The essence of the problem is the following: there is a main activity, and when you try to switch to another, all components of another activity simply overlap with the main one. How can this be fixed? I attach the code:
public class MainActivity extends AppCompatActivity { private TextView mDateDisplayStart; private TextView mDateDisplayEnd; private ImageButton mPickDateStart; private ImageButton mPickDateEnd; private String[] mScreenTitles; private DrawerLayout mDrawerLayout; private ListView mDrawerList; private android.support.v4.app.ActionBarDrawerToggle mDrawerToggle; private CharSequence mDrawerTitle; private CharSequence mTitle; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mDateDisplayStart = (TextView) findViewById(R.id.dateStart); mDateDisplayEnd = (TextView) findViewById(R.id.dateEnd); mPickDateStart = (ImageButton) findViewById(R.id.showDateStartPicker); mPickDateEnd = (ImageButton) findViewById(R.id.showDateEndPicker); final Context context = this; mPickDateStart.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { MyDatePicker dlg = new MyDatePicker(context); dlg.setTextView(mDateDisplayStart); dlg.show(); } }); mPickDateEnd.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { MyDatePicker dlg = new MyDatePicker(context); dlg.setTextView(mDateDisplayEnd); dlg.show(); } }); mTitle = mDrawerTitle = getTitle(); mScreenTitles = getResources().getStringArray(R.array.screen_array); mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); mDrawerList = (ListView) findViewById(R.id.left_drawer); // Set the adapter for the list view mDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, mScreenTitles)); // Set the list's click listener mDrawerList.setOnItemClickListener(new DrawerItemClickListener()); getSupportActionBar().setDisplayHomeAsUpEnabled(true); getSupportActionBar().setHomeButtonEnabled(true); mDrawerToggle = new ActionBarDrawerToggle( this, /* host Activity */ mDrawerLayout, /* DrawerLayout object */ R.drawable.ic_drawer, /* nav drawer icon to replace 'Up' caret */ R.string.drawer_open, /* "open drawer" description */ R.string.drawer_close /* "close drawer" description */ ) { /** Called when a drawer has settled in a completely closed state. */ public void onDrawerClosed(View view) { getSupportActionBar().setTitle(mTitle); supportInvalidateOptionsMenu(); // creates call to onPrepareOptionsMenu() } /** Called when a drawer has settled in a completely open state. */ public void onDrawerOpened(View drawerView) { getSupportActionBar().setTitle(mDrawerTitle); supportInvalidateOptionsMenu(); // creates call to onPrepareOptionsMenu() } }; // Set the drawer toggle as the DrawerListener mDrawerLayout.setDrawerListener(mDrawerToggle); // Initialize the first fragment when the application first loads. if (savedInstanceState == null) { selectItem(0); } } private void updateDisplay(TextView tv, Calendar c) { tv.setText(new StringBuilder() .append(c.get(Calendar.DAY_OF_MONTH)) .append("/") .append(c.get(Calendar.MONTH) + 1) .append("/") .append(c.get(Calendar.YEAR))); } private class MyDatePicker extends DatePickerDialog { public MyDatePicker(Context context) { super( context, null, Calendar.getInstance().get(Calendar.YEAR), Calendar.getInstance().get(Calendar.MONTH), Calendar.getInstance().get(Calendar.DAY_OF_MONTH)); } // Раскомментируй, если нужен такой конструктор // public MyDatePicker(Context context, @Nullable OnDateSetListener listener, int y, int m, int d) { // super(context, listener, y, m, d); // } private final Calendar c = Calendar.getInstance(); private TextView tv = null; @Override public void onDateChanged(DatePicker view, int year, int month, int dayOfMonth) { // По мере изменения даты, обновляем Calendar: c.clear(); c.set(year, month, dayOfMonth); // Если хочешь, чтобы дата менялась по мере ввода раскомментируй //if (tv!=null) updateDisplay(tv, c); } @Override public void onClick(DialogInterface dialog, int which) { if (which == DialogInterface.BUTTON_POSITIVE && tv != null) { updateDisplay(tv, c); } super.onClick(dialog, which); } public void setTextView(TextView textView) { tv = textView; } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.main, menu); return super.onCreateOptionsMenu(menu); } @Override public boolean onPrepareOptionsMenu(Menu menu) { // If the nav drawer is open, hide action items related to the content view boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList); menu.findItem(R.id.action_search).setVisible(!drawerOpen); return super.onPrepareOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { // Pass the event to ActionBarDrawerToggle, if it returns // true, then it has handled the app icon touch event if (mDrawerToggle.onOptionsItemSelected(item)) { return true; } // Handle action buttons switch(item.getItemId()) { case R.id.action_search: // Show toast about click. Toast.makeText(this, R.string.action_search, Toast.LENGTH_SHORT).show(); return true; default: return super.onOptionsItemSelected(item); } } /* The click listener for ListView in the navigation drawer */ private class DrawerItemClickListener implements ListView.OnItemClickListener { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { selectItem(position); } } /** Swaps fragments in the main content view */ private void selectItem(int position) { // Update the main content by replacing fragments Fragment fragment = null; switch (position) { case 0: fragment = new ScreenOne(); break; case 1: fragment = new ScreenTwo(); break; case 2: fragment = new ScreenThree(); break; case 3: fragment = new ScreenFour(); default: break; } // Insert the fragment by replacing any existing fragment if (fragment != null) { FragmentManager fragmentManager = getSupportFragmentManager(); fragmentManager.beginTransaction() .replace(R.id.content_frame, fragment).commit(); // Highlight the selected item, update the title, and close the drawer mDrawerList.setItemChecked(position, true); setTitle(mScreenTitles[position]); mDrawerLayout.closeDrawer(mDrawerList); } else { // Error Log.e(this.getClass().getName(), "Error. Fragment is not created"); } } @Override public void setTitle(CharSequence title) { mTitle = title; getSupportActionBar().setTitle(mTitle); } /** * When using the ActionBarDrawerToggle, you must call it during * onPostCreate() and onConfigurationChanged()... */ @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); // Sync the toggle state after onRestoreInstanceState has occurred. mDrawerToggle.syncState(); } @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); // Pass any configuration change to the drawer toggles mDrawerToggle.onConfigurationChanged(newConfig); } public void Bronirovat(View view) { Intent nextActivity = new Intent(this, Bronirovat.class); startActivity(nextActivity); } } 
