Android应用中利用ViewPager实现多页面滑动切换效果示例

2019-12-10 18:38:43王振洲

其中的myPagerAdapter集成自ragmentPagerAdapter,为ViewPager提供数据源。

onCreate函数得到ViewPager实例并设置数据源,getSupportFragmentManager表示得到Fragment管理器。ViewPagerFragment1表示具体的页面,见下面介绍。

4、新建Fragment页面
Fragment页面即为左右滑动需要显示的页面,新建类集成Fragment,并重写onCreateView函数即可。onCreateView函数相当于Activity的onCreate函数。如下:

public class ViewPagerFragment1 extends Fragment {

  private String  text;
  private TextView tv = null;

  public ViewPagerFragment1(String text){
    super();
    this.text = text;
  }

  /**
   * 覆盖此函数,先通过inflater inflate函数得到view最后返回
   */
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.view_pager_fragment_demo1, container, false);
    tv = (TextView)v.findViewById(R.id.viewPagerText);
    tv.setText(text);
    return v;
  }
}

5、示例工程代码:

package cn.trinea.android.demo;

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

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.view.ViewPager;

public class ViewPagerDemo extends BaseFragmentActivity {

  private static int TOTAL_COUNT = 3;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState, R.layout.view_pager_demo);

    ViewPager vp = (ViewPager)findViewById(R.id.view_pager);
    List<Fragment> fragmentList = new ArrayList<Fragment>();
    List<String> titleList = new ArrayList<String>();
    for (int i = 0; i < TOTAL_COUNT; i++) {
      ViewPagerFragment viewPagerFragment1 = new ViewPagerFragment();
      Bundle bundle = new Bundle();
      bundle.putInt("upImageId", 0);
      bundle.putString("text", "Page " + i);
      viewPagerFragment1.setArguments(bundle);
      titleList.add("title " + i);
      fragmentList.add(viewPagerFragment1);
    }

    vp.setAdapter(new myPagerAdapter(getSupportFragmentManager(), fragmentList, titleList));

  }

  class myPagerAdapter extends FragmentPagerAdapter {

    private List<Fragment> fragmentList;
    private List<String>  titleList;

    public myPagerAdapter(FragmentManager fm, List<Fragment> fragmentList, List<String> titleList) {
      super(fm);
      this.fragmentList = fragmentList;
      this.titleList = titleList;
    }

    @Override
    public Fragment getItem(int arg0) {
      return (fragmentList == null || fragmentList.size() == 0) ? null : fragmentList.get(arg0);
    }

    @Override
    public CharSequence getPageTitle(int position) {
      return (titleList.size() > position) ? titleList.get(position) : "";
    }

    @Override
    public int getCount() {
      return fragmentList == null ? 0 : fragmentList.size();
    }
  }
}