我试图在 http://developer.android.com/training/animation/screen-slide.html 中实现一个 android 项目我在一节课上有一个错误

import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.content.Intent;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.app.NavUtils;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

public class MainActivity extends FragmentActivity {
 private static final int NUM_PAGES = 5;
 private ViewPager mPager;
 private PagerAdapter mPagerAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mPager = (ViewPager) findViewById(R.id.pager);
    mPagerAdapter = new ScreenSlidePagerAdapter(getFragmentManager());
    mPager.setAdapter(mPagerAdapter);
    mPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            // When changing pages, reset the action bar actions since they are dependent
            // on which page is currently active. An alternative approach is to have each
            // fragment expose actions itself (rather than the activity exposing actions),
            // but for simplicity, the activity provides the actions in this sample.
            invalidateOptionsMenu();
        }
    });
}
@SuppressLint("NewApi")
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    getMenuInflater().inflate(R.menu.activity_main, menu);

    menu.findItem(R.id.action_previous).setEnabled(mPager.getCurrentItem() > 0);

    // Add either a "next" or "finish" button to the action bar, depending on which       page
    // is currently selected.
    MenuItem item = menu.add(Menu.NONE, R.id.action_next, Menu.NONE,
            (mPager.getCurrentItem() == mPagerAdapter.getCount() - 1)
                    ? R.string.action_finish
                    : R.string.action_next);
    item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM | MenuItem.SHOW_AS_ACTION_WITH_TEXT);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            // Navigate "up" the demo structure to the launchpad activity.
            // See http://developer.android.com/design/patterns/navigation.html for more.
            NavUtils.navigateUpTo(this, new Intent(this, MainActivity.class));
            return true;

        case R.id.action_previous:
            // Go to the previous step in the wizard. If there is no previous step,
            // setCurrentItem will do nothing.
            mPager.setCurrentItem(mPager.getCurrentItem() - 1);
            return true;

        case R.id.action_next:
            // Advance to the next step in the wizard. If there is no next step, setCurrentItem
            // will do nothing.
            mPager.setCurrentItem(mPager.getCurrentItem() + 1);
            return true;
    }

    return super.onOptionsItemSelected(item);
}


     private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
      public ScreenSlidePagerAdapter(FragmentManager fm) {
         super(fm);
     }

 public Fragment getItem(int position) {
        return ScreenSlidePageFragment.create(position);
    }


    public int getCount() {
        return NUM_PAGES;
    }
}
    }

我在 android 4.2 中构建项目。

编辑:我已将代码更改为

private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
    public ScreenSlidePagerAdapter(android.support.v4.app.FragmentManager fm) {
        super(fm);
    }

和

 @Override
    public android.support.v4.app.Fragment getItem(int position) {
        return Firstframe.create(position);
    }

然后出现错误

mPagerAdapter = new ScreenSlidePagerAdapter(getFragmentManager());

错误:构造函数 MainActivity.ScreenSlidePagerAdapter(FragmentManager) 未定义

最佳答案

取而代之的是:

mPagerAdapter = new ScreenSlidePagerAdapter(getFragmentManager());

这样做:

mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());

因为

getFragmentManager() 配合 import android.app.FragmentManager

和

getSupportFragmentManager() 配合 android.support.v4.app.FragmentManager

关于java - 错误 : The constructor MainActivity. ScreenSlidePagerAdapter(FragmentManager) 未定义，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14950833/