Android 如何获取导航抽屉中的项目以更改视图

How to get items in Navigation Drawer to change view

提问by user3078818

I want to make an simple app with a Navigation Drawer, which can open other views (News, Information, Gallery, Contact etc). So I opened up the latest Android Studio, made a new project that is compatible with API8>API19, to get maximum reach.

我想制作一个带有导航抽屉的简单应用程序，它可以打开其他视图（新闻、信息、图库、联系人等）。所以我打开了最新的Android Studio，做了一个兼容API8>API19的新项目，以获得最大的覆盖范围。

I chose the preset Navigation Drawer and clicked finish. I have figured out to change the names of the items in the Navigation Drawer, but how do I get these items to redirect to a new view?

我选择了预设的导航抽屉并单击完成。我已经想出更改导航抽屉中项目的名称，但是如何让这些项目重定向到新视图？

I have tried implementing the setOnItemClickListener into the MainActivity as the Navigation Drawer site says on http://developer.android.com. But I can't seem to figure out how it all ties together, and it wont work.

我已经尝试将 setOnItemClickListener 实施到 MainActivity 中，正如导航抽屉网站在http://developer.android.com上所说的那样。但我似乎无法弄清楚这一切是如何联系在一起的，而且它行不通。

tl;dr:I need help with making the items in the Navigation Drawer launch a new view/fragment, and probably an explanation on how it all works.

tl; dr：我需要帮助让导航抽屉中的项目启动一个新的视图/片段，并且可能是关于它是如何工作的解释。

Here is the app project (Android Studio) https://www.dropbox.com/s/qfz9oul62dzt3rr/NTI_SHOWCASE.zip

这是应用程序项目 (Android Studio) https://www.dropbox.com/s/qfz9oul62dzt3rr/NTI_SHOWCASE.zip

MainActivity.java

主活动.java

package com.christianarne.ntishowcase;

import android.app.Activity;
import android.content.Intent;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
import android.text.Html;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.widget.DrawerLayout;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity
    implements NavigationDrawerFragment.NavigationDrawerCallbacks {


private static final int SETTINGS_RESULT = 1;

/**
 * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
 */
private NavigationDrawerFragment mNavigationDrawerFragment;

/**
 * Used to store the last screen title. For use in {@link #restoreActionBar()}.
 */
private CharSequence mTitle;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ActionBar actionBar = getSupportActionBar();
    actionBar.setBackgroundDrawable(new ColorDrawable(Color.rgb(0, 153, 204))); // set your desired color


    mNavigationDrawerFragment = (NavigationDrawerFragment)
            getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
    mTitle = getTitle();

    // Set up the drawer.
    mNavigationDrawerFragment.setUp(
            R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));
}


@Override
public void onNavigationDrawerItemSelected(int position) {
    // update the main content by replacing fragments
    FragmentManager fragmentManager = getSupportFragmentManager();
    fragmentManager.beginTransaction()
            .replace(R.id.container, PlaceholderFragment.newInstance(position + 1))
            .commit();
}

public void onSectionAttached(int number) {
    switch (number) {
        case 1:
            mTitle = getString(R.string.title_section1);
            break;
        case 2:
            mTitle = getString(R.string.title_section2);
            break;
        case 3:
            mTitle = getString(R.string.title_section3);
            break;
    }
}

public void restoreActionBar() {
    ActionBar actionBar = getSupportActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);


    actionBar.setTitle(mTitle);

}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    if (!mNavigationDrawerFragment.isDrawerOpen()) {
        // Only show items in the action bar relevant to this screen
        // if the drawer is not showing. Otherwise, let the drawer
        // decide what to show in the action bar.
        getMenuInflater().inflate(R.menu.main, menu);
        restoreActionBar();
        return true;
    }
    return super.onCreateOptionsMenu(menu);
}

@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();
    if (id == R.id.action_settings) {
        Intent intent = new Intent(this, SettingsActivity.class);
        startActivity(intent);


        return true;
    }
    if (id == R.id.action_example) {
        Intent intent_g = new Intent(this, Guide.class);
        startActivity(intent_g);
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        TextView textView = (TextView) rootView.findViewById(R.id.section_label);
        textView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
        return rootView;
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        ((MainActivity) activity).onSectionAttached(
                getArguments().getInt(ARG_SECTION_NUMBER));
    }
}

}

NavigationDrawerFragment.java

NavigationDrawerFragment.java

public class NavigationDrawerFragment extends Fragment {

/**
 * Remember the position of the selected item.
 */
private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";

/**
 * Per the design guidelines, you should show the drawer on launch until the user manually
 * expands it. This shared preference tracks this.
 */
private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";

/**
 * A pointer to the current callbacks instance (the Activity).
 */
private NavigationDrawerCallbacks mCallbacks;

