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我只是尝试在显示尺寸小的Android N中运行我的应用程序。

我的layout.xml

    <RelativeLayout
    android:id="@+id/layout_top"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_alignParentTop="true"
    android:alpha="0.77"
    android:background="#000000" >

    <ImageView
        android:id="@+id/img_back"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="10dp"
        android:src="@drawable/ic_ham_menu" />

    <TextView
        android:id="@+id/txtback"
        style="@style/textviewstyle_robotoRegular"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginLeft="5dp"
        android:layout_toRightOf="@+id/img_back"
        android:text="@string/msgs_to_rj_heading"
        android:textColor="#CCFFFFFF"
        android:textSize="20sp" />



<ImageView
    android:id="@+id/img_alarm"
    android:layout_width="wrap_content"
    android:layout_height="fill_parent"
    android:layout_alignParentRight="true"
    android:layout_marginRight="15dp"   
    android:src="@drawable/ic_timer_default"    
    android:visibility="visible" />

</RelativeLayout>

我试图将 id 称为“img_alarm”

img_alarm = (ImageView) rootView.findViewById(R.id.img_alarm);

当 Android N 显示尺寸较小时，图像未显示在 UI 中，也未设置图像 ID。当我们更改显示尺寸时显示在 UI 中并且其 id 已设置。

我不明白为什么在 Android N 中显示尺寸较小时不显示。

我收到错误

引起：java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法“int android.widget.ImageView.getId()”

java.lang.RuntimeException: Unable to resume activity {org.radiomango.app/org.radiomango.app.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.widget.ImageView.getId()' on a null object reference
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3385)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3425)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2698)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1445)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6044)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.widget.ImageView.getId()' on a null object reference
at org.radiomango.app.HomeFragment.onResume(HomeFragment.java:322)
at android.app.Fragment.performResume(Fragment.java:2398)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1032)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1171)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1153)
at android.app.FragmentManagerImpl.dispatchResume(FragmentManager.java:2049)
at android.app.FragmentController.dispatchResume(FragmentController.java:198)
at android.app.Activity.performResume(Activity.java:6783)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3362)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3425) 
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2698) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1445) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6044) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 

爪哇

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.activity_home, container, false);
  img_alarm = (ImageView) rootView.findViewById(R.id.img_alarm);
}
@Override
public void onResume() {
    super.onResume();
if (TimeSet == true) {
  img_alarm.setImageResource(R.drawable.ic_timer_default);
} else {
  img_alarm.setImageResource(R.drawable.ic_timer_active);
}
}

显示更改是否需要布局更改？

4

1 回答 1

-1

最后我得到了解决方案在 Android N 中，当显示尺寸很小时，我们需要在 res 文件夹中放置一个名为layout-sw320dp的布局。

有问题的布局复制到此布局。然后问题就解决了

于 2016-07-15T04:19:59.423 回答