我正在使用片段和pageview尝试使用水平寻呼机,我得到以下错误：

Cannot instantiate the type PagerAdapter.

我知道PagerAdapter是一个抽象类,所以我创建了一个继承自PagerAdapter并使用它的新类.

但没有解决它.

这是我的代码：

主要活动进口

import java.util.List;

import java.util.Vector;

import android.os.Bundle;

import android.support.v4.app.Fragment;

import android.support.v4.view.ViewPager;

import android.support.v7.app.ActionBarActivity;

import android.view.Menu;

import android.view.MenuItem;

//import com.example.prova.PagerAdapter;

//import android.support.v4.view.PagerAdapter;

我尝试创建pageradapter时出现错误的主要活动

public class MainActivity extends ActionBarActivity {

List fragments = new Vector();

private ViewPager mPager;

PagerAdapter mPagerAdapter;

//mPager.setCurrentItem(2);

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

// creating fragments and adding to list

fragments.add(Fragment.instantiate(this,Timeline.class.getName()));

fragments.add(Fragment.instantiate(this,Postit.class.getName()));

fragments.add(Fragment.instantiate(this,Frase.class.getName()));

fragments.add(Fragment.instantiate(this,Impostazioni.class.getName()));

// creating adapter and linking to view pager

this.mPagerAdapter=new PagerAdapter(super.getSupportFragmentManager(),fragments); //I GOT HERE THE ERROR

mPager = (ViewPager) super.findViewById(R.id.pager);

mPager.setAdapter(this.mPagerAdapter);

}

在这里我的PagerAdapter

public abstract class PagerAdapter extends FragmentPagerAdapter {

// fragments to instantiate in the viewpager

private List fragments;

// constructor

public PagerAdapter(FragmentManager fm,List fragments) {

super(fm);

this.fragments = fragments;

}

// return access to fragment from position, required override

@Override

public Fragment getItem(int position) {

return this.fragments.get(position);

}

// number of fragments in list, required override

@Override

public int getCount() {

return this.fragments.size();

}

}