While building my app I noticed that my app force closes when I import any Java util in my MainActivity(.java).
The original one is this one:
package com.ivancristina.navigazione;
import android.content.Context;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
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.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("");
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();
if (id == R.id.nav_formule) {
LinearLayout mainLayout = (LinearLayout) findViewById(R.id. main_container);
LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.content_formule, null);
mainLayout.removeAllViews();
mainLayout.addView(layout);
} else if (id == R.id.nav_esempi) {
LinearLayout mainLayout = (LinearLayout) findViewById(R.id. main_container);
LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.content_esempi, null);
mainLayout.removeAllViews();
mainLayout.addView(layout);
} else if (id == R.id.nav_home) {
LinearLayout mainLayout = (LinearLayout) findViewById(R.id. main_container);
LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.content_main, null);
mainLayout.removeAllViews();
mainLayout.addView(layout);
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}
while the that one with java is this one:
package com.ivancristina.navigazione;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
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.util.SparseBooleanArray;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.Toast;
import java.util.*;
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
private ImageView logo;
private Button github;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initialize();
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("");
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);
}
private void initialize() {
logo = (ImageView) findViewById(R.id.logo);
github = (Button) findViewById(R.id.github);
logo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View _v) {
showMessage("OnClick");
}
});
github.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View _v) {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.github.com/ivancristina")));
}
});
}
// created automatically
private void showMessage(String _s) {
Toast.makeText(getApplicationContext(), _s, Toast.LENGTH_SHORT).show();
}
private int getRandom(int _minValue ,int _maxValue){
Random random = new Random();
return random.nextInt(_maxValue - _minValue + 1) + _minValue;
}
public ArrayList<Double> getCheckedItemPositionsToArray(ListView _list) {
ArrayList<Double> _result = new ArrayList<Double>();
SparseBooleanArray _arr = _list.getCheckedItemPositions();
for (int _iIdx = 0; _iIdx < _arr.size(); _iIdx++) {
if (_arr.valueAt(_iIdx))
_result.add((double)_arr.keyAt(_iIdx));
}
return _result;
}
@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();
if (id == R.id.nav_formule) {
LinearLayout mainLayout = (LinearLayout) findViewById(R.id. main_container);
LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.content_formule, null);
mainLayout.removeAllViews();
mainLayout.addView(layout);
} else if (id == R.id.nav_esempi) {
LinearLayout mainLayout = (LinearLayout) findViewById(R.id. main_container);
LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.content_esempi, null);
mainLayout.removeAllViews();
mainLayout.addView(layout);
} else if (id == R.id.nav_home) {
LinearLayout mainLayout = (LinearLayout) findViewById(R.id. main_container);
LayoutInflater inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.content_main, null);
mainLayout.removeAllViews();
mainLayout.addView(layout);
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}
I'm sure I made something wrong with some activity, anyway if anyone would like to get a look to the rest of the project, here there are my content_main and content_formule , which as I said work fine without Java, but in this way are useless.
(Posted on behalf of the OP) .
The mistake was mine.
I put initialize();
right after super.onCreate(savedInstanceState);
. Moving it right before
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
solved my problem.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.