如何以编程方式切换标签SlidingTabStrip和ViewPager

Question

我无法以编程方式切换SlidingTabStrip标签。

我正在使用SlidingTabStrip与viewpager结合使用。

我使用

mSlidingTabs.setViewPager(mPager); 
mViewPager.setCurrentItem(position); 

这使viewpager到所选择的屏幕，并且选择相应的选项卡。 但是，如果相应的选项卡是不是在屏幕的观看范围.. 它没有被滚动到视图

这是我SlidingTabStrip.java

public class SlidingTabLayout extends HorizontalScrollView { 
    /** 
    * Allows complete control over the colors drawn in the tab layout. Set with 
    * {@link #setCustomTabColorizer(TabColorizer)}. 
    */ 
    public interface TabColorizer { 

     /** 
     * @return return the color of the indicator used when {@code position} is selected. 
     */ 
     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); 
    } 

    /** 
    * Set the custom {@link TabColorizer} to be used. 
    * <p/> 
    * If you only require simple custmisation then you can use 
    * {@link #setSelectedIndicatorColors(int...)} to achieve 
    * similar effects. 
    */ 
    public void setCustomTabColorizer(TabColorizer tabColorizer) { 
     mTabStrip.setCustomTabColorizer(tabColorizer); 
    } 

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

    /** 
    * Sets the colors to be used for indicating the selected tab. These colors are treated as a 
    * circular array. Providing one color will mean that all tabs are indicated with the same 
    * color. 
    */ 
    public void setSelectedIndicatorColors(int... colors) { 
     mTabStrip.setSelectedIndicatorColors(colors); 
    } 

    /** 
    * Set the {@link android.support.v4.view.ViewPager.OnPageChangeListener}. When using {@link SlidingTabLayout} you are 
    * required to set any {@link android.support.v4.view.ViewPager.OnPageChangeListener} through this method. This is so 
    * that the layout can update it's scroll position correctly. 
    * 
    * @see android.support.v4.view.ViewPager#setOnPageChangeListener(android.support.v4.view.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 android.widget.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 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); 
     } 
    } 

    public 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; 
      } 
      Timber.i("Scroll "+targetScrollX); 
      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 count = mTabStrip.getChildCount(); 
//   for (int i = 0; i < count; i++) { 
//    if (position != i) { 
//     ((TextView) mTabStrip.getChildAt(i)).setTextColor(getContext().getResources() 
//       .getColor(R.color.app_text_color_disabled)); 
//    } else { 
//     ((TextView) selectedTitle).setTextColor(getContext().getResources().getColor 
//       (R.color.app_text_color)); 
//    } 
//   } 
      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 OnClickListener { 
     @Override 
     public void onClick(View v) { 
      for (int i = 0; i < mTabStrip.getChildCount(); i++) { 
       if (v == mTabStrip.getChildAt(i)) { 
        mViewPager.setCurrentItem(i); 
        return; 
       } 
      } 
     } 
    } 

} 

Answer 1

我有点找到了解决方法这不是一个清晰的解决方案 但我要做的就是调用

ViewTreeObserver vto = mainContainer.getViewTreeObserver(); 
     vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() { 

      @Override 
      public void onGlobalLayout() { 
       try { 
        mSlidingTabs.scrollToTab(tabPosition,0); 
       } catch (NullPointerException e) { 
        e.printStackTrace(); 
       } 
      } 

     }); 

更好的解决方案是值得欢迎的。