如何以编程方式调用ViewPagerOnTabSelectedListener？

Question

我想改变我的TabLayout中的选项卡图标的颜色，实际上我使用addOnTabSelectedListener来实现这一点，但这只适用于当我在选项卡之间滑动时。所以我希望第一个选项卡的图标颜色与更改选项卡时的颜色相同。

我试过viewPager.setCurrentItem（），但这只适用于传递的索引不同于0（第一个标签）的情况。

那么，如何以编程方式调用ViewPagerOnTabSelectedListener？

这是我的代码：

tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager) { 
     @Override 
     public void onTabSelected(TabLayout.Tab tab){ 
      super.onTabReselected(tab); 
      int tabIconColor = ContextCompat.getColor(MainActivity.this,R.color.prehipertension); 
      tab.getIcon().setColorFilter(tabIconColor, PorterDuff.Mode.SRC_IN); 
     } 

     @Override 
     public void onTabUnselected(TabLayout.Tab tab){ 
      super.onTabUnselected(tab); 
      int tabIconColor = ContextCompat.getColor(MainActivity.this,R.color.blancoTransparencia); 
      tab.getIcon().setColorFilter(tabIconColor, PorterDuff.Mode.SRC_IN); 
     } 

     @Override 
     public void onTabReselected(TabLayout.Tab tab) { 
      int tabIconColor = ContextCompat.getColor(MainActivity.this,R.color.blanco); 
      tab.getIcon().setColorFilter(tabIconColor, PorterDuff.Mode.SRC_IN); 
     } 
    }); 

    viewPager.setCurrentItem(0); 

这是当拳头时间运行它的应用程序。

当滑动到第二个选项卡（并返回第一个选项卡）时，图标颜色会正确更改。

Answer 1

我不知道我能正确或不理解你的问题，但我用寻呼机查看工作和处理它通过该算法的过程。 （检查它可能是你找到你想要的）。

1-首先确定你的标签。

private void createTabIcons(){ 
    // i get custom tab view. 
    View profileTab = LayoutInflater.from(this) 
      .inflate(R.layout.custom_tab,null); 
    // set it's views such as its text and icon 
    ViewAppHolder.CustomTabViewHolder customTabProfileViewHolder = 
      new ViewAppHolder.CustomTabViewHolder(profileTab); 
    // set properties of icon ... note this is my main tab so i set 'color.active' 
    customTabProfileViewHolder.TAB_IMAGE_VIEW 
      .setImageDrawable(getDrawable(R.drawable.ic_person_black_24dp)); 
    customTabProfileViewHolder.TAB_IMAGE_VIEW 
      .setColorFilter(ContextCompat.getColor(this,R.color.active_tab)); 

    tabLayout.getTabAt(Constants.USER_PROFILE_TAB).setCustomView(profileTab); 
    // it's the next tab by the same previous steps 
    View friendsTab = LayoutInflater.from(this) 
      .inflate(R.layout.custom_tab,null); 

    ViewAppHolder.CustomTabViewHolder customTabFriendsViewHolder = 
      new ViewAppHolder.CustomTabViewHolder(friendsTab); 
    // the diff is here .. i set the color of icon 'color.non_active' 
    customTabFriendsViewHolder.TAB_IMAGE_VIEW 
      .setImageDrawable(getDrawable(R.drawable.ic_group_black_24dp)); 
    customTabFriendsViewHolder.TAB_IMAGE_VIEW 
      .setColorFilter(ContextCompat.getColor(this,R.color.non_active_tab)); 

/// .... and remain tabs also have the same thing with color non_active. 

2 - 然后在这两个onTabSelected和onTabUnselected我只是调用方法称为setCurrentTab()和它的实现是

private void setCurrentTab() { 
    if (tabLayout != null) { 
     int currentPosition = tabLayout.getSelectedTabPosition(); 
     int unSelectedTabs = currentPosition; 

     do { 
      unSelectedTabs = (unSelectedTabs + 1) % 4; 

      Log.e("un selected ", String.valueOf(unSelectedTabs)); 
      Log.e("un selected ", String.valueOf(currentPosition)); 

      ViewAppHolder.CustomTabViewHolder customTabViewHolder = 
        new ViewAppHolder.CustomTabViewHolder(
          tabLayout.getTabAt(unSelectedTabs).getCustomView() 
        ); 


      if (unSelectedTabs != currentPosition) { 
       customTabViewHolder.TAB_IMAGE_VIEW 
         .setColorFilter(ContextCompat.getColor(this, R.color.non_active_tab)); 
      } else { 
       customTabViewHolder.TAB_IMAGE_VIEW 
         .setColorFilter(ContextCompat.getColor(this, R.color.active_tab)); 
      } 

     } while (unSelectedTabs != currentPosition); 
    } 
}