如何在材料设计中使用 ViewPager 创建工具栏选项卡

Question

有人知道 API 21/AppCompat 工具栏中的 标签 是如何完成的吗？

我发现的很多材料和文章都是旧的。他们对 ActionBar 使用了旧方法，这些方法现在不起作用。此时我刚刚创建了工具栏，对工具栏选项卡一无所知。那么任何人都可以提供有关如何使用 viewpager 制作工具栏选项卡的示例或文章吗？

Answer 1

有人知道 API 21/AppCompat 工具栏中的选项卡是如何完成的吗？

没有Toolbar 选项卡。 Material Design 弃用了在操作栏中包含选项卡的模式，当他们创建 Toolbar 时，他们删除了选项卡。

那么任何人都可以提供有关如何使用 viewpager 制作工具栏选项卡的示例或文章。

没有Toolbar 选项卡。

欢迎您将PagerTabStrip、the ViewPagerIndicator library、PagerSlidingTabStrip 中的TabPageIndicator 等用于您的ViewPager 标签。

Answer 2

1 .从https://developer.android.com/samples/SlidingTabsColors/src/com.example.android.common/view/SlidingTabLayout.html 复制 SlidingTabLayout.java 并将其粘贴到您的包中。

MainActivity.java

public class MainActivity extends ActionBarActivity {

static final String LOG_TAG = "SlidingTabsBasicFragment";
private SlidingTabLayout mSlidingTabLayout;
private ViewPager mViewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_sample);
    Toolbar toolbar = (Toolbar) findViewById(R.id.my_awesome_toolbar);

    mViewPager = (ViewPager) findViewById(R.id.viewpager);
    mViewPager.setAdapter(new SamplePagerAdapter());
    mSlidingTabLayout = (SlidingTabLayout) findViewById(R.id.sliding_tabs);
    mSlidingTabLayout.setViewPager(mViewPager);

    /*
     * FragmentTransaction transaction =
     * getSupportFragmentManager().beginTransaction();
     * SlidingTabsBasicFragment fragment = new SlidingTabsBasicFragment();
     * transaction.replace(R.id.sample_content_fragment, fragment);
     * transaction.commit();
     */

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

class SamplePagerAdapter extends PagerAdapter {

    /**
     * @return the number of pages to display
     */
    @Override
    public int getCount() {
        return 5;
    }

    /**
     * @return true if the value returned from
     *         {@link #instantiateItem(ViewGroup, int)} is the same object
     *         as the {@link View} added to the {@link ViewPager}.
     */
    @Override
    public boolean isViewFromObject(View view, Object o) {
        return o == view;
    }

    // BEGIN_INCLUDE (pageradapter_getpagetitle)
    /**
     * Return the title of the item at {@code position}. This is important
     * as what this method returns is what is displayed in the
     * {@link SlidingTabLayout}.
     * <p>
     * Here we construct one using the position value, but for real
     * application the title should refer to the item's contents.
     */
    @Override
    public CharSequence getPageTitle(int position) {
        return "Item " + (position + 1);
    }

    // END_INCLUDE (pageradapter_getpagetitle)

    /**
     * Instantiate the {@link View} which should be displayed at
     * {@code position}. Here we inflate a layout from the apps resources
     * and then change the text view to signify the position.
     */
    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        // Inflate a new layout from our resources

        View view = getLayoutInflater().inflate(R.layout.pager_item,
                container, false);
        // Add the newly created View to the ViewPager
        container.addView(view);

        // Retrieve a TextView from the inflated View, and update it's text
        TextView title = (TextView) view.findViewById(R.id.item_title);
        title.setText(String.valueOf(position + 1));

        Log.i(LOG_TAG, "instantiateItem() [position: " + position + "]");

        // Return the View
        return view;
    }

    /**
     * Destroy the item from the {@link ViewPager}. In our case this is
     * simply removing the {@link View}.
     */
    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView((View) object);
        Log.i(LOG_TAG, "destroyItem() [position: " + position + "]");
    }

}

}

fragment_sample.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <android.support.v7.widget.Toolbar
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/my_awesome_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:minHeight="?attr/actionBarSize"

        app:theme="@style/ThemeOverlay.AppCompat.ActionBar">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >

            <com.example.android.common.view.SlidingTabLayout
                android:id="@+id/sliding_tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
        </LinearLayout>
    </android.support.v7.widget.Toolbar>

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="0px"
        android:layout_weight="1"
        android:background="@android:color/white" />

</LinearLayout>

Pager_item.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical"
      android:gravity="center">

    <TextView
          android:id="@+id/item_subtitle"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:textAppearance="?android:attr/textAppearanceLarge"
          android:text="Page:"/>

    <TextView
          android:id="@+id/item_title"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:textSize="80sp" />

</LinearLayout>

Answer 3

我创建了一个可以帮助您进行此布局的库，但我没有使用 Toolbar（我使用的是 RelativeLayout）。

我刚刚创建了一个扩展 RelativeLayout 的自定义视图，并在其中放置了所有元素（工具栏的 LinearLayout、标记的 View 和 ViewPager）。

这是 CustomView 类：

public class ToolbarPagerView extends RelativeLayout {

private static final @IdRes int MENU_ID = 0x0042;
private static final @IdRes int PAGER_ID = 0x0666;

private int totalPages;
private int currentPage;
private @ColorInt int toolbarColor;
private @ColorInt int itemColor;
private ToolbarPagerAdapter toolbarPagerAdapter;
private LinearLayout menu;
private ViewPager viewPager;
private View marker;

public ToolbarPagerView(Context context, AttributeSet attrs) {
    super(context, attrs);
    initialize(context, attrs);
}

public ToolbarPagerView(Context context, AttributeSet attrs, int defStyleAttr) {
    this(context, attrs, defStyleAttr, 0);
    initialize(context, attrs);
}

