Question

我今天下载了示例屏幕滑动并希望在我的项目中测试它，但不得不停止，因为存在一些不兼容类型的返回值的问题... https://developer.android.com/training/animation/screen-slide.html 这就是我下载的地方。

ScreenSlideActivity：

package ur.mi.android.wgplus05.FotoApp;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
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.Menu;
import android.view.MenuItem;

import ur.mi.android.wgplus05.R;

/**
 * Demonstrates a "screen-slide" animation using a {@link ViewPager}.         Because {@link ViewPager}
 * automatically plays such an animation when calling {@link
 ViewPager#setCurrentItem(int)}, there
 * isn't any animation-specific code in this sample.
 *
 * <p>This sample shows a "next" button that advances the user to the     

next step in a wizard,
 * animating the current screen out (to the left) and the next screen in     

(from the right). The
 * reverse animation is played when the user presses the "previous" 
button.</p>
 *
 * @see ScreenSlidePageFragment
 */
public class ScreenSlideActivity extends FragmentActivity {
/**
 * The number of pages (wizard steps) to show in this demo.
 */
private static final int NUM_PAGES = 5;

/**
 * The pager widget, which handles animation and allows swiping horizontally to access previous
 * and next wizard steps.
 */
private ViewPager mPager;

/**
 * The pager adapter, which provides the pages to the view pager widget.
 */
private PagerAdapter mPagerAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_screen_slide);

    // Instantiate a ViewPager and a PagerAdapter.
    mPager = (ViewPager) findViewById(R.id.pager);
    mPagerAdapter = new ScreenSlidePagerAdapter(getFragmentManager());

  **//ScreenSlidePagerAdapter
  (android.support.v4.app.FragmentManager)
  in ScreenSlidePagerAdapter cannot be applied
  to android.app.FragmentManager)**

    mPager.setAdapter(mPagerAdapter);
    mPager.addOnPageChangeListener(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();
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    getMenuInflater().inflate(R.menu.activity_screen_slide, 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, FotoWand.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);
}

/**
 * A simple pager adapter that represents 5 {@link CustomScreenSlidePageFragment} objects, in
 * sequence.
 */
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
    public ScreenSlidePagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        return ScreenSlidePageFragment.create(position);
 **// Incompatible types.
 Required:
 android.support.v4.app.Fragment
 Found: ur.mi.android.wgplus05.FotoApp.ScreenSlidePageFragment**
    }

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

ScreenSliderPagerActivity：

package ur.mi.android.wgplus05.FotoApp;

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.FragmentStatePagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;

import ur.mi.android.wgplus05.R;

public class ScreenSlidePagerActivity extends FragmentActivity {
/**
 * The number of pages (wizard steps) to show in this demo.
 */
private static final int NUM_PAGES = 5;

/**
 * The pager widget, which handles animation and allows swiping horizontally to access previous
 * and next wizard steps.
 */
private ViewPager mPager;

/**
 * The pager adapter, which provides the pages to the view pager widget.
 */
private PagerAdapter mPagerAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_screen_slide);

    // Instantiate a ViewPager and a PagerAdapter.
    mPager = (ViewPager) findViewById(R.id.pager);
    mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
    mPager.setAdapter(mPagerAdapter);
}

@Override
public void onBackPressed() {
    if (mPager.getCurrentItem() == 0) {
        // If the user is currently looking at the first step, allow the system to handle the
        // Back button. This calls finish() on this activity and pops the back stack.
        super.onBackPressed();
    } else {
        // Otherwise, select the previous step.
        mPager.setCurrentItem(mPager.getCurrentItem() - 1);
    }
}

/**
 * A simple pager adapter that represents 5 ScreenSlidePageFragment objects, in
 * sequence.
 */
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
    public ScreenSlidePagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        return new ScreenSlidePageFragment();
   ** // Incompatible types.
  Required:
  android.support.v4.app.Fragment
  Found:ur.mi.android.wgplus05.FotoApp.ScreenSlidePageFragment**
    }

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

我标记了我得到的错误** 我对此完全陌生，并且没有发现这一切是如何一起工作的。希望有人可以帮助我！提前谢谢。

  package ur.mi.android.wgplus05.FotoApp;

 import android.app.Fragment;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;

 import ur.mi.android.wgplus05.R;

 public class ScreenSlidePageFragment extends Fragment {
/**
 * The argument key for the page number this fragment represents.
 */
public static final String ARG_PAGE = "page";

/**
 * The fragment's page number, which is set to the argument value for {@link #ARG_PAGE}.
 */
private int mPageNumber;

/**
 * Factory method for this fragment class. Constructs a new fragment for the given page number.
 */
public static ScreenSlidePageFragment create(int pageNumber) {
    ScreenSlidePageFragment fragment = new ScreenSlidePageFragment();
    Bundle args = new Bundle();
    args.putInt(ARG_PAGE, pageNumber);
    fragment.setArguments(args);
    return fragment;
}

public ScreenSlidePageFragment() {
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mPageNumber = getArguments().getInt(ARG_PAGE);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout containing a title and body text.
    ViewGroup rootView = (ViewGroup) inflater
            .inflate(R.layout.fragment_screen_slide_page, container, false);

    // Set the title view to show the page number.
    ((TextView) rootView.findViewById(android.R.id.text1)).setText(
            getString(R.string.title_template_step, mPageNumber + 1));

    return rootView;
}

/**
 * Returns the page number represented by this fragment object.
 */
public int getPageNumber() {
    return mPageNumber;
}

}

Answer 1

您正在为android.app.Fragment而不是ScreenSlidePageFragment

延长android.support.v4.app.Fragment

定义您的ScreenSlidePageFragment，如下所示

 public class ScreenSlidePageFragment extends android.support.v4.app.Fragment

这将解决您的问题

使用ViewPager进行屏幕幻灯片不兼容的类型

1 个答案: