使用ViewPager和Fragments

Question

我是初学者Android开发人员.我试图绕过ViewPager.在我尝试使用此示例之前:

http://mobile.tutsplus.com/tutorials/android/android-user-interface-design-horizo​​ntal-view-paging/

我的视图有效,但无法在其中运行功能,我被告知我需要在ViewPager中使用Fragments.

我选择了这个教程:

http://tamsler.blogspot.co.uk/2011/11/android-viewpager-and-fragments-part-ii.html

我有一个ViewPager的基础知识,片段工作:

FragmentPagerActivity.java

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;

public class FragmentPagerActivity extends FragmentActivity {

    private static final int NUMBER_OF_PAGES = 10;

    private ViewPager mViewPager;
    private MyFragmentPagerAdapter mMyFragmentPagerAdapter;

    public void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         mViewPager = (ViewPager) findViewById(R.id.viewpager);
         mMyFragmentPagerAdapter = new MyFragmentPagerAdapter(getSupportFragmentManager());
         mViewPager.setAdapter(mMyFragmentPagerAdapter);
    }

    private static class MyFragmentPagerAdapter extends FragmentPagerAdapter {

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

         @Override
         public Fragment getItem(int index) { 

              return PageFragment.newInstance("My Message " + index);
         }  

         @Override 
         public int getCount() {

              return NUMBER_OF_PAGES;
         }
    }
}

PageFragment.java:

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

public class PageFragment extends Fragment {

    public static PageFragment newInstance(String title) {

        PageFragment pageFragment = new PageFragment();
        Bundle bundle = new Bundle();
        bundle.putString("title", title);
        pageFragment.setArguments(bundle);
        return pageFragment;
    }

    @Override  
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

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

        View view = inflater.inflate(R.layout.fragment, container, false);
        TextView textView = (TextView) view.findViewById(R.id.textView1);
        textView.setText(getArguments().getString("title"));
        return view;
    }
}

main.xml中:

<?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:orientation="vertical" >
<android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

</LinearLayout>

fragment.xml之:

<?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="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView" />

</LinearLayout>

我希望能够用我自己的7个已经存在的布局替换ViewPager中的当前布局,并使用Fragments为布局添加功能.我可以用我已经拥有的代码以及为使其正常工作而进行的更改来做什么？

如果有任何带有片段的ViewPager的例子也可以在线获取,而不是像Adroid Developers博客中那样简单地进行,我将非常感激.

Answer 1

在MyFragmentPagerAdapter中声明这个:

private Fragment[] fragments = new Fragment[] { new Fragment1(),Fragment2(),Fragment3(),Fragment4(),Fragment5()};

然后像这样实现getItem方法:

 @Override  
         public Fragment getItem(int index) {  

              return fragments[index];
         } 

并且对于每个片段都有自己的类和布局:

public class Fragment1 extends Fragment { 
   //your code here
}

Answer 2

假设您知道如何自己创建片段,只需执行以下操作即可将它们放入视图寻呼机中:

        @Override
        public Fragment getItem(int page) {
            switch (page) {
                case 0: return new MyFirstFragment();
                case 1: return new MySecondFragment();
                case 2: return new MyThirdFragment();
                //and so on....
            }
            return null;
        }

        @Override
        public int getCount() {
            return [the count of total fragments];
        }

而不是这个:

     @Override  
     public Fragment getItem(int index) {  
          return PageFragment.newInstance("My Message " + index);
     }