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public ToolbarPagerView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
    super(context, attrs, defStyleAttr, defStyleRes);
    initialize(context, attrs);
}

private void initialize(Context context, AttributeSet attrs) {
    /* RETRIEVE MAX PAGES */
    TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.ToolbarPagerView);
    try {
        toolbarColor = attributes.getInteger(R.styleable.ToolbarPagerView_toolbar_color, R.color.color_primary_dark);
        itemColor = attributes.getInteger(R.styleable.ToolbarPagerView_item_color, R.color.color_accent);
    } finally {
        attributes.recycle();
        setViews(context);
    }
}

private void setViews(Context context) {
    /* MENU */
    menu = new LinearLayout(context);
    menu.setId(MENU_ID);
    menu.setOrientation(LinearLayout.HORIZONTAL);
    menu.setBackgroundColor(toolbarColor);
    menu.setGravity(Gravity.CENTER);

    addView(menu);

    LayoutParams menuParams = (LayoutParams) menu.getLayoutParams();

    TypedArray toolbarAttributes = context.getTheme().obtainStyledAttributes(new int[] { android.R.attr.actionBarSize });
    menuParams.width = ViewGroup.LayoutParams.MATCH_PARENT;
    menuParams.height = (int) toolbarAttributes.getDimension(0, 0);

    /* PAGES */
    viewPager = new ViewPager(context);
    viewPager.setId(PAGER_ID);

    addView(viewPager);

    LayoutParams pagerParams = (LayoutParams) viewPager.getLayoutParams();
    pagerParams.width = ViewGroup.LayoutParams.MATCH_PARENT;
    pagerParams.height = ViewGroup.LayoutParams.MATCH_PARENT;
    pagerParams.addRule(BELOW, MENU_ID);

    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            marker.setX((positionOffsetPixels / totalPages) + (marker.getMeasuredWidth() * position));
        }

        @Override
        public void onPageSelected(int position) {
            currentPage = position;
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

    /* SHADOW */
    View shadow = new View(context);
    shadow.setBackgroundResource(R.drawable.shadow);

    addView(shadow);

    LayoutParams shadowParams = (LayoutParams) shadow.getLayoutParams();

    shadowParams.width = ViewGroup.LayoutParams.MATCH_PARENT;
    shadowParams.height = (int) context.getResources().getDimension(R.dimen.shadow_height);

    shadowParams.addRule(BELOW, MENU_ID);

    /* MARKER */
    marker = new View(context);
    marker.setBackgroundColor(itemColor);

    addView(marker);

    LayoutParams markerParams = (LayoutParams) marker.getLayoutParams();
    markerParams.height = (int) context.getResources().getDimension(R.dimen.marker_height);
    markerParams.addRule(ALIGN_BOTTOM, MENU_ID);

    getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            if(Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) {
                getViewTreeObserver().removeGlobalOnLayoutListener(this);
            } else {
                getViewTreeObserver().removeOnGlobalLayoutListener(this);
            }

            LayoutParams markerParams = (LayoutParams) marker.getLayoutParams();
            markerParams.width = menu.getMeasuredWidth() / totalPages;
            marker.setX(currentPage * markerParams.width);
        }
    });
}

public void setAdapter(FragmentManager fragmentManager) {
    toolbarPagerAdapter = new ToolbarPagerAdapter(fragmentManager);
    viewPager.setAdapter(toolbarPagerAdapter);
}

public void addPage(Fragment fragment) {
    addPage(R.mipmap.ic_star, fragment);
}

public void addPage(@DrawableRes int icon, Fragment fragment) {
    ImageView item = new ImageView(getContext());

    item.setImageResource(icon);
    item.setTag(totalPages);
    item.setColorFilter(itemColor);

    TypedArray selectAttributes = getContext().obtainStyledAttributes(new int[]{android.R.attr.selectableItemBackground});

    if(Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) {
        item.setBackgroundDrawable(selectAttributes.getDrawable(0));
    } else {
        item.setBackground(selectAttributes.getDrawable(0));
    }

    menu.setWeightSum(++totalPages);
    menu.addView(item);

    item.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            Integer itemPosition = (Integer) v.getTag();
            viewPager.setCurrentItem(itemPosition);
        }
    });

    LinearLayout.LayoutParams itemParams = (LinearLayout.LayoutParams) item.getLayoutParams();

    itemParams.width = ViewGroup.LayoutParams.MATCH_PARENT;
    itemParams.height = ViewGroup.LayoutParams.MATCH_PARENT;
    itemParams.weight = 1;

    toolbarPagerAdapter.addPage(fragment);
}
}

这是 CustomAdapter 类：

public class ToolbarPagerAdapter extends FragmentPagerAdapter {

private static final String PAGE_DUPLICATED_MESSAGE = "You're trying to add a duplicated page, are you doublethinking? - Orwell, George / Index: ";

private ArrayList<Fragment> pages;

public ToolbarPagerAdapter(FragmentManager fm) {
    super(fm);
    pages = new ArrayList<>();
}

public void addPage(Fragment fragment) {
    pages.add(fragment);
    notifyDataSetChanged();
}

@Override
public Fragment getItem(int position) {
    return pages.get(position);
}

@Override
public int getCount() {
    return pages.size();
}
}

您可以在这里找到我基于此解决方案创建的演示项目：

https://github.com/PedroOkawa/toolbar-pager-view

如果需要，请查看代码，希望对您有所帮助。