Android Studio - 滑动选项卡显示在操作栏下方而不是操作栏上

Question

我创建了一组带有视图寻呼机的滑动选项卡以放入我的 activity_main.xml。在项目中，选项卡显示在操作栏下方，就像它们被分开一样。

我想让它们看起来像是操作栏的一部分。

我应该在我的代码中编辑什么来完成这个？

MainActivity.java

package com.davidreadiii.android.slidingtabexample;

import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;

import com.davidreadiii.android.slidingtabexample.tabs.mFragmentPagerAdapter;
import com.davidreadiii.android.slidingtabexample.tabs.SlidingTabLayout;


public class MainActivity extends ActionBarActivity {

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

    // Get the ViewPager and set it's PagerAdapter so that it can display items
    ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
    viewPager.setAdapter(new mFragmentPagerAdapter(getSupportFragmentManager(),
            MainActivity.this));

    // Give the SlidingTabLayout the ViewPager
    SlidingTabLayout slidingTabLayout = (SlidingTabLayout) findViewById(R.id.sliding_tabs);
    // Center the tabs in the layout
    slidingTabLayout.setDistributeEvenly(true);
    slidingTabLayout.setViewPager(viewPager);

    // Customizes the tab indicator color.
    slidingTabLayout.setCustomTabColorizer(new SlidingTabLayout.TabColorizer() {
        @Override
        public int getIndicatorColor(int position) {
            return getResources().getColor(R.color.accentColor);
        }
    });
}


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

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

SlidingTabLayout.java

    package com.davidreadiii.android.slidingtabexample.tabs;

import android.content.Context;
import android.graphics.Typeface;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class SlidingTabLayout extends HorizontalScrollView {

public interface TabColorizer {

    int getIndicatorColor(int position);

}

private static final int TITLE_OFFSET_DIPS = 24;
private static final int TAB_VIEW_PADDING_DIPS = 16;
private static final int TAB_VIEW_TEXT_SIZE_SP = 12;

private int mTitleOffset;

private int mTabViewLayoutId;
private int mTabViewTextViewId;
private boolean mDistributeEvenly;

private ViewPager mViewPager;
private SparseArray<String> mContentDescriptions = new SparseArray<String>();
private ViewPager.OnPageChangeListener mViewPagerPageChangeListener;

private final SlidingTabStrip mTabStrip;

public SlidingTabLayout(Context context) {
    this(context, null);
}

public SlidingTabLayout(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
}

public SlidingTabLayout(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);

    // Disable the Scroll Bar
    setHorizontalScrollBarEnabled(false);
    // Make sure that the Tab Strips fills this View
    setFillViewport(true);

    mTitleOffset = (int) (TITLE_OFFSET_DIPS * getResources().getDisplayMetrics().density);

    mTabStrip = new SlidingTabStrip(context);
    addView(mTabStrip, LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
}


public void setSelectedIndicatorColors(int... colors) {
    mTabStrip.setSelectedIndicatorColors(colors);
}

/**
 * Set the {@link ViewPager.OnPageChangeListener}. When using {@link SlidingTabLayout} you are
 * required to set any {@link ViewPager.OnPageChangeListener} through this method. This is so
 * that the layout can update it's scroll position correctly.
 *
 * @see ViewPager#setOnPageChangeListener(ViewPager.OnPageChangeListener)
 */
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mViewPagerPageChangeListener = listener;
}

/**
 * Set the custom layout to be inflated for the tab views.
 *
 * @param layoutResId Layout id to be inflated
 * @param textViewId id of the {@link TextView} in the inflated view
 */
public void setCustomTabView(int layoutResId, int textViewId) {
    mTabViewLayoutId = layoutResId;
    mTabViewTextViewId = textViewId;
}

/**
 * Sets the associated view pager. Note that the assumption here is that the pager content
 * (number of tabs and tab titles) does not change after this call has been made.
 */
public void setViewPager(ViewPager viewPager) {
    mTabStrip.removeAllViews();

    mViewPager = viewPager;
    if (viewPager != null) {
        viewPager.setOnPageChangeListener(new InternalViewPagerListener());
        populateTabStrip();
    }
}

/**
 * Create a default view to be used for tabs. This is called if a custom tab view is not set via
 * {@link #setCustomTabView(int, int)}.
 */
protected TextView createDefaultTabView(Context context) {
    TextView textView = new TextView(context);
    textView.setGravity(Gravity.CENTER);
    textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, TAB_VIEW_TEXT_SIZE_SP);
    textView.setTypeface(Typeface.DEFAULT_BOLD);
    textView.setLayoutParams(new LinearLayout.LayoutParams(
            ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));

    TypedValue outValue = new TypedValue();
    getContext().getTheme().resolveAttribute(android.R.attr.selectableItemBackground,
            outValue, true);
    textView.setBackgroundResource(outValue.resourceId);
    textView.setAllCaps(true);

    int padding = (int) (TAB_VIEW_PADDING_DIPS * getResources().getDisplayMetrics().density);
    textView.setPadding(padding, padding, padding, padding);

    return textView;
}

private void populateTabStrip() {
    final PagerAdapter adapter = mViewPager.getAdapter();
    final View.OnClickListener tabClickListener = new TabClickListener();

    for (int i = 0; i < adapter.getCount(); i++) {
        View tabView = null;
        TextView tabTitleView = null;

        if (mTabViewLayoutId != 0) {
            // If there is a custom tab view layout id set, try and inflate it
            tabView = LayoutInflater.from(getContext()).inflate(mTabViewLayoutId, mTabStrip,
                    false);
            tabTitleView = (TextView) tabView.findViewById(mTabViewTextViewId);
        }

        if (tabView == null) {
            tabView = createDefaultTabView(getContext());
        }

        if (tabTitleView == null && TextView.class.isInstance(tabView)) {
            tabTitleView = (TextView) tabView;
        }

        if (mDistributeEvenly) {
            LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) tabView.getLayoutParams();
            lp.width = 0;
            lp.weight = 1;
        }

        tabTitleView.setText(adapter.getPageTitle(i));
        tabView.setOnClickListener(tabClickListener);
        String desc = mContentDescriptions.get(i, null);
        if (desc != null) {
            tabView.setContentDescription(desc);
        }

        mTabStrip.addView(tabView);
        if (i == mViewPager.getCurrentItem()) {
            tabView.setSelected(true);
        }
    }
}

public void setContentDescription(int i, String desc) {
    mContentDescriptions.put(i, desc);
}

@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();

    if (mViewPager != null) {
        scrollToTab(mViewPager.getCurrentItem(), 0);
    }
}

private void scrollToTab(int tabIndex, int positionOffset) {
    final int tabStripChildCount = mTabStrip.getChildCount();
    if (tabStripChildCount == 0 || tabIndex < 0 || tabIndex >= tabStripChildCount) {
        return;
    }

    View selectedChild = mTabStrip.getChildAt(tabIndex);
    if (selectedChild != null) {
        int targetScrollX = selectedChild.getLeft() + positionOffset;

        if (tabIndex > 0 || positionOffset > 0) {
            // If we're not at the first child and are mid-scroll, make sure we obey the offset
            targetScrollX -= mTitleOffset;
        }

        scrollTo(targetScrollX, 0);
    }
}

private class InternalViewPagerListener implements ViewPager.OnPageChangeListener {
    private int mScrollState;

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        int tabStripChildCount = mTabStrip.getChildCount();
        if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
            return;
        }

        mTabStrip.onViewPagerPageChanged(position, positionOffset);

        View selectedTitle = mTabStrip.getChildAt(position);
        int extraOffset = (selectedTitle != null)
                ? (int) (positionOffset * selectedTitle.getWidth())
                : 0;
        scrollToTab(position, extraOffset);

        if (mViewPagerPageChangeListener != null) {
            mViewPagerPageChangeListener.onPageScrolled(position, positionOffset,
                    positionOffsetPixels);
        }
    }

    @Override
    public void onPageScrollStateChanged(int state) {
        mScrollState = state;

        if (mViewPagerPageChangeListener != null) {
            mViewPagerPageChangeListener.onPageScrollStateChanged(state);
        }
    }

    @Override
    public void onPageSelected(int position) {
        if (mScrollState == ViewPager.SCROLL_STATE_IDLE) {
            mTabStrip.onViewPagerPageChanged(position, 0f);
            scrollToTab(position, 0);
        }
        for (int i = 0; i < mTabStrip.getChildCount(); i++) {
            mTabStrip.getChildAt(i).setSelected(position == i);
        }
        if (mViewPagerPageChangeListener != null) {
            mViewPagerPageChangeListener.onPageSelected(position);
        }
    }

