Android Fragment在ViewPager中替换

大致效果如下

 ](https://img.haomeiwen.com/i1168278/ee8e30f37fdcc193.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

在viewPager中有5个fragment，在第二个fragment中有一个切换按钮，可以将自己切换为fragment6，之后点击fragment6中的按钮可以切换回来。。。。参考:

http://blog.csdn.net/z13759561330/article/details/40737381/

具体代码如下

FragmentActivity.class

<pre><code>

package com.lsp.otherandroidtest.fragment_test;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.ViewGroup;

import com.lsp.otherandroidtest.R;

import java.util.ArrayList;
import java.util.List;

/**

• Created by lsp on 2016/8/5.
  */
  public class FragmentViewPagerTest extends AppCompatActivity {
  private ViewPager viewPager;
  private FragmentPagerAdapter adapter;
  private List<Fragment> fragmentList;

  private TestFragment testFragment1;
  private TestFragment testFragment2;
  private TestFragment testFragment3;
  private TestFragment testFragment4;
  private TestFragment testFragment5;

  private TestFragment testFragment6;

  private boolean fragmentsUpdateFlag[] = {false, false, false, false, false};

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

   initViewPager();
  

  }

  private void initViewPager() {

   viewPager = (ViewPager) findViewById(R.id.id_vp);
  
   testFragment1 = TestFragment.getFragment("1");
   testFragment2 = TestFragment.getFragment("2");
   testFragment3 = TestFragment.getFragment("3");
   testFragment4 = TestFragment.getFragment("4");
   testFragment5 = TestFragment.getFragment("5");
  
   testFragment6 = TestFragment.getFragment("6");
  
   fragmentList = new ArrayList<>();
   fragmentList.add(testFragment1);
   fragmentList.add(testFragment2);
   fragmentList.add(testFragment3);
   fragmentList.add(testFragment4);
   fragmentList.add(testFragment5);
  
   adapter = new MyAdapter(getSupportFragmentManager());
   viewPager.setOffscreenPageLimit(5);
   viewPager.setAdapter(adapter);
  
   testFragment2.setTransListener(new TestFragment.onTranslateClick() {
       @Override
       public void onClick(String msg) {
           //点击切换按钮
           //设置fragment2的tag为true
           fragmentsUpdateFlag[1] = true;
           //替换fragment
           fragmentList.set(1, testFragment6);
           adapter.notifyDataSetChanged();
       }
   });
   testFragment6.setTransListener(new TestFragment.onTranslateClick() {
       @Override
       public void onClick(String msg) {
           //点击切换按钮
           //设置fragment2的tag为true
           fragmentsUpdateFlag[1] = true;
           //替换fragment
           fragmentList.set(1, testFragment6);
           //刷新
           adapter.notifyDataSetChanged();
       }
   });
  

  }

public class MyAdapter extends FragmentPagerAdapter {

    private FragmentManager fm;

    public MyAdapter(FragmentManager fm) {
        super(fm);
        this.fm = fm;
    }


    @Override
    public Fragment getItem(int position) {
        return fragmentList.get(position % fragmentList.size());
    }

    @Override
    public int getCount() {
        return fragmentList.size();
    }

    @Override
    public int getItemPosition(Object object) {
        return POSITION_NONE;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        //得到缓存的fragment

        Fragment fragment = (Fragment) super.instantiateItem(container, position);

        //得到tag


        String fragmentTag = fragment.getTag();

        if (fragmentsUpdateFlag[position % fragmentsUpdateFlag.length]) {

            //如果这个fragment需要更新

            FragmentTransaction ft = fm.beginTransaction();

            //移除旧的fragment

            ft.remove(fragment);

            //换成新的fragment

            fragment = fragmentList.get(position % fragmentList.size());

            //添加新fragment时必须用前面获得的tag ❶

            ft.add(container.getId(), fragment, fragmentTag);

            ft.attach(fragment);

            ft.commit();


            //复位更新标志

            fragmentsUpdateFlag[position % fragmentsUpdateFlag.length] = false;

        }


        return fragment;
    }


}

}
</code>
</pre>

FragmentActivity.XML

<pre></code>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.view.ViewPager
android:id="@+id/id_vp"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
</code>
</pre>

TestFragment.class

<pre><code>
package com.lsp.otherandroidtest.fragment_test;

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

import com.lsp.otherandroidtest.R;

/**

• Created by lsp on 2016/8/5.
  */
  public class TestFragment extends Fragment {
  private View view;
  private String msg;
  private onTranslateClick transListener;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    view = inflater.inflate(R.layout.fragment_test,null);
    msg = getArguments().getString("msg");
    ((TextView)view.findViewById(R.id.id_tv)).setText(msg);

    if("2".equals(msg)||"6".equals(msg))
    (view.findViewById(R.id.id_btn)).setVisibility(View.VISIBLE);


    (view.findViewById(R.id.id_btn)).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            transListener.onClick(msg);
        }
    });
    return view;

}

public void setTransListener(onTranslateClick listener){
    this.transListener = listener;
}

public interface onTranslateClick{
    void onClick(String msg);
}

public static TestFragment getFragment(String msg){
    TestFragment testFragment= new TestFragment();
    Bundle bundle = new Bundle();
    bundle.putString("msg",msg);
    testFragment.setArguments(bundle);

    return testFragment;

}

}
</code>
</pre>

TestFragment.xml

<pre><code>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/id_tv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:textSize="16sp" />

<Button
    android:id="@+id/id_btn"
    android:visibility="gone"
    android:layout_marginTop="10dp"
    android:layout_centerHorizontal="true"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/id_tv"
    android:text="切换" />

</RelativeLayout>
</code>
</pre>
这里用来表示要替换的Fragment

Paste_Image.png

在TestFragment中为按钮做了回调，当点击Fragment的按钮时，在FragmentActivity中处理，

Paste_Image.png
这里是点击fragment中的回调处理, Paste_Image.png

最主要的处理部分在instantiateItem方法中..