java空指针异常碎片活动
我在fragmentactivity中收到一个nullpointer异常错误
以下是日志目录:
11-04 06:29:51.550: E/AndroidRuntime(19286): FATAL EXCEPTION: main
11-04 06:29:51.550: E/AndroidRuntime(19286): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dooba.beta/com.dooba.beta.MainActivity}: java.lang.NullPointerException
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.ActivityThread.access$600(ActivityThread.java:130)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.os.Handler.dispatchMessage(Handler.java:99)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.os.Looper.loop(Looper.java:137)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.ActivityThread.main(ActivityThread.java:4745)
11-04 06:29:51.550: E/AndroidRuntime(19286): at java.lang.reflect.Method.invokeNative(Native Method)
11-04 06:29:51.550: E/AndroidRuntime(19286): at java.lang.reflect.Method.invoke(Method.java:511)
11-04 06:29:51.550: E/AndroidRuntime(19286): at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
11-04 06:29:51.550: E/AndroidRuntime(19286): at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-04 06:29:51.550: E/AndroidRuntime(19286): at dalvik.system.NativeStart.main(Native Method)
11-04 06:29:51.550: E/AndroidRuntime(19286): Caused by: java.lang.NullPointerException
11-04 06:29:51.550: E/AndroidRuntime(19286): at com.dooba.beta.MainActivity.onCreate(MainActivity.java:51)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.Activity.performCreate(Activity.java:5008)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
11-04 06:29:51.550: E/AndroidRuntime(19286): at 安卓.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
11-04 06:29:51.550: E/AndroidRuntime(19286): ... 11 more
我认为错误发生在以下几行中:
mDrawerList.setAdapter(new ArrayAdapter<String>(getActionBar()
.getThemedContext(), 安卓.R.layout.simple_list_item_1,
mOptionMenu));
以下是整个活动代码:
import 安卓.app.ActionBar;
import 安卓.app.Activity;
import 安卓.content.res.Configuration;
import 安卓.os.Bundle;
import 安卓.support.v4.app.ActionBarDrawerToggle;
import 安卓.support.v4.app.ActivityCompat;
import 安卓.support.v4.app.Fragment;
import 安卓.support.v4.app.FragmentActivity;
import 安卓.support.v4.app.FragmentManager;
import 安卓.support.v4.widget.DrawerLayout;
import 安卓.view.Menu;
import 安卓.view.MenuItem;
import 安卓.support.v7.app.ActionBarActivity;
import 安卓.view.View;
import 安卓.widget.AdapterView;
import 安卓.widget.AdapterView.OnItemClickListener;
import 安卓.widget.ArrayAdapter;
import 安卓.widget.ListView;
import 安卓.widget.RelativeLayout;
import 安卓.widget.Toast;
public class MainActivity extends FragmentActivity {
private String[] mOptionMenu;
private DrawerLayout mDrawerLayout;
private RelativeLayout mDrawerRelativeLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mTitleSection;
private CharSequence mTitleApp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mOptionMenu = new String[] { "Opción 1", "Opción 2", "Opción 3" };
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerRelativeLayout = (RelativeLayout)
findViewById(R.id.left_drawer);
mDrawerList = (ListView) findViewById(R.id.list_view_drawer);
mDrawerList.setAdapter(new ArrayAdapter<String>(getActionBar()
.getThemedContext(), 安卓.R.layout.simple_list_item_1,
mOptionMenu));
mDrawerList.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Fragment fragment = null;
switch (position) {
case 0:
fragment = new FirstFragment();
break;
case 1:
fragment = new SecondFragment();
break;
case 2:
fragment = new ThirdFragment();
break;
}
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.content_frame, fragment).commit();
mDrawerList.setItemChecked(position, true);
mTitleSection = mOptionMenu[position];
getActionBar().setTitle(mTitleSection);
mDrawerLayout.closeDrawer(mDrawerRelativeLayout);
}
});
mDrawerList.setItemChecked(0, true);
mTitleSection = getTitle();
mTitleApp = getTitle();
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
R.drawable.ic_drawer, R.string.drawer_open,
R.string.drawer_close) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitleSection);
ActivityCompat.invalidateOptionsMenu(MainActivity.this);
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mTitleSection);
ActivityCompat.invalidateOptionsMenu(MainActivity.this);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main_activity_actions, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
switch (item.getItemId()) {
case R.id.action_settings:
Toast.makeText(this, "Settings", Toast.LENGTH_SHORT).show();
;
break;
default:
return super.onOptionsItemSelected(item);
}
return true;
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
mDrawerToggle.syncState();
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mDrawerToggle.onConfigurationChanged(newConfig);
}
}
如果需要任何澄清,请告诉我。 提前谢谢
# 1 楼答案
而不是
使用
this
# 2 楼答案
因为您正在导入android。支持v7。应用程序。ActionBarActivity,我想你应该使用
而不是