Android 筆記 - Tablayout & ViewPager2 or ViewPager

 點擊 TabLayout 的 TabItem，自動切換 ViewPager2 或 ViewPager 的頁面

ViewPager2 的搭配使用方法

用法如下 (另附上 ViewPager2用法連結)

TabLayout tl = findViewById(R.id.你的TabLayout物件ID);
ViewPager2 vp = findViewById(R.id.你的ViewPager2物件ID);
vp_top.setAdapter(new ViewPager2Adapter(this));
new TabLayoutMediator(tl, vp,
        (tab, position) -> tab.setText("Title " + (position + 1))
).attach();

ViewPager 的搭配使用方法

用法如下（感覺很簡單，但我沒試過這個XD。但...有新的還用舊的物件??）

TabLayout tl = findViewById(R.id.你的TabLayout物件ID);
ViewPager vp = findViewById(R.id.你的ViewPager2物件ID);
tl_top.setupWithViewPager(vp);

我的用法 - MyTabLayout.java

public class MyTabLayout {
    static int[] stringID, iconID, layoutID;
    public int size;
    public TabLayout tl;
    public ViewPager2 vp;

    MyTabLayout(Activity activity, Context context, FragmentActivity fa, int tabLayoutID, int viewPagerID, int[] _stringID, int[] _iconID, int[] _layoutID) {
        stringID = _stringID;
        iconID = _iconID;
        layoutID = _layoutID;
        if(stringID != null)
            size = stringID.length;
        if(iconID != null)
            size = iconID.length;

        tl = activity.findViewById(tabLayoutID);
        vp = activity.findViewById(viewPagerID);
        vp.setAdapter(new ViewPager2Adapter(fa));
        new TabLayoutMediator(tl, vp, (tab, position) -> {
            if(stringID != null && stringID[position] != 0)
                tab.setText(context.getString(stringID[position]));
            if(iconID != null && iconID[position] != 0)
                tab.setIcon(iconID[position]);

            // 也可以用自訂的 View，並在這改內容
//            View v = LayoutInflater.from(context).inflate(R.layout.你的layoutXML, tab.view, false);
//            ImageView iv = v.findViewById(R.id.iv);
//            iv.setImageResource(iconID[position]);
//            TextView tv = v.findViewById(R.id.tv);
//            tv.setText(context.getString(stringID[position]));
//            tab.setCustomView(v);
        }).attach();
    }

    public static class ViewPager2Fragment extends Fragment {
        int pos;
        public ViewPager2Fragment(int position) {
            pos = position;
        }
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            return inflater.inflate(layoutID[pos], container, false);
        }
    }
    private class ViewPager2Adapter extends FragmentStateAdapter {
        public ViewPager2Adapter(FragmentActivity fa) {
            super(fa);
        }
        @Override
        public Fragment createFragment(int position) {
            return new ViewPager2Fragment(position);
        }
        @Override
        public int getItemCount() {
            return size;
        }
    }
}