android - 从空白 Activity 启动抽屉导航 Activity 时应用程序崩溃

Question

This is my sarting activity...    

    public class first extends ActionBarActivity {

    public String superusername=null;

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

        Button okbtn = (Button) findViewById(R.id.okbtn);
        final EditText username = (EditText) findViewById(R.id.username);

        okbtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                superusername = username.getText().toString();
                Intent intent = new Intent(first.this, MainActivity.class);
                startActivity(intent);

            }
        });

    }

当我单击确定按钮时，应用程序崩溃。为什么？？？

如何成功启动 NavigationDrawer Activity ？？？

这是我的 list 文件...

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.susk.swayam.ABC" >

    <application
        android:allowBackup="true"
        android:icon="@drawable/icon"
        android:label="@string/app_name"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar" >
        <activity
            android:name=".first"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.FIRST" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>

</manifest>

这是 log.error....

05-21 15:46:15.098    1009-1009/com.susk.swayam.timecaller E/Trace﹕ error opening trace file: No such file or directory (2)
05-21 15:46:20.087    1009-1009/com.susk.swayam.timecaller E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.susk.swayam.timecaller/com.susk.swayam.timecaller.MainActivity}: android.view.InflateException: Binary XML file line #19: Error inflating class fragment
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: android.view.InflateException: Binary XML file line #19: Error inflating class fragment
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
            at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:249)
            at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:106)
            at com.susk.swayam.timecaller.MainActivity.onCreate(MainActivity.java:38)
            at android.app.Activity.performCreate(Activity.java:5008)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.susk.swayam.timecaller.NavigationDrawerFragment.onCreateView(NavigationDrawerFragment.java:100)
            at android.support.v4.app.Fragment.performCreateView(Fragment.java:1789)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:924)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1116)
            at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1218)
            at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2170)
            at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:300)
            at android.support.v7.app.AppCompatDelegateImplV7.callActivityOnCreateView(AppCompatDelegateImplV7.java:816)
            at android.support.v7.app.AppCompatDelegateImplV11.callActivityOnCreateView(AppCompatDelegateImplV11.java:72)
            at android.support.v7.app.AppCompatDelegateImplV7.onCreateView(AppCompatDelegateImplV7.java:804)
            at android.support.v4.view.LayoutInflaterCompatHC$FactoryWrapperHC.onCreateView(LayoutInflaterCompatHC.java:44)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:675)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
            at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:249)
            at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:106)
            at com.susk.swayam.timecaller.MainActivity.onCreate(MainActivity.java:38)
            at android.app.Activity.performCreate(Activity.java:5008)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at `enter code here`com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)

当我单击确定按钮时，应用程序崩溃。

第一个 Activity 调用 MainActivity，它是 NavigationDrawerFragment。

Answer 1

1)你必须把LogCat或者它不可能找到问题并帮助你

2) NavDrawer 不能是 Fragment。这是一个 Activity ，您将在其中调用您的 fragment 。

这是一个很好的例子:http://www.android4devs.com/2014/12/how-to-make-material-design-navigation-drawer.html

如您所见，您需要创建一个扩展 ActionBarActivity 的 Activity

public class MainActivity extends ActionBarActivity {

    //First We Declare Titles And Icons For Our Navigation Drawer List View
    //This Icons And Titles Are holded in an Array as you can see

    String TITLES[] = {"Home","Events","Mail","Shop","Travel"};
    int ICONS[] = {R.drawable.ic_home,R.drawable.ic_events,R.drawable.ic_mail,R.drawable.ic_shop,R.drawable.ic_travel};

    //Similarly we Create a String Resource for the name and email in the header view
    //And we also create a int resource for profile picture in the header view

    String NAME = "Akash Bangad";
    String EMAIL = "akash.bangad@android4devs.com";
    int PROFILE = R.drawable.aka;

    private Toolbar toolbar;                              // Declaring the Toolbar Object

    RecyclerView mRecyclerView;                           // Declaring RecyclerView
    RecyclerView.Adapter mAdapter;                        // Declaring Adapter For Recycler View
    RecyclerView.LayoutManager mLayoutManager;            // Declaring Layout Manager as a linear layout manager
    DrawerLayout Drawer;                                  // Declaring DrawerLayout

    ActionBarDrawerToggle mDrawerToggle;                  // Declaring Action Bar Drawer Toggle




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

    /* Assinging the toolbar object ot the view
    and setting the the Action bar to our toolbar
     */
    toolbar = (Toolbar) findViewById(R.id.tool_bar);
    setSupportActionBar(toolbar);




        mRecyclerView = (RecyclerView) findViewById(R.id.RecyclerView); // Assigning the RecyclerView Object to the xml View

        mRecyclerView.setHasFixedSize(true);                            // Letting the system know that the list objects are of fixed size

        mAdapter = new MyAdapter(TITLES,ICONS,NAME,EMAIL,PROFILE);       // Creating the Adapter of MyAdapter class(which we are going to see in a bit)
                                                                         // And passing the titles,icons,header view name, header view email,
                                                                         // and header view profile picture

        mRecyclerView.setAdapter(mAdapter);                              // Setting the adapter to RecyclerView

        mLayoutManager = new LinearLayoutManager(this);                 // Creating a layout Manager

        mRecyclerView.setLayoutManager(mLayoutManager);                 // Setting the layout Manager


        Drawer = (DrawerLayout) findViewById(R.id.DrawerLayout);        // Drawer object Assigned to the view
        mDrawerToggle = new ActionBarDrawerToggle(this,Drawer,toolbar,R.string.openDrawer,R.string.closeDrawer){

            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                // code here will execute once the drawer is opened( As I dont want anything happened whe drawer is
                // open I am not going to put anything here)
            }

            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                // Code here will execute once drawer is closed
            }



    }; // Drawer Toggle Object Made
        Drawer.setDrawerListener(mDrawerToggle); // Drawer Listener set to the Drawer toggle
        mDrawerToggle.syncState();               // Finally we set the drawer toggle sync State

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.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);
    }
}

然后创建适配器:

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

    private static final int TYPE_HEADER = 0;  // Declaring Variable to Understand which View is being worked on
                                               // IF the view under inflation and population is header or Item
    private static final int TYPE_ITEM = 1;

    private String mNavTitles[]; // String Array to store the passed titles Value from MainActivity.java
    private int mIcons[];       // Int Array to store the passed icons resource value from MainActivity.java

    private String name;        //String Resource for header View Name
    private int profile;        //int Resource for header view profile picture
    private String email;       //String Resource for header view email 


    // Creating a ViewHolder which extends the RecyclerView View Holder
    // ViewHolder are used to to store the inflated views in order to recycle them

    public static class ViewHolder extends RecyclerView.ViewHolder {
        int Holderid;      

        TextView textView; 
        ImageView imageView;
        ImageView profile;
        TextView Name;
        TextView email;


        public ViewHolder(View itemView,int ViewType) {                 // Creating ViewHolder Constructor with View and viewType As a parameter
            super(itemView);


            // Here we set the appropriate view in accordance with the the view type as passed when the holder object is created

            if(ViewType == TYPE_ITEM) {
                textView = (TextView) itemView.findViewById(R.id.rowText); // Creating TextView object with the id of textView from item_row.xml
                imageView = (ImageView) itemView.findViewById(R.id.rowIcon);// Creating ImageView object with the id of ImageView from item_row.xml
                Holderid = 1;                                               // setting holder id as 1 as the object being populated are of type item row
            }
            else{


                Name = (TextView) itemView.findViewById(R.id.name);         // Creating Text View object from header.xml for name
                email = (TextView) itemView.findViewById(R.id.email);       // Creating Text View object from header.xml for email
                profile = (ImageView) itemView.findViewById(R.id.circleView);// Creating Image view object from header.xml for profile pic
                Holderid = 0;                                                // Setting holder id = 0 as the object being populated are of type header view
            }
        }


    }



    MyAdapter(String Titles[],int Icons[],String Name,String Email, int Profile){ // MyAdapter Constructor with titles and icons parameter
                                            // titles, icons, name, email, profile pic are passed from the main activity as we
        mNavTitles = Titles;                //have seen earlier
        mIcons = Icons;
        name = Name;
        email = Email;
        profile = Profile;                     //here we assign those passed values to the values we declared here
        //in adapter



    }



    //Below first we ovverride the method onCreateViewHolder which is called when the ViewHolder is
    //Created, In this method we inflate the item_row.xml layout if the viewType is Type_ITEM or else we inflate header.xml
    // if the viewType is TYPE_HEADER
    // and pass it to the view holder

    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        if (viewType == TYPE_ITEM) {
            View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_row,parent,false); //Inflating the layout

            ViewHolder vhItem = new ViewHolder(v,viewType); //Creating ViewHolder and passing the object of type view

            return vhItem; // Returning the created object

            //inflate your layout and pass it to view holder

        } else if (viewType == TYPE_HEADER) {

            View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.header,parent,false); //Inflating the layout

            ViewHolder vhHeader = new ViewHolder(v,viewType); //Creating ViewHolder and passing the object of type view

            return vhHeader; //returning the object created


        }
        return null;

    }

    //Next we override a method which is called when the item in a row is needed to be displayed, here the int position
    // Tells us item at which position is being constructed to be displayed and the holder id of the holder object tell us
    // which view type is being created 1 for item row
    @Override
    public void onBindViewHolder(MyAdapter.ViewHolder holder, int position) {
        if(holder.Holderid ==1) {                              // as the list view is going to be called after the header view so we decrement the
                                                              // position by 1 and pass it to the holder while setting the text and image
            holder.textView.setText(mNavTitles[position - 1]); // Setting the Text with the array of our Titles
            holder.imageView.setImageResource(mIcons[position -1]);// Settimg the image with array of our icons
        }
        else{

            holder.profile.setImageResource(profile);           // Similarly we set the resources for header view
            holder.Name.setText(name);
            holder.email.setText(email);
        }
    }

    // This method returns the number of items present in the list
    @Override
    public int getItemCount() {
        return mNavTitles.length+1; // the number of items in the list will be +1 the titles including the header view.
    }


    // Witht the following method we check what type of view is being passed
    @Override
    public int getItemViewType(int position) { 
        if (isPositionHeader(position))
            return TYPE_HEADER;

        return TYPE_ITEM;
    }

    private boolean isPositionHeader(int position) {
        return position == 0;
    }

}

这种示例非常完美，因为它使用了新的 Material 设计组件，包括 Toolbar希望能帮助到你