Android滑动选项卡布局不工作

嘿，我是android开发的新手。我想在我的应用程序中创建滑动选项卡布局。但是当我运行我的应用程序时。它停止了，并说不幸的是，应用程序已经停止工作。这是我想展示的代码

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

import tabs.SlidingTablayout;


public class NewsFeed extends ActionBarActivity {
private Toolbar toolbar;
NavigationDrawer drawerFragment;
private ViewPager mPager;
private SlidingTablayout mTabs;

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



    drawerFragment=new NavigationDrawer();
    getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
   drawerFragment.setUp((DrawerLayout) findViewById(R.id.drawer_layout), toolbar);

    mPager=(ViewPager) findViewById(R.id.pager);
    mPager.setAdapter(new myPagerAdapter(getSupportFragmentManager()));
    mTabs=(SlidingTablayout) findViewById(R.id.tabs);
    mTabs.setViewPager(mPager);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater menuInflater= getMenuInflater();
    menuInflater.inflate(R.menu.activity_actionbar, menu);
    return super.onCreateOptionsMenu(menu);
}

@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.search_id) {
        Toast msg = Toast.makeText(NewsFeed.this, "search selected", Toast.LENGTH_SHORT);
        msg.show();

        return true;
    }
    if (id==R.id.info_id){
        Toast msg = Toast.makeText(NewsFeed.this, "info selected", Toast.LENGTH_SHORT);
        msg.show();
        return true;
    }

    return super.onOptionsItemSelected(item);
}
class myPagerAdapter extends FragmentPagerAdapter{

    String[] tabs;
    public myPagerAdapter(FragmentManager fm) {
        super(fm);
        tabs=getResources().getStringArray(R.array.tabs);
    }

    @Override
    public Fragment getItem(int position) {
        MyFragment myFragment=MyFragment.getInstance(position);

        return myFragment;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return tabs[position];
    }

    @Override
    public int getCount() {
        return 3;
    }
}
public static class MyFragment extends Fragment{
    private TextView textView;
    public static MyFragment getInstance(int position){
        MyFragment myFragment=new MyFragment();
        Bundle args=new Bundle();
        args.putInt("position",position);
        myFragment.setArguments(args);
        return myFragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View layout=inflater.inflate(R.layout.fragment_my, container, false);
        textView=(TextView) layout.findViewById(R.id.position);
        Bundle bundle=getArguments();
        if(bundle!=null){
            textView.setText("The Page currently Selecte"+bundle.getInt("position"));
        }

        return layout;
    }
}

}

这是我的slide tablayout.java类

package 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);


    setHorizontalScrollBarEnabled(false);

    setFillViewport(true);

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

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


public void setCustomTabColorizer(TabColorizer tabColorizer) {
    mTabStrip.setCustomTabColorizer(tabColorizer);
}

public void setDistributeEvenly(boolean distributeEvenly) {
    mDistributeEvenly = distributeEvenly;
}


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

public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mViewPagerPageChangeListener = listener;
}


public void setCustomTabView(int layoutResId, int textViewId) {
    mTabViewLayoutId = layoutResId;
    mTabViewTextViewId = textViewId;
}


public void setViewPager(ViewPager viewPager) {
    mTabStrip.removeAllViews();

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

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) {

            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) {

            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;
            }
        }
    }
}

请帮帮我

mTabs=(SlidingTablayout) findViewById(R.id.tabs);
mTabs.setViewPager(mPager);

---

你的MTAB正在抛出NPE。请重新检查您的SlidingTableout id一次，或者在xml中使用SlidingTableout的完全限定名，您在xml中定义它。

NewsFeed.java中的第44行是什么？您是否为此使用eclipse？不，我正在使用android studio@RobertConley。NewsFeed.java中的第44行出现空指针异常。您能告诉我吗那是哪一行..在那一行我为我的VeiwPage添加了一个适配器。下面定义的fragmentManager作为参数@Lal传递

02-29 22:37:41.472 6653-6653/com.example.mubbasher.howdy_sendgreetings D/dalvikvm: Late-enabling CheckJNI
02-29 22:37:41.752 6653-6653/com.example.mubbasher.howdy_sendgreetings I/dalvikvm: Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.internal.widget.TintTypedArray.getChangingConfigurations
02-29 22:37:41.752 6653-6653/com.example.mubbasher.howdy_sendgreetings W/dalvikvm: VFY: unable to resolve virtual method 373: Landroid/content/res/TypedArray;.getChangingConfigurations ()I
02-29 22:37:41.752 6653-6653/com.example.mubbasher.howdy_sendgreetings D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
02-29 22:37:41.752 6653-6653/com.example.mubbasher.howdy_sendgreetings I/dalvikvm: Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.internal.widget.TintTypedArray.getType
02-29 22:37:41.752 6653-6653/com.example.mubbasher.howdy_sendgreetings W/dalvikvm: VFY: unable to resolve virtual method 395: Landroid/content/res/TypedArray;.getType (I)I
02-29 22:37:41.752 6653-6653/com.example.mubbasher.howdy_sendgreetings D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
02-29 22:37:41.862 6653-6653/com.example.mubbasher.howdy_sendgreetings D/AndroidRuntime: Shutting down VM
02-29 22:37:41.862 6653-6653/com.example.mubbasher.howdy_sendgreetings W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x41754c08)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime: FATAL EXCEPTION: main
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime: Process: com.example.mubbasher.howdy_sendgreetings, PID: 6653
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mubbasher.howdy_sendgreetings/com.example.mubbasher.howdy_sendgreetings.NewsFeed}: java.lang.NullPointerException
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2436)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2498)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.access$900(ActivityThread.java:179)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1324)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:146)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5641)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:515)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1288)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1104)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:  Caused by: java.lang.NullPointerException
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at com.example.mubbasher.howdy_sendgreetings.NewsFeed.onCreate(NewsFeed.java:44)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:5484)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2400)
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2498) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.access$900(ActivityThread.java:179) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1324) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:146) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5641) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:515) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1288) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1104) 
02-29 22:37:41.872 6653-6653/com.example.mubbasher.howdy_sendgreetings E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method) 

mTabs=(SlidingTablayout) findViewById(R.id.tabs);
mTabs.setViewPager(mPager);