/**
 * Helper component that ties the action bar to the navigation drawer.
 */
private ActionBarDrawerToggle mDrawerToggle;

private DrawerLayout mDrawerLayout;
private ListView mDrawerListView;
private View mFragmentContainerView;

private int mCurrentSelectedPosition = 0;
private boolean mFromSavedInstanceState;
private boolean mUserLearnedDrawer;

public NavigationDrawerFragment() {
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Read in the flag indicating whether or not the user has demonstrated awareness of the
    // drawer. See PREF_USER_LEARNED_DRAWER for details.
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
    mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);

    if (savedInstanceState != null) {
        mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
        mFromSavedInstanceState = true;
    }

    // Select either the default item (0) or the last selected item.
    selectItem(mCurrentSelectedPosition);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    // Indicate that this fragment would like to influence the set of actions in the action bar.
    setHasOptionsMenu(true);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    mDrawerListView = (ListView) inflater.inflate(
            R.layout.fragment_navigation_drawer, container, false);
    mDrawerListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectItem(position);
        }
    });
    mDrawerListView.setAdapter(new ArrayAdapter<String>(
            getActionBar().getThemedContext(),
            android.R.layout.simple_list_item_1,
            android.R.id.text1,
            new String[]{
                    getString(R.string.title_section1),
                    getString(R.string.title_section2),
                    getString(R.string.title_section3),
            }));
    mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
    return mDrawerListView;
}

public boolean isDrawerOpen() {
    return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
}

/**
 * Users of this fragment must call this method to set up the navigation drawer interactions.
 *
 * @param fragmentId   The android:id of this fragment in its activity's layout.
 * @param drawerLayout The DrawerLayout containing this fragment's UI.
 */
public void setUp(int fragmentId, DrawerLayout drawerLayout) {
    mFragmentContainerView = getActivity().findViewById(fragmentId);
    mDrawerLayout = drawerLayout;

    // set a custom shadow that overlays the main content when the drawer opens
    mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
    // set up the drawer's list view with items and click listener

    ActionBar actionBar = getActionBar();
    actionBar.setDisplayHomeAsUpEnabled(true);
    actionBar.setHomeButtonEnabled(true);

    // ActionBarDrawerToggle ties together the the proper interactions
    // between the navigation drawer and the action bar app icon.
    mDrawerToggle = new ActionBarDrawerToggle(
            getActivity(),                    /* host Activity */
            mDrawerLayout,                    /* DrawerLayout object */
            R.drawable.ic_drawer,             /* nav drawer image to replace 'Up' caret */
            R.string.navigation_drawer_open,  /* "open drawer" description for accessibility */
            R.string.navigation_drawer_close  /* "close drawer" description for accessibility */
    ) {
        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
            if (!isAdded()) {
                return;
            }

            getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
        }

        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
            if (!isAdded()) {
                return;
            }

            if (!mUserLearnedDrawer) {
                // The user manually opened the drawer; store this flag to prevent auto-showing
                // the navigation drawer automatically in the future.
                mUserLearnedDrawer = true;
                SharedPreferences sp = PreferenceManager
                        .getDefaultSharedPreferences(getActivity());
                sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).commit();
            }

            getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
        }
    };

    // If the user hasn't 'learned' about the drawer, open it to introduce them to the drawer,
    // per the navigation drawer design guidelines.
    if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
        mDrawerLayout.openDrawer(mFragmentContainerView);
    }

    // Defer code dependent on restoration of previous instance state.
    mDrawerLayout.post(new Runnable() {
        @Override
        public void run() {
            mDrawerToggle.syncState();
        }
    });

    mDrawerLayout.setDrawerListener(mDrawerToggle);
}

private void selectItem(int position) {
    mCurrentSelectedPosition = position;
    if (mDrawerListView != null) {
        mDrawerListView.setItemChecked(position, true);
    }
    if (mDrawerLayout != null) {
        mDrawerLayout.closeDrawer(mFragmentContainerView);
    }
    if (mCallbacks != null) {
        mCallbacks.onNavigationDrawerItemSelected(position);
    }
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
        mCallbacks = (NavigationDrawerCallbacks) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mCallbacks = null;
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    // Forward the new configuration the drawer toggle component.
    mDrawerToggle.onConfigurationChanged(newConfig);
}

