Question

我正在测试一个Android项目（http://developer.android.com/training/animation/screen-slide.html），我在一个类中有错误。

/*
 * Copyright 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.screensidetest2;

import android.app.Fragment;
import android.app.FragmentManager;
import android.content.Intent;
import android.os.Bundle;
import android.support.v13.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;

/**
 * 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());
        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();
            }
        });
    }

    @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, 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);
    }

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

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

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

我在libs中添加了jar（我有两个，v13和v4），但错误仍然存在。谢谢。

编辑：将v13更改为v4后，很多错误消失，只剩下2个。

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

超级（FM）;构造函数FragmentStatePageAdapter（FragmentManager）未定义。

和

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

public Fragment getItem（int position） - 返回类型与FragmentStatePageAdapter.getItem（int）不兼容。

Answer 1

我被封锁了一段时间，并设法修复它，

尝试使用getSupportFragmentManager()代替getFragmentManager()。

Answer 2

将“import android.support.v13.app.FragmentActivity”更改为“import android.support.v4.app.FragmentActivity”

对于未定义的部分，请尝试以下语法：

public 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 ScreenSlidePagerAdapter.create(position);
    }

原始建议：您是否已将库添加到构建路径中？只需右键单击该项目，将列出菜单项“Java Build Path”。选择此选项并将库添加到路径中。

Answer 3

以下是供进一步参考的完整代码

package com.team.test;

import android.content.Intent;
import android.content.pm.ActivityInfo;
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;

/**
 * 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 MenuActivity extends FragmentActivity {
    /**
     * The number of pages (wizard steps) to show in this demo.
     */
    private static final int NUM_PAGES = 6;

    /**
     * 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);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        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);
        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();
            }
        });
    }

    @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, Login.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 ScreenSlidePageFragment}
     * objects, in sequence.
     */
    public class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
        public ScreenSlidePagerAdapter(android.support.v4.app.FragmentManager fm) {
            super(fm);
        }

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

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

Answer 4

我想我应该解释一下......

如果你想支持api <11。然后你应该import android.support.v4.app.FragmentPagerAdapter;，然后按import android.support.v4.app.Fragment;创建所有片段，你就完成了。

<强> API == 11

如果您不想支持api <11。或者你只是想使用简单的片段（没有支持）然后你应该import android.support.v13.app.FragmentPagerAdapter;然后getItem将需要一个简单的Fragment。

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

导入android.support.v13.app.FragmentActivity无法解析

4 个答案: