java.lang.NullPointerException:尝试调用虚拟方法';int android.view.ViewGroup.getPaddingLeft()和#x27;关于空对象引用
我试图使用意图来启动活动,但提到的错误发生在第二个活动的setContentView()上 这是我的代码和布局文件 itemactivity.xml:java.lang.NullPointerException:尝试调用虚拟方法';int android.view.ViewGroup.getPaddingLeft()和#x27;关于空对象引用,java,android,android-intent,layout,Java,Android,Android Intent,Layout,我试图使用意图来启动活动,但提到的错误发生在第二个活动的setContentView()上 这是我的代码和布局文件 itemactivity.xml: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_height="match_parent" android:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical">
</LinearLayout>
项目活动:
@Override
protected void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.itemactivity); // this is where error occurs
super.onCreate(savedInstanceState);
}
以下是完整的错误日志:
java.lang.RuntimeException: Unable to start activity ComponentInfo{bertaberim.team.beertaberim/bertaberim.team.beertaberim.ItemActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.ViewGroup.getPaddingLeft()' on a null object reference
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3119)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3218)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at android.app.ActivityThread.access$1000(ActivityThread.java:198)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1676)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at android.os.Looper.loop(Looper.java:145)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:6837)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:372)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
11-04 23:01:20.621 20634-20634/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
您需要先调用
super.onCreate()
对活动进行必要的初始化,然后再设置其视图。只需翻转这两条线:
super.onCreate(savedInstanceState);
setContentView(R.layout.itemactivity); // this is where error occurs
有关此方法的详细信息,请查看。您应该在所有视图就绪后使用它,您可以在super.onResume()之后调用它
super.onCreate(savedInstanceState);
setContentView(R.layout.itemactivity); // this is where error occurs