        View  myview = inflater.inflate(R.layout.list_frag, container, false);
        TVmyPath = (TextView) myview.findViewById(R.id.startpath);
        return myview;
    } 

    @Override
    public void onStart() 
    {
        super.onStart();
        Activity myActivity = getActivity();

        //get an instance of the image and make it invisible 
        image = (ImageView) myActivity.findViewById(R.id.imageView1);
        image.setVisibility(View.INVISIBLE);

         Bundle args = getArguments();
         if (args != null) { g_startPath = args.getString(FRAG_MESSAGE_DEF_Input); } 

         //save the input the very first time to compare later with new item click
         g_myInput = g_startPath;

         getDir(g_startPath);  
    }   

    private void getDir(String p_startPath)
    {
        //set the headline
        TVmyPath.setText("Location: " + p_startPath);

        listItem = new ArrayList<String>();

        File f = new File(p_startPath);
        //file array which get's all the folders and files from the input path
        File[] files = f.listFiles();

        //startPath changed if user clicked a new folder 
        if(!g_myInput.equals(p_startPath))
        {
            //alter g_myInput for the next comparison
            g_myInput = p_startPath;
            //put this item to make it possible to get one directory up
            listItem.add("../");
        }

        Arrays.sort(files, filecomparator);

        for(int i=0; i < files.length; i++)
        {
            if(files[i].isFile())
            {
                String filename = files[i].getName();
                //get the file extension 
                int z = filename.lastIndexOf('.');
                //read the file extension
                String wbname = filename.substring(z+1);
                if (wbname.equalsIgnoreCase("jpg"))  {listItem.add(filename);}
                if (wbname.equalsIgnoreCase("jpeg")) {listItem.add(filename);}
            }
            else {listItem.add(files[i].getName() + "/");}
        }
        ArrayAdapter<String> fileList =
                new ArrayAdapter<String>(getActivity(), R.layout.row, listItem);
        Activity myActivity = getActivity();
        ListView myList = (ListView) myActivity.findViewById(android.R.id.list);
        myList.setAdapter(fileList); 
    }

    //procedure to sort the arrays
    Comparator<? super File> filecomparator = new Comparator<File>(){

        public int compare(File file1, File file2) {
            if(file1.isDirectory()){
                if (file2.isDirectory()){
                    return String.valueOf
                            (file1.getName().toLowerCase(Locale.getDefault())).compareTo
                            (file2.getName().toLowerCase(Locale.getDefault()));
                }else{
                    return -1;
                }
            }else {
                if (file2.isDirectory()){
                    return 1;
                }else{
                    return String.valueOf
                            (file1.getName().toLowerCase(Locale.getDefault())).compareTo
                            (file2.getName().toLowerCase(Locale.getDefault()));
                }
            }
        }   
    };


    @Override
    public void onListItemClick(ListView l, View v, int position, long id) 
    {
        File file;
        //user clicked one path back
        if (listItem.get(position) == "../") 
            {
                file = new File(g_startPath);
                g_startPath = file.getParent();
            }
        else 
        //if user clicked to a picture or 
        //to a new folder (>> getDir has to be called with the new path)
        //      >>file has to be set to path and position   
        {file = new File(g_startPath + '/' + listItem.get(position));}

            Bitmap myBitmap;
            //user clicked only to an image >> the image has to be shown in the image view - nothing else
            if (file.isFile())
            {
                //if(file.canRead()){
                myBitmap = BitmapFactory.decodeFile(file.getPath());
                image.setImageBitmap(myBitmap);
                image.setVisibility(View.VISIBLE);
                //}
            }else   
            {
                if (file.isDirectory())
                {
                        image.setVisibility(View.INVISIBLE);
                        if (listItem.get(position) != "../"){g_startPath = file.getPath();}
                        getDir(g_startPath);
                }
            }   
    }
} 

package com.example.wbslideshow;

public class ImgFrag extends Fragment{
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        View myImgView = inflater.inflate(R.layout.img_frag, container, false);
        return myImgView;
    }

}

<LinearLayout 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:background="#DA8306"
    android:orientation="vertical" 
    android:id="@+id/mycontainer">

</LinearLayout

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

    <TextView
        android:id="@+id/startHeader"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/startHeader" />

    <EditText
        android:id="@+id/inputSearchPath"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="@string/startInputHint" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/startBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/startBtn" />

</LinearLayout>

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

    <TextView
        android:id="@+id/startpath"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#C27302"
        android:height="40dp"
        android:maxLines="1"
        android:scrollHorizontally="false"
        android:text="@string/list_header"
        android:textSize="16sp"
        android:textStyle="bold" />

    <ListView
        android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="312dp"
        android:layout_gravity="fill"
        android:background="#B012EB" />

    <TextView
        android:id="@+id/empty"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/abc_ab_bottom_solid_dark_holo" />

        <FrameLayout
        android:id="@+id/myImgContainer"
        android:layout_weight="2"
        android:layout_width="0dp"
        android:layout_height="fill_parent"
         />

</LinearLayout>

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

    <!-- static fragment for the left pane -->
    <fragment
        android:name="com.example.wbslideshow.ListFrag"
        android:id="@+id/listFrag"
        android:layout_width="0dp"
        android:layout_height="fill_parent"
        android:layout_weight="1" />

    <FrameLayout
        android:id="@+id/myImgContainer"
        android:layout_weight="2"
        android:layout_width="0dp"
        android:layout_height="fill_parent">
    </FrameLayout>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" 
    android:id="@+id/imgFrag">

        <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/abc_ab_bottom_solid_dark_holo" />


</LinearLayout>