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我还将 3 个片段页面视图声明为 PageView。我的应用程序在我运行后没有响应,没有错误。我参考了这个 youtube 视频 https://www.youtube.com/watch?v=NYjgX-GNRGo。我认为这段代码已经过时了。有人可以告诉我如何纠正这个吗?

包 com.example.name.scrollable;

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.View;

  public class MainActivity extends FragmentActivity
  {    
      ViewPager mViewPager = null;
      @Override
      protected void onCreate(Bundle savedInstanceState)
     {    
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);

         mViewPager = (ViewPager) mViewPager.findViewById(R.id.pager);
         FragmentManager fragmentManager = getSupportFragmentManager();
         mViewPager.setAdapter(new MyFragmentAdapter(fragmentManager));
     }    
  }

 class MyFragmentAdapter extends FragmentPagerAdapter
{    
    public MyFragmentAdapter(FragmentManager fm)
    {
        super(fm);    
    }

    @Override
    public Fragment getItem(int position)
    {
        Fragment fragment = null;

        if(position == 0)
        {
            fragment = new Fragment_a();
        }

        if(position == 1)
        {
            fragment = new Fragment_b();
        }

        if (position == 2)
        {
            fragment = new Fragment_c();
        }
        return fragment;
    }

      @Override
     public int getCount()
     {
        return 3;
     }
}

我还制作了 3 个片段页面显示我可以在 ViewPager 的帮助下显示吗

4

1 回答 1

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添加这个:

mViewPager = (ViewPager)findViewById(R.id.pager);

而不是这个:

mViewPager = (ViewPager) mViewPager.findViewById(R.id.pager);
于 2017-03-05T18:32:34.000 回答