Android Fragment加载API数据

Question

在空闲时间，我正在制作一个基本的应用程序。我有一个碎片导航。主屏幕是一个活动屏幕。现在我有一个问题，我无法选择API数据需要加载的布局。我的MainActivity看起来是这样的(我认为onCreate足够了，但复制了整个类(：

package com.example.myapplication;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import com.example.myapplication.domain.Joke;
import com.example.myapplication.logic.JokesAPITask;
import com.example.myapplication.logic.JokesAdapter;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.navigation.NavigationView;
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.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.example.myapplication.databinding.ActivityMainBinding;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity implements JokesAPITask.JokeListener{
private AppBarConfiguration mAppBarConfiguration;
private ActivityMainBinding binding;
private RecyclerView recyclerview;
private JokesAdapter jokesAdapter;
private ArrayList<Joke> jokesList = new ArrayList<>();
private final String TAG = getClass().getSimpleName();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//        setContentView(R.layout.content_main);
binding = ActivityMainBinding.inflate(getLayoutInflater());
setContentView(binding.getRoot());
setSupportActionBar(binding.appBarMain.toolbar);
binding.appBarMain.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 = binding.drawerLayout;
NavigationView navigationView = binding.navView;
// 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_content_main);
NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
recyclerview = (RecyclerView) findViewById(R.id.rv_jokes_top10);
LinearLayoutManager layoutManager =
new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
recyclerview.setLayoutManager(layoutManager);
jokesAdapter = new JokesAdapter(jokesList);
recyclerview.setAdapter(jokesAdapter);
String[] params = {
"https://official-joke-api.appspot.com/random_ten"
};
new JokesAPITask(this).execute(params);
}
@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 onSupportNavigateUp() {
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
return NavigationUI.navigateUp(navController, mAppBarConfiguration)
|| super.onSupportNavigateUp();
}

@Override
public void onJokesAvailable(List<Joke> jokes) {
Log.d(TAG, "onJokesAvailable: aangeroepen");
this.jokesList.clear();
this.jokesList.addAll(jokes);
this.jokesAdapter.notifyDataSetChanged();
}
}

Answer 1

我认为您还没有实现navigationView的onItemSelectedListener。从那里加载相应的片段并从片段加载数据

binding.navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
int id = menuItem.getItemId();
Intent intent;
switch (id) {
case R.id.menu_home:
// your code goes here or you can replace fragment
break;
case R.id.menu_profile:
// your code goes here
break;
case R.id.menu_logout:
// your code goes here
break;
}
return true
}
});