android - 如何点击导航选项

Question

我的目标是通过使用导航栏，我可以使用应用程序的其他页面。我可以通过单击导航栏来更改页面并到达相应的页面。

我期待这个目标，但实际结果如下。通过使用菜单选项，我无法在导航栏的帮助下使用或移动到该页面。通过单击该选项，我无法访问相应的页面。

我没有认识到这背后的确切错误。这是导航栏，我无法单击“我的商城”或“我的订单”或“我的购物车”等选项：

这是我的代码。我怎样才能找到错误？

package com.example.mycart;

import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.view.Menu;
import android.widget.FrameLayout;
import android.widget.ImageView;

import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.navigation.NavigationView;

import androidx.annotation.NonNull;
import androidx.core.view.GravityCompat;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentTransaction;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.recyclerview.widget.RecyclerView;

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

    private AppBarConfiguration mAppBarConfiguration;

    private FrameLayout frameLayout;
    private static final int HOME_FRAGMENT = 0 ;
    private static final int CART_FRAGMENT = 1 ;
    private static final int ORDERS_FRAGMENT = 2 ;

    private static int currentFragment = -1 ;
    private NavigationView navigationView ;
    private ImageView actionBarLogo ;

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


        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        navigationView = findViewById(R.id.nav_view);
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        mAppBarConfiguration = new AppBarConfiguration.Builder(
                R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow)
                .setDrawerLayout(drawer)
                .build();
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, navController);
        navigationView.getMenu().getItem(0).setChecked(true);
        frameLayout = findViewById(R.id.main_framelayout);
        setFragment(new HomeFragment(),HOME_FRAGMENT);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.

        if(currentFragment == HOME_FRAGMENT) {
            getSupportActionBar().setDisplayShowTitleEnabled(false);
            getMenuInflater().inflate(R.menu.main,menu);
        }
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        int id=item.getItemId();
        if (id == R.id.main_search_icon){
            // todo : search
            return true;
        }
        else if (id == R.id.main_notification_icon){
            // todo : notification
            return true;
        }
        else if(id == R.id.main_cart_icon){
            gotoFragment("My Cart", new MyCartFragment(),CART_FRAGMENT);
           return true;
        }
        return super.onOptionsItemSelected(item);
    }

    private void gotoFragment(String title,Fragment fragment,int fragmentNo) {
        actionBarLogo.setVisibility(View.GONE);
        getSupportActionBar().setDisplayShowTitleEnabled(true);
        getSupportActionBar().setTitle(title);
        invalidateOptionsMenu();
        setFragment(fragment, fragmentNo);
        if (fragmentNo == CART_FRAGMENT) {
            navigationView.getMenu().getItem(3).setChecked(true);
        }
    }

    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        int id = item.getItemId();

        if(id==R.id.nav_my_mall)
        {
            actionBarLogo.setVisibility(View.VISIBLE);
            invalidateOptionsMenu();
            setFragment(new HomeFragment(),HOME_FRAGMENT);
        }
        else if(id==R.id.nav_my_orders)
        {
            gotoFragment("My Orders", new MyOrdersFragment(), ORDERS_FRAGMENT);
        }
        else if(id==R.id.nav_my_rewards)
        {

        }
        else if(id==R.id.nav_my_cart)
        {
            gotoFragment("My Cart", new MyCartFragment(),CART_FRAGMENT);
        }
        else if(id==R.id.nav_my_wishlist)
        {

        }
        else if(id==R.id.nav_my_account)
        {

        }
        else if(id==R.id.nav_sign_out)
        {

        }

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

    @Override
    public boolean onSupportNavigateUp(){
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        return NavigationUI.navigateUp(navController, mAppBarConfiguration)
                || super.onSupportNavigateUp();
    }

    private void setFragment(Fragment fragment,int fragmentNo) {
        if (fragmentNo != currentFragment) {
            currentFragment = fragmentNo;
            FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
            fragmentTransaction.setCustomAnimations(R.anim.fade_in, R.anim.fade_out);
            fragmentTransaction.replace(frameLayout.getId(), fragment);
            fragmentTransaction.commit();
        }
    }
}

标签： androidandroid-studioencodingnavigationbar

Answer 1

您需要将用户导航到 中的其他片段， onNavigationItemSelected并且我可以看到您尚未在代码中处理此问题，因此条件为空。