Android下面的代码应该修改声明＆＃34; Hello World！＆＃34;说＆＃34;今天是8月4日＆＃34;今天，说＆＃34; ERROR＆＃34;一年中的任何其他日子。但是，我得到的只是＆＃34; Hello World！＆＃34;奇怪的是，我在完全新的程序上以完全相同的方式运行代码，但没有在类FirstFragment中嵌套类CheckDate。我试图通过删除FirstFragment类来解决这个问题，但是这导致了我的MainActivity类中的错误，我用它为应用程序创建了侧边栏应用程序。有什么我可以做的来保持侧边栏，并让应用程序修改文本＆＃34; Hello World！＆＃34;它应该说什么？
FirstFragment
package com.example.gcsd.gcsdapp;
import android.app.Fragment;
import android.icu.util.Calendar;
import android.icu.util.GregorianCalendar;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.app.FragmentManager;
import android.widget.TextView;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.icu.util.GregorianCalendar;
import android.icu.util.Calendar;
public class FirstFragment extends Fragment {
View myView;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
myView = inflater.inflate(R.layout.home, container, false);
return myView;
}
public class CheckDate extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView textView = (TextView) findViewById(R.id.textView);
GregorianCalendar cal = new GregorianCalendar();
System.out.println(cal.get(Calendar.DATE)); //prints 4
System.out.println(cal.get(Calendar.MONTH) + 1); //this starts at 0, not 1. Therefore, add 1
System.out.println(cal.get(Calendar.YEAR)); //2017
if ((cal.get(Calendar.DAY_OF_MONTH) + 0 == 4) && (cal.get(Calendar.MONTH) + 1 == 8)) { //Is it the fourth of the month of 2017?
System.out.println("TODAY IS AUGUST FOURTH");
textView.setText("TODAY IS AUGUST FOURTH");
} else {
System.out.println("ERROR");
textView.setText("ERROR");
}
}
}
}
First Fragment $ CheckDate.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.gcsd.gcsdapp.FirstFragment$CheckDate">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/textView"
android:text="Hello World!"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
MainActivity
package com.example.gcsd.gcsdapp;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.FragmentManager;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.support.v4.app.FragmentManager;
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);
FloatingActionButton fab = (FloatingActionButton) 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 = (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);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
android.app.FragmentManager fragmentManager = getFragmentManager();
if (id == R.id.nav_home) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new FirstFragment())
.commit();
} else if (id == R.id.nav_events) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new SecondFragment())
.commit();
} else if (id == R.id.nav_schooltool) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new ThirdFragment())
.commit();
} else if (id == R.id.nav_lessonreminders) {
fragmentManager.beginTransaction()
.replace(R.id.content_frame
, new FourthFragment())
.commit();
} else if (id == R.id.nav_share) {
} else if (id == R.id.nav_send) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}