}

private class TabClickListener implements View.OnClickListener {
    @Override
    public void onClick(View v) {
        for (int i = 0; i < mTabStrip.getChildCount(); i++) {
            if (v == mTabStrip.getChildAt(i)) {
                mViewPager.setCurrentItem(i);
                return;
            }
        }
    }
}

}

SlidingTabStrip.java

package com.davidreadiii.android.slidingtabexample.tabs;

import android.R;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
import android.widget.LinearLayout;

class SlidingTabStrip extends LinearLayout {

private static final int DEFAULT_BOTTOM_BORDER_THICKNESS_DIPS = 0;
private static final byte DEFAULT_BOTTOM_BORDER_COLOR_ALPHA = 0x26;
private static final int SELECTED_INDICATOR_THICKNESS_DIPS = 3;
private static final int DEFAULT_SELECTED_INDICATOR_COLOR = 0xFF33B5E5;

private final int mBottomBorderThickness;
private final Paint mBottomBorderPaint;

private final int mSelectedIndicatorThickness;
private final Paint mSelectedIndicatorPaint;

private final int mDefaultBottomBorderColor;

private int mSelectedPosition;
private float mSelectionOffset;

private SlidingTabLayout.TabColorizer mCustomTabColorizer;
private final SimpleTabColorizer mDefaultTabColorizer;

SlidingTabStrip(Context context) {
    this(context, null);
}

SlidingTabStrip(Context context, AttributeSet attrs) {
    super(context, attrs);
    setWillNotDraw(false);

    final float density = getResources().getDisplayMetrics().density;

    TypedValue outValue = new TypedValue();
    context.getTheme().resolveAttribute(R.attr.colorForeground, outValue, true);
    final int themeForegroundColor =  outValue.data;

    mDefaultBottomBorderColor = setColorAlpha(themeForegroundColor,
            DEFAULT_BOTTOM_BORDER_COLOR_ALPHA);

    mDefaultTabColorizer = new SimpleTabColorizer();
    mDefaultTabColorizer.setIndicatorColors(DEFAULT_SELECTED_INDICATOR_COLOR);

    mBottomBorderThickness = (int) (DEFAULT_BOTTOM_BORDER_THICKNESS_DIPS * density);
    mBottomBorderPaint = new Paint();
    mBottomBorderPaint.setColor(mDefaultBottomBorderColor);

    mSelectedIndicatorThickness = (int) (SELECTED_INDICATOR_THICKNESS_DIPS * density);
    mSelectedIndicatorPaint = new Paint();
}

void setCustomTabColorizer(SlidingTabLayout.TabColorizer customTabColorizer) {
    mCustomTabColorizer = customTabColorizer;
    invalidate();
}

void setSelectedIndicatorColors(int... colors) {
    // Make sure that the custom colorizer is removed
    mCustomTabColorizer = null;
    mDefaultTabColorizer.setIndicatorColors(colors);
    invalidate();
}

void onViewPagerPageChanged(int position, float positionOffset) {
    mSelectedPosition = position;
    mSelectionOffset = positionOffset;
    invalidate();
}

@Override
protected void onDraw(Canvas canvas) {
    final int height = getHeight();
    final int childCount = getChildCount();
    final SlidingTabLayout.TabColorizer tabColorizer = mCustomTabColorizer != null
            ? mCustomTabColorizer
            : mDefaultTabColorizer;

    // Thick colored underline below the current selection
    if (childCount > 0) {
        View selectedTitle = getChildAt(mSelectedPosition);
        int left = selectedTitle.getLeft();
        int right = selectedTitle.getRight();
        int color = tabColorizer.getIndicatorColor(mSelectedPosition);

        if (mSelectionOffset > 0f && mSelectedPosition < (getChildCount() - 1)) {
            int nextColor = tabColorizer.getIndicatorColor(mSelectedPosition + 1);
            if (color != nextColor) {
                color = blendColors(nextColor, color, mSelectionOffset);
            }

