无法解析 main activity java class 中的符号

Question

我找不到这里的问题！我正在按照 this 教程构建带片段的导航抽屉，但我找不到修复 "cannot resolve symbol error" 的方法。错误在 "drawer_nav_item"。我一直在寻找未使用的类，其他时候它已被使用但找不到！请帮忙！我可以根据要求提供更多代码

这是我的activity_main.xml

package com.nhscoding.safe2tell;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.ListView;
import com.nhscoding.safe2tell.AboutClass;
import com.nhscoding.safe2tell.FragmentNavigationDrawer;
import com.nhscoding.safe2tell.LearnClass;
import com.nhscoding.safe2tell.R;
import com.nhscoding.safe2tell.SettingsClass;
import com.nhscoding.safe2tell.StoriesClass;
import com.nhscoding.safe2tell.SubmitClass;

public class MainActivity extends FragmentActivity {
    private FragmentNavigationDrawer dlDrawer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Find our drawer view
        dlDrawer = (FragmentNavigationDrawer) findViewById(R.id.drawer_layout);
        // Setup drawer view
        dlDrawer.setupDrawerConfiguration((ListView) findViewById(R.id.lvDrawer),
                R.layout.drawer_nav_item, R.id.flContent);
        // Add nav items
        dlDrawer.addNavItem("Submit", "Submit Class", SubmitClass.class);
        dlDrawer.addNavItem("Second", "Second Fragment", StoriesClass.class);
        dlDrawer.addNavItem("Third", "Third Fragment", LearnClass.class);
        dlDrawer.addNavItem("Fouth", "Fourth Fragment", AboutClass.class);
        dlDrawer.addNavItem("Fifth", "Fifth Fragment", SettingsClass.class);
        // Select default
        if (savedInstanceState == null) {
            dlDrawer.selectDrawerItem(0);
        }
    }


    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content
        if (dlDrawer.isDrawerOpen()) {
            // Uncomment to hide menu items
            // menu.findItem(R.id.mi_test).setVisible(false);
        }
        return super.onPrepareOptionsMenu(menu);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        // Uncomment to inflate menu items to Action Bar
        // inflater.inflate(R.menu.main, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // The action bar home/up action should open or close the drawer.
        // ActionBarDrawerToggle will take care of this.
        if (dlDrawer.getDrawerToggle().onOptionsItemSelected(item)) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        dlDrawer.getDrawerToggle().syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Pass any configuration change to the drawer toggles
        dlDrawer.getDrawerToggle().onConfigurationChanged(newConfig);
    }

}

这是我的导航抽屉Class

package com.nhscoding.safe2tell;

import java.util.ArrayList;

import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import com.nhscoding.safe2tell.R;

public class FragmentNavigationDrawer extends DrawerLayout {
    private ActionBarDrawerToggle drawerToggle;
    private ListView lvDrawer;
    private ArrayAdapter<String> drawerAdapter;
    private ArrayList<FragmentNavItem> drawerNavItems;
    private int drawerContainerRes;

    public FragmentNavigationDrawer(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public FragmentNavigationDrawer(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public FragmentNavigationDrawer(Context context) {
        super(context);
    }

    // setupDrawerConfiguration((ListView) findViewById(R.id.lvDrawer), R.layout.drawer_list_item, R.id.flContent);
    public void setupDrawerConfiguration(ListView drawerListView, int drawerItemRes, int drawerContainerRes) {
        // Setup navigation items array
        drawerNavItems = new ArrayList<FragmentNavigationDrawer.FragmentNavItem>();
        // Set the adapter for the list view
        drawerAdapter = new ArrayAdapter<String>(getActivity(), drawerItemRes,
                new ArrayList<String>());
        this.drawerContainerRes = drawerContainerRes;
        // Setup drawer list view and related adapter
        lvDrawer = drawerListView;
        lvDrawer.setAdapter(drawerAdapter);
        // Setup item listener
        lvDrawer.setOnItemClickListener(new FragmentDrawerItemListener());
        // ActionBarDrawerToggle ties together the the proper interactions
        // between the sliding drawer and the action bar app icon
        drawerToggle = setupDrawerToggle();
        setDrawerListener(drawerToggle);
        // set a custom shadow that overlays the main content when the drawer
        setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
        // Setup action buttons
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);
    }

    // addNavItem("First", "First Fragment", FirstFragment.class)
    public void addNavItem(String navTitle, String windowTitle, Class<? extends Fragment> fragmentClass) {
        drawerAdapter.add(navTitle);
        drawerNavItems.add(new FragmentNavItem(windowTitle, fragmentClass));
    }

    /** Swaps fragments in the main content view */
    public void selectDrawerItem(int position) {
        // Create a new fragment and specify the planet to show based on
        // position
        FragmentNavItem navItem = drawerNavItems.get(position);
        Fragment fragment = null;
        try {
            fragment = navItem.getFragmentClass().newInstance();
            Bundle args = navItem.getFragmentArgs();
            if (args != null) {
                fragment.setArguments(args);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        // Insert the fragment by replacing any existing fragment
        FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(drawerContainerRes, fragment).commit();

        // Highlight the selected item, update the title, and close the drawer
        lvDrawer.setItemChecked(position, true);
        setTitle(navItem.getTitle());
        closeDrawer(lvDrawer);
    }


    public ActionBarDrawerToggle getDrawerToggle() {
        return drawerToggle;
    }


    private FragmentActivity getActivity() {
        return (FragmentActivity) getContext();
    }

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

    private void setTitle(CharSequence title) {
        getSupportActionBar().setTitle(title);
    }

    private class FragmentDrawerItemListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectDrawerItem(position);
        }
    }

    private class FragmentNavItem {
        private Class<? extends Fragment> fragmentClass;
        private String title;
        private Bundle fragmentArgs;

        public FragmentNavItem(String title, Class<? extends Fragment> fragmentClass) {
            this(title, fragmentClass, null);
        }

        public FragmentNavItem(String title, Class<? extends Fragment> fragmentClass, Bundle args) {
            this.fragmentClass = fragmentClass;
            this.fragmentArgs = args;
            this.title = title;
        }

        public Class<? extends Fragment> getFragmentClass() {
            return fragmentClass;
        }

        public String getTitle() {
            return title;
        }

        public Bundle getFragmentArgs() {
            return fragmentArgs;
        }
    }

    private ActionBarDrawerToggle setupDrawerToggle() {
        return new ActionBarDrawerToggle(getActivity(), /* host Activity */
                this, /* DrawerLayout object */
                R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
                R.string.drawer_open, /* "open drawer" description for accessibility */
                R.string.drawer_close /* "close drawer" description for accessibility */
        ) {
            public void onDrawerClosed(View view) {
                // setTitle(getCurrentTitle());
                // call onPrepareOptionsMenu()
                getActivity().supportInvalidateOptionsMenu();
            }

            public void onDrawerOpened(View drawerView) {
                // setTitle("Navigate");
                // call onPrepareOptionsMenu()
                getActivity().supportInvalidateOptionsMenu();
            }
        };
    }

    public boolean isDrawerOpen() {
        return isDrawerOpen(lvDrawer);
    }


}

Answer 1

问题是您没有定义布局：drawer_nav_item

@Override
public void onCreate(Bundle sIS){ 
    super(sIS);
    setContentView(R.layout.activity_main);
    // Find our drawer view
    dlDrawer = (FragmentNavigationDrawer) findViewById(R.id.drawer_layout);
    // Setup drawer view
    dlDrawer.setupDrawerConfiguration((ListView)findViewById(R.id.lvDrawer),
        R.layout.drawer_nav_item, /* <- this layout has not been defined 
                                     in your layouts folder */
        R.id.flContent);
    ...
}

无法解析 main activity java class 中的符号

Cannot resolve symbol in main activity java class

android

android-fragments

android-studio

navigation-drawer