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    // If the drawer is open, show the global app actions in the action bar. See also
    // showGlobalContextActionBar, which controls the top-left area of the action bar.
    if (mDrawerLayout != null && isDrawerOpen()) {
        inflater.inflate(R.menu.global, menu);
        showGlobalContextActionBar();
    }
    super.onCreateOptionsMenu(menu, inflater);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if (mDrawerToggle.onOptionsItemSelected(item)) {
        return true;
    }

    if (item.getItemId() == R.id.action_example) {
        Toast.makeText(getActivity(), "Example action.", Toast.LENGTH_SHORT).show();
        return true;
    }

    return super.onOptionsItemSelected(item);
}

/**
 * Per the navigation drawer design guidelines, updates the action bar to show the global app
 * 'context', rather than just what's in the current screen.
 */
private void showGlobalContextActionBar() {
    ActionBar actionBar = getActionBar();
    actionBar.setDisplayShowTitleEnabled(true);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
    actionBar.setTitle(R.string.app_name);
}

private ActionBar getActionBar() {
    return ((ActionBarActivity) getActivity()).getSupportActionBar();
}

/**
 * Callbacks interface that all activities using this fragment must implement.
 */
public static interface NavigationDrawerCallbacks {
    /**
     * Called when an item in the navigation drawer is selected.
     */
    void onNavigationDrawerItemSelected(int position);
}
}

Would it be better and easier to create an app with the Navigation Drawer from scratch, rather than using a pre-built?

从头开始使用 Navigation Drawer 创建应用程序，而不是使用预先构建的应用程序会更好更容易吗？

Help is much appreciated.

非常感谢帮助。

采纳答案by user2511882

You will need to setup a setOnItemClickListener on your drawerLayout(the id of the listview in your xml file)

您需要在 drawerLayout（xml 文件中列表视图的 id）上设置一个 setOnItemClickListener

Example:

例子：

    drawerLayout.setOnItemClickListener(new ListView.onItemClickListener){
    @Override
            public void onItemClick(AdapterView<?> parent, View view, int position,
                    long id) {

                displayView(position);
            }}

    private void displayView(int position) {

            switch (position) {
            case 0:
                fragment = new FirstFragment();
                break;
            case 1:
                fragment = new SecondFragment();
                break;
if (fragment != null) {
            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
                    .replace(R.id.frame_layout_id, fragment).commit(); //

And you need to make separate java class for the FirstFragment and SecondFragment with whatever content you need.

并且您需要使用您需要的任何内容为 FirstFragment 和 SecondFragment 制作单独的 java 类。

回答by Dat30

Well, I'll left this here in case someone needs help switching Fragments in an "Android Studio" Navigation Drawer project

好吧，如果有人需要帮助在“Android Studio”导航抽屉项目中切换片段，我会留在这里

The answer proposed by user2511882, uses the following:

user2511882 提出的答案使用以下内容：

fragment = new FirstFragment();

But the code generated by "Android Studio" uses:

但是“Android Studio”生成的代码使用：

fragment =  FirstFragment.newInstance();

(which is a better practice; see why HERE)

（这是一个更好的做法；看看为什么在这里）

That's why his answer doesn't work for your project.

这就是为什么他的答案不适用于您的项目。

In your case, you have to use something like:

在您的情况下，您必须使用以下内容：

  @Override
    public void onNavigationDrawerItemSelected(int position) {

        Fragment fragment = null;
        switch (position){
            case 0:
                fragment = FirstFragment.newInstance(position + 1);
                break;
            case 1:
                fragment = SecondFragment.newInstance(position + 1);
                break;

        }
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.container, fragment)
                .commit();
    }

In "Android Studio" it is also a good practice to read the comments and "TODOS" incorporated in the auto generated code.

在“Android Studio”中，阅读自动生成代码中的注释和“TODOS”也是一个好习惯。

best regards.

此致。

回答by Mansukh Ahir

get Item position in navigation view you can set first 0th position menu default by

在导航视图中获取项目位置，您可以通过默认设置第一个第 0 个位置菜单

navigationView.getMenu().getItem(0); // default selected menu

导航视图.getMenu().getItem(0); // 默认选中菜单

displayview(navigationView.getMenu().getItem(0));

private void setupDrawerContent(final NavigationView navigationView) {
        navigationView.setNavigationItemSelectedListener(
                new NavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(MenuItem menuItem) {
                        displayView(menuItem);
                        return true;
                    }
                });
    }


 public void displayView(MenuItem menuItem) {
        Fragment fragment = null;
        switch (menuItem.getItemId()) {
            case R.id.nav_home:
               // fragment = new CheeseListFragment();
                break;
            case R.id.nav_messages:
                fragment = new MessageFragment();
                break;
        }

        if(fragment != null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, fragment)
                    .commit();

            menuItem.setChecked(true);
            mDrawerLayout.closeDrawers();
        }
    }

回答by Mansukh Ahir

get Item position in navigation view you can set first 0th position menu default by

在导航视图中获取项目位置，您可以通过默认设置第一个第 0 个位置菜单

navigationView.getMenu().getItem(0); // default selected menu