7、窗口导航

 回到主窗口

1. 将主窗口的创建模式设为singleTask。
2. 直接显示主窗口 

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setTitle("主窗口:" + String.valueOf(hashCode()));
    }

    public void onClick_NewActivity(View view) {
        Intent intent = new Intent(this, NewActivity.class);
        startActivity(intent);
    }

}

public class NewActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_new);
        setTitle("新窗口:" + String.valueOf(hashCode()));
    }

    public void onClick_NewActivity(View view) {
        Intent intent = new Intent(this, NewActivity.class);
        startActivity(intent);
    }

    public void onClick_GoMainActivity(View view) {
        Intent intent = new Intent(this, MainActivity.class);
        startActivity(intent);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="cn"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="17"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="cn.MainActivity"
            android:label="@string/app_name"
            android:launchMode="singleTask" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
        <activity android:name="cn.NewActivity" />
    </application>

</manifest>

 滑动导航

涉及到的主要Java类。

ViewPager       FragmentPagerAdapter 

import java.util.Locale;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MainActivity extends FragmentActivity {

    /**  
     * The {@link android.support.v4.view.PagerAdapter} that will provide
     * fragments for each of the sections. We use a
     * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
     * will keep every loaded fragment in memory. If this becomes too memory
     * intensive, it may be best to switch to a
     * {@link android.support.v4.app.FragmentStatePagerAdapter}.
     */
    SectionsPagerAdapter mSectionsPagerAdapter;

    /**
     * The {@link ViewPager} that will host the section contents.
     */
    ViewPager mViewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Create the adapter that will return a fragment for each of the three
        // primary sections of the app.
        mSectionsPagerAdapter = new SectionsPagerAdapter(
                getSupportFragmentManager());
        

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    /**
     * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
     * one of the sections/tabs/pages.
     */
    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            // Return a DummySectionFragment (defined as a static inner class
            // below) with the page number as its lone argument.
            Fragment fragment = new DummySectionFragment();
            Bundle args = new Bundle();
            args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
            fragment.setArguments(args);
            return fragment;
        }

        @Override
        public int getCount() {
            // Show 3 total pages.
            return 3;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();
            switch (position) {
            case 0:
                return getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return getString(R.string.title_section2).toUpperCase(l);
            case 2:
                return getString(R.string.title_section3).toUpperCase(l);
            }
            return null;
        }
    }

    /**
     * A dummy fragment representing a section of the app, but that simply
     * displays dummy text.
     */
    public static class DummySectionFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        public static final String ARG_SECTION_NUMBER = "section_number";

        public DummySectionFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main_dummy,
                    container, false);
            
            TextView dummyTextView = (TextView) rootView
                    .findViewById(R.id.section_label);
            dummyTextView.setText(Integer.toString(getArguments().getInt(
                    ARG_SECTION_NUMBER)));
            return rootView;
        }
    }

}

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <!--
         This title strip will display the currently visible page title, as well as the page
         titles for adjacent pages.
    
         R.layout.activity_main
    -->

    <android.support.v4.view.PagerTitleStrip
        android:id="@+id/pager_title_strip"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="top"
        android:background="#33b5e5"
        android:paddingBottom="4dp"
        android:paddingTop="4dp"
        android:textColor="#fff" />

</android.support.v4.view.ViewPager>

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <!--
         R.menu.main
    -->
    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="@string/action_settings"/>
</menu>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">MultiPageNavigation</string>
    <string name="action_settings">Settings</string>
    <string name="title_section1">Section 1</string>
    <string name="title_section2">Section 2</string>
    <string name="title_section3">Section 3</string>
</resources>

<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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity$DummySectionFragment" >
<!-- 
     R.layout.fragment_main_dummy
 -->
    <TextView
        android:id="@+id/section_label"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>

 Fragment导航 

使用的主要技术:Fragment Backstack。

FragmentTransaction.addToBackStack

FragmentManager.popBackStack(); 

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentManager.OnBackStackChangedListener;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;

public class FragmentNavigationActivity extends Activity implements
        OnBackStackChangedListener {

    private void nextFragment(boolean backStackFlag) {
        try {
            FragmentManager fragmentManager = getFragmentManager();

            FragmentTransaction fragmentTransaction = fragmentManager
                    .beginTransaction();
            FragmentPage fragment = new FragmentPage();
            fragmentTransaction.add(R.id.fragment_container, fragment);

            if (backStackFlag)
                fragmentTransaction
                        .addToBackStack(String.valueOf(getFragmentManager()
                                .getBackStackEntryCount() + 1));
            fragmentTransaction.commit();
            fragmentManager.addOnBackStackChangedListener(this);

        } catch (Exception e) {  }
    }

    @Override
    public void onBackStackChanged() {
        setTitle("当前第" + (getFragmentManager().getBackStackEntryCount() + 1)
                + "页");
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fragment_navigation);
        nextFragment(false);
        onBackStackChanged();
    }

    public void onClick_NextPage(View view) {
        nextFragment(true);
    }

    public void onClick_PrevPage(View view) {
        FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.popBackStack();
        // 将回退栈在Fragment状态全部出栈，恢复到第1页
        // fragmentManager.popBackStackImmediate("1",FragmentManager.POP_BACK_STACK_INCLUSIVE);
    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
<!-- 
     R.layout.activity_fragment_navigation
 -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
        <Button
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"
            android:onClick="onClick_PrevPage"
            android:text="上一页" android:layout_weight="1" />
        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:onClick="onClick_NextPage"
            android:text="下一页" android:layout_weight="1" />
    </LinearLayout>

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

</LinearLayout>

import java.util.Random;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;

public class FragmentPage extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_page, container, false);

        EditText editText = (EditText) view.findViewById(R.id.edittext);

        editText.setText(String.valueOf(Math.abs(new Random().nextLong())));
        return view;
    }

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" android:background="#FFF">
<!-- 
     R.layout.fragment_page
 -->
    <EditText
        android:id="@+id/edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="第一页" />

</LinearLayout>