            // Draw the selection partway between the tabs
            View nextTitle = getChildAt(mSelectedPosition + 1);
            left = (int) (mSelectionOffset * nextTitle.getLeft() +
                    (1.0f - mSelectionOffset) * left);
            right = (int) (mSelectionOffset * nextTitle.getRight() +
                    (1.0f - mSelectionOffset) * right);
        }

        mSelectedIndicatorPaint.setColor(color);

        canvas.drawRect(left, height - mSelectedIndicatorThickness, right,
                height, mSelectedIndicatorPaint);
    }

    // Thin underline along the entire bottom edge
    canvas.drawRect(0, height - mBottomBorderThickness, getWidth(), height, mBottomBorderPaint);
}

/**
 * Set the alpha value of the {@code color} to be the given {@code alpha} value.
 */
private static int setColorAlpha(int color, byte alpha) {
    return Color.argb(alpha, Color.red(color), Color.green(color), Color.blue(color));
}

/**
 * Blend {@code color1} and {@code color2} using the given ratio.
 *
 * @param ratio of which to blend. 1.0 will return {@code color1}, 0.5 will give an even blend,
 *              0.0 will return {@code color2}.
 */
private static int blendColors(int color1, int color2, float ratio) {
    final float inverseRation = 1f - ratio;
    float r = (Color.red(color1) * ratio) + (Color.red(color2) * inverseRation);
    float g = (Color.green(color1) * ratio) + (Color.green(color2) * inverseRation);
    float b = (Color.blue(color1) * ratio) + (Color.blue(color2) * inverseRation);
    return Color.rgb((int) r, (int) g, (int) b);
}

private static class SimpleTabColorizer implements SlidingTabLayout.TabColorizer {
    private int[] mIndicatorColors;

    @Override
    public final int getIndicatorColor(int position) {
        return mIndicatorColors[position % mIndicatorColors.length];
    }

    void setIndicatorColors(int... colors) {
        mIndicatorColors = colors;
    }
}
}

mFragmentPagerAdapter.java

package com.davidreadiii.android.slidingtabexample.tabs;

import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

import com.davidreadiii.android.slidingtabexample.fragments.FragmentPage1;

public class mFragmentPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 3;
private String tabTitles[] = new String[] { "Tab Uno", "Tab Dos", "Tab Tres" };
private Context context;

public mFragmentPagerAdapter(FragmentManager fm, Context context) {
    super(fm);
    this.context = context;
}

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

@Override
public Fragment getItem(int position) {
    return FragmentPage1.newInstance(position + 1);
}

@Override
public CharSequence getPageTitle(int position) {
    // Generate title based on item position
    return tabTitles[position];
}
}

activity_main.xml（以防重要）

<?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">

<!-- Sliding Tab Layout Implementation -->
<com.davidreadiii.android.slidingtabexample.tabs.SlidingTabLayout
    android:id="@+id/sliding_tabs"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/primaryColor">
</com.davidreadiii.android.slidingtabexample.tabs.SlidingTabLayout>

<!-- View Pager Implementation -->
<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>

我在网上搜索了答案，但没有找到适合我的特定项目的答案。

Answer 1

为了回答我自己的问题，需要几个步骤才能实现。首先，您需要在单独的 XML 文件中创建您自己的自定义操作栏。然后，您需要将 "NoActionBar" 主题应用到 activity，您想要将带有 silding 选项卡的操作栏放入其中。然后您需要在 Java 中写入您要设置的操作将特定 activity 中的栏添加到您自己的自定义操作栏。那么我相信，不要引用我，您需要在操作栏布局文件中添加滑动选项卡以及视图分页器。

明明有很多步骤，很难用这种方式来解释。如果您是视觉学习者，SlideNerd 有一套关于如何执行此操作的极好的视频教程。

CustomActionBar 教程（视频 3-5）：https://www.youtube.com/watch?v=pMO8EVkhJO8&index=3&list=PLonJJ3BVjZW6CtAMbJz1XD8ELUs1KXaTD

SlidingTabLayout 教程（视频 26-28）：https://www.youtube.com/watch?v=Fl0xMuo10yA&index=26&list=PLonJJ3BVjZW6CtAMbJz1XD8ELUs1KXaTD

Android Studio - 滑动选项卡显示在操作栏下方而不是操作栏上

Android Studio - Sliding Tabs appear below action bar instead of on action bar

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android-layout

android-studio

tabs

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