FragmentActivity上ActionBar上的空指针exception
我在运行时收到此错误。
java.lang.RuntimeException：无法恢复活动java.lang.NullPointerException：尝试在空对象引用上调用虚方法’void android.app.ActionBar.setDisplayShowHomeEnabled（boolean）’
堆栈跟踪：
01-22 06:32:55.509: E/AndroidRuntime(3728): FATAL EXCEPTION: main 01-22 06:32:55.509: E/AndroidRuntime(3728): Process: com.qrme.quranmadeeasy, PID: 3728 01-22 06:32:55.509: E/AndroidRuntime(3728): java.lang.RuntimeException: Unable to resume activity {com.qrme.quranmadeeasy/com.qrme.quranmadeeasy.InnerPageActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayShowHomeEnabled(boolean)' on a null object reference 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2951) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2982) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2365) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.ActivityThread.access$800(ActivityThread.java:144) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.os.Handler.dispatchMessage(Handler.java:102) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.os.Looper.loop(Looper.java:135) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.ActivityThread.main(ActivityThread.java:5221) 01-22 06:32:55.509: E/AndroidRuntime(3728): at java.lang.reflect.Method.invoke(Native Method) 01-22 06:32:55.509: E/AndroidRuntime(3728): at java.lang.reflect.Method.invoke(Method.java:372) 01-22 06:32:55.509: E/AndroidRuntime(3728): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 01-22 06:32:55.509: E/AndroidRuntime(3728): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 01-22 06:32:55.509: E/AndroidRuntime(3728): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayShowHomeEnabled(boolean)' on a null object reference 01-22 06:32:55.509: E/AndroidRuntime(3728): at com.qrme.quranmadeeasy.InnerPageActivity.ActionBar(InnerPageActivity.java:203) 01-22 06:32:55.509: E/AndroidRuntime(3728): at com.qrme.quranmadeeasy.InnerPageActivity.onResume(InnerPageActivity.java:71) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1241) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.Activity.performResume(Activity.java:6019) 01-22 06:32:55.509: E/AndroidRuntime(3728): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2940) 01-22 06:32:55.509: E/AndroidRuntime(3728): ... 11 more InnerPageActivity.java：
public class InnerPageActivity extends FragmentActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.copyactivity_single_page); } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); initialize(); ActionBar(); --->71 st line } public void ActionBar() { ActionBar mActionBar = getActionBar(); mActionBar.setDisplayShowHomeEnabled(false); -->203rd line mActionBar.setDisplayShowTitleEnabled(false); mActionBar.setBackgroundDrawable(new ColorDrawable(Color .parseColor("#356AA0"))); mActionBar.setCustomView(mCustomView); mActionBar.setDisplayShowCustomEnabled(true); } }
styles.xml：
manifest.xml文件：
........
我不知道如何解决这个问题。任何人都可以帮助我。谢谢。
你应该改变
public class InnerPageActivity extends FragmentActivity
至
public class InnerPageActivity extends ActionBarActivity
并且还改变mActionBar = getSupportActionBar();
由于您使用的是支持主题（AppCompat）和支持活动（FragmentActivity），而不是
getActionBar()
呼叫
getSupportActionBar()
您可以从AppCompatActivity扩展并调用getSupportActionBar（）