Question

我正在设计一个Android应用程序并创建了一个活动，当我使用gridview时，该活动无法扩展到片段。问题是，当我尝试导航到导航抽屉内的活动时，它不起作用。有没有办法在仍然使用gridview时扩展到片段？

活动我正试图导航到

public class GalleryActivity extends FragmentActivity {
private GridView gridView;
private GridViewAdapter gridAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_gallery);


    gridView = (GridView) findViewById(R.id.gridView);
    gridAdapter = new GridViewAdapter(this, R.layout.grid_item_layout, getData());
    gridView.setAdapter(gridAdapter);

    gridView.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            ImageItem item = (ImageItem) parent.getItemAtPosition(position);

            //Create intent
            Intent intent = new Intent(GalleryActivity.this, DetailsActivity.class);
            intent.putExtra("title", item.getTitle());
            intent.putExtra("image", item.getImage());

            //Start details activity
            startActivity(intent);
        }
    });
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_gallery, container, false);
}

/**
 * Prepare some dummy data for gridview
 */
private ArrayList<ImageItem> getData() {
    final ArrayList<ImageItem> imageItems = new ArrayList<>();
    TypedArray imgs = getResources().obtainTypedArray(R.array.image_ids);
    for (int i = 0; i < imgs.length(); i++) {
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), imgs.getResourceId(i, -1));
        imageItems.add(new ImageItem(bitmap, "Image#" + i));
    }
    return imageItems;
}


}

以下是导航抽屉的代码，我正在尝试导航到GalleryActivity

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);



    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}


@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);


}

//Function to switch screens by passing the navigation ID
private void displaySelectedScreen(int id) {
    Fragment fragment = null;
    switch (id) {
        case R.id.nav_Home:
            fragment = new HomeActivity();
            break;
        case R.id.nav_About:
            fragment = new AboutActivity();
            break;
        case R.id.nav_Gallery:
            fragment = new GalleryActivity();
            break;
        case R.id.nav_locationMap:
            fragment = new LocationActivity();
            break;
        case R.id.nav_products:
            fragment = new ProductsActivity();
            break;
    }
    if (fragment != null) {
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.content_main, fragment);
        ft.commit();

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
    }
}

@SuppressWarnings("StatementWithEmptyBody")
@Override

public boolean onNavigationItemSelected(MenuItem item) {
    displaySelectedScreen(item.getItemId());
    return true;
}

}

Answer 1

请参阅Android switch Fragments in the new design support navigation drawer

您需要在setNavigationItemSelectedListener

上设置navigationView

Answer 2

你应该将片段活动转换为片段。就像使用这段代码一样..

public class GalleryActivity extends Fragment {
private GridView gridView;
private GridViewAdapter gridAdapter;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_gallery, null);
    gridView = (GridView) view.findViewById(R.id.gridView);
    gridAdapter = new GridViewAdapter(this, R.layout.grid_item_layout, getData());
    gridView.setAdapter(gridAdapter);

    gridView.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            ImageItem item = (ImageItem) parent.getItemAtPosition(position);

            //Create intent
            Intent intent = new Intent(GalleryActivity.this, DetailsActivity.class);
            intent.putExtra("title", item.getTitle());
            intent.putExtra("image", item.getImage());

            //Start details activity
            startActivity(intent);
        }
    });
}

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_gallery, container, false);
}
}

Answer 3

首先，您是如何想象通过传递活动类型来创建片段的？

Fragment fragment = null;
switch (id) {
    case R.id.nav_Home:
        fragment = new HomeActivity();
        break;

通过android-studio中的导航抽屉调用活动

3 个答案: