android - Android NavigationView设置默认 fragment

我正在使用新的NavigationView，因为我已将项目升级到API 23，效果很好，但是如何设置默认片段？打开应用程序的片段。这是我的代码，感谢您的建议。

public class MainActivity extends AppCompatActivity {

    private Toolbar toolbar;
    private NavigationView navigationView;
    private DrawerLayout drawerLayout;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Initializing Toolbar and setting it as the actionbar
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        //Initializing NavigationView
        navigationView = (NavigationView) findViewById(R.id.navigation_view);

        //Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
        navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {

            // This method will trigger on item Click of navigation menu
            @Override
            public boolean onNavigationItemSelected(MenuItem menuItem) {


                //Checking if the item is in checked state or not, if not make it in checked state
                if(menuItem.isChecked()) menuItem.setChecked(false);
                else menuItem.setChecked(true);

                //Closing drawer on item click
                drawerLayout.closeDrawers();

                //Check to see which item was being clicked and perform appropriate action
                switch (menuItem.getItemId()){
    //Replacing the main content with ContentFragment Which is our Inbox View;
                    case R.id.inbox:
                        Toast.makeText(getApplicationContext(),"Inbox Selected",Toast.LENGTH_SHORT).show();
                        ContentFragment fragment = new ContentFragment();
                        android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
                        fragmentTransaction.replace(R.id.frame,fragment);
                        fragmentTransaction.commit();
                        return true;

                    case R.id.starred:
                        Toast.makeText(getApplicationContext(),"Stared Selected",Toast.LENGTH_SHORT).show();
                        return true;
                    default:
                        Toast.makeText(getApplicationContext(),"Somethings Wrong",Toast.LENGTH_SHORT).show();
                        return true;
                }
            }
        });

        // Initializing Drawer Layout and ActionBarToggle
        drawerLayout = (DrawerLayout) findViewById(R.id.drawer);
        ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.openDrawer, R.string.closeDrawer){

            @Override
            public void onDrawerClosed(View drawerView) {
                // Code here will be triggered once the drawer closes as we dont want anything to happen so we leave this blank
                super.onDrawerClosed(drawerView);
            }

            @Override
            public void onDrawerOpened(View drawerView) {
                // Code here will be triggered once the drawer open as we dont want anything to happen so we leave this blank

                super.onDrawerOpened(drawerView);
            }
        };

        //Setting the actionbarToggle to drawer layout
        drawerLayout.setDrawerListener(actionBarDrawerToggle);

        //calling sync state is necessay or else your hamburger icon wont show up
        actionBarDrawerToggle.syncState();

    }


}

最佳答案

您可以在layout.activity_main中添加片段或

在activity_main布局中添加一些容器，例如FrameLayout，并在

private Fragment currentFragment;

    @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.search_group_activity);
            if (savedInstanceState == null){
                currentFragment = new DefaultFragment();
                getFragmentManager().beginTransaction()
                        .add(R.id.frame, currentFragment).commit();
            }
    }

在听众中

                 case R.id.inbox:
                    Toast.makeText(getApplicationContext(),"Inbox Selected",Toast.LENGTH_SHORT).show();
                    currentFragment = new ContentFragment();
                    android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
                    fragmentTransaction.replace(R.id.frame, currentFragment);
                    fragmentTransaction.commit();
                    return true;

关于android - Android NavigationView设置默认 fragment ，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/34601236/