我正在Android Studio中实现菜单抽屉。
我使用了包含抽屉设置的DrawerFragment
。我还使用了包含在抽屉中显示列表视图的DrawerAdapter
。
这是我的MainActivity.java文件。
public class MainActivity extends AppCompatActivity{
private DrawerFragment drawerFragment;
private Toolbar toolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
drawerFragment = (DrawerFragment) getFragmentManager().findFragmentById(R.id.navigation_drawer);
drawerFragment.setUp(R.id.navigation_drawer,toolbar,(DrawerLayout) findViewById(R.id.drawer_layout),MainActivity.this);
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.mithilamin.menudrawer.MainActivity">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="100dp"
android:id="@+id/toolbar"
android:layout_gravity="center_horizontal"
android:background="@drawable/vehicle_toolbar"
android:layout_alignParentTop="true">
</android.support.v7.widget.Toolbar>
<TextView
android:id="@+id/vehicle_toolbar_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="hello_world"
android:layout_gravity="right|center_vertical"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@android:color/background_dark"
android:textSize="24sp"
android:alpha="0.7"
android:paddingLeft="20dp"
android:paddingRight="30dp"
android:paddingTop="10dp"
android:paddingBottom="10dp" />
</FrameLayout>
<fragment android:id="@+id/navigation_drawer"
android:layout_width="@dimen/drawer_width" android:layout_height="match_parent"
android:layout_gravity="start"
class = "com.example.mithilamin.menudrawer.drawer.DrawerFragment" />
错误
(注:此处为错误提示)
E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.mithilamin.menudrawer, PID: 16507
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mithilamin.menudrawer/com.example.mithilamin.menudrawer.MainActivity}: android.view.InflateException: Binary XML file line #40: Binary XML file line #40: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: android.view.InflateException: Binary XML file line #40: Binary XML file line #40: Error inflating class fragment
at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
at com.example.mithilamin.menudrawer.MainActivity.onCreate(MainActivity.java:21)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: android.view.InflateException: Binary XML file line #40: Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:782)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
at com.example.mithilamin.menudrawer.MainActivity.onCreate(MainActivity.java:21)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.os.Bundle.getInt(java.lang.String)' on a null object reference
at com.example.mithilamin.menudrawer.drawer.DrawerFragment.onCreate(DrawerFragment.java:46)
at android.app.Fragment.performCreate(Fragment.java:2198)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:942)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
at android.app.FragmentManagerImpl.addFragment(FragmentManager.java:1228)
at android.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2201)
at android.app.FragmentController.onCreateView(FragmentController.java:98)
at android.app.Activity.onCreateView(Activity.java:5546)
at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:34)
at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:754)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
at com.example.mithilamin.menudrawer.MainActivity.onCreate(MainActivity.java:21)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
DrawerFragment.java
public class DrawerFragment extends Fragment {
private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";
private Activity drawerCallingActivity;
private ListView mainList, settingsList;
private View fragmentContainerView;
private int currentSelectPosition = 0;
private ActionBarDrawerToggle drawerToggle;
protected List<DrawerData> drawerDataList = new ArrayList<>();
protected List<DrawerData> drawerSettingList = new ArrayList<>();
private DrawerLayout drawerLayout;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(savedInstanceState==null)
currentSelectPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
drawerDataList.add(new DrawerData(getString(R.string.drawer_item_1),R.drawable.vehicle_drawer_icon,0));
drawerDataList.add(new DrawerData(getString(R.string.drawer_item_2), R.drawable.expense_drawer_icon, 0));
drawerSettingList.add(new DrawerData(getString(R.string.drawer_settings_item_2), R.drawable.logout_drawer_icon, 0));
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.drawerbar,container,false);
mainList = (ListView) view.findViewById(R.id.drawer_list);
settingsList = (ListView) view.findViewById(R.id.drawer_settings);
mainList.setAdapter(new DrawerAdapter(drawerDataList, getActivity()));
settingsList.setAdapter(new DrawerAdapter(drawerSettingList, getActivity()));
mainList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
});
settingsList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectSettingItem(position);
}
});
TextView userName = (TextView) view.findViewById(R.id.drawer_text_username);
mainList.setItemChecked(currentSelectPosition, true);
return view;
}
public void setUp(int fragmentId, Toolbar toolbar, DrawerLayout drawerLayout, Activity activity) {
fragmentContainerView = getActivity().findViewById(fragmentId);
this.drawerLayout = drawerLayout;
this.drawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
this.drawerCallingActivity = activity;
drawerToggle = new ActionBarDrawerToggle(getActivity(),this.drawerLayout,toolbar,R.string.open_drawer,R.string.close_drawer){
@Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
if(!isAdded())
return;
getActivity().invalidateOptionsMenu();
}
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
if(!isAdded())
return;;
getActivity().invalidateOptionsMenu();
}
};
drawerLayout.post(new Runnable() {
@Override
public void run() {
drawerToggle.syncState();
}
});
drawerLayout.setDrawerListener(drawerToggle);
}
private void selectItem(int position) {
currentSelectPosition = position;
if (mainList != null) {
mainList.setItemChecked(position, true);
}
if (drawerLayout != null) {
drawerLayout.closeDrawer(fragmentContainerView);
}
switch (position){
case 0:
Toast.makeText(getActivity(),getString(R.string.drawer_item_1),Toast.LENGTH_SHORT).show();
break;
case 1:
Toast.makeText(getActivity(),getString(R.string.drawer_item_2),Toast.LENGTH_SHORT).show();
}
}
private void selectSettingItem(int position) {
if (settingsList != null)
settingsList.setItemChecked(position, true);
if (drawerLayout != null)
drawerLayout.closeDrawer(fragmentContainerView);
switch (position) {
case 0:
Toast.makeText(getActivity(), getString(R.string.drawer_settings_item_2), Toast.LENGTH_SHORT).show();
break;
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(STATE_SELECTED_POSITION, currentSelectPosition);
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
drawerToggle.onConfigurationChanged(newConfig);
}
}
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.os.Bundle.getInt(java.lang.String)' on a null object reference at com.example.mithilamin.menudrawer.drawer.DrawerFragment.onCreate(DrawerFragment.java:46)
。 - Eric B.