Question

我想用activity

开始fragments

 Intent intent = new Intent(NewMealActivity.this, MainActivity.class);
            intent.putExtra("id", 1);
            startActivity(intent);

MainActivity包括三个fragments（Frag1，Frag2，Frag3）。我想打开Frag3，但打开Frag1

这是我的MainActivity，有三个标签

public class MainActivity extends FragmentActivity {

private String txtFragmentMyData;
private String txtFragmentProductList;
private String txtFragmentCalorieCalculator;
private TabLayout tabLayout;
private  long tabId;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    txtFragmentMyData = getString(R.string.txt_fragment_my_data);
    txtFragmentProductList = getString(R.string.txt_fragment_product_list);
    txtFragmentCalorieCalculator = getString(R.string.txt_fragment_calorie_calculator);

    tabLayout = (TabLayout) findViewById(R.id.tab_layout);

    tabLayout.addTab(tabLayout.newTab().setText(txtFragmentMyData));
    tabLayout.addTab(tabLayout.newTab().setText(txtFragmentProductList));
    tabLayout.addTab(tabLayout.newTab().setText(txtFragmentCalorieCalculator));

    tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

    final ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
    final ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager(), tabLayout.getTabCount());
    viewPager.setAdapter(adapter);
    Bundle extras = getIntent().getExtras();
    if (extras != null) {
        tabId = extras.getLong("id");
    }
    if (tabId > 0){
        viewPager.setCurrentItem(2);
    } else {
        viewPager.setCurrentItem(0);
    }
    viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
    tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            viewPager.setCurrentItem(tab.getPosition());
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

}

我想，在第一次开始时会打开第一个标签，但是如果我点击其他活动中的按钮会打开第三个标签

用片段开始活动

0 个答案: