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我的 XML 中有一个SwipeView项，当我尝试从我的 java 类中访问它时，sometimes it returns null. 在昨天的某个时候，虽然有一个断点来调试一切都工作正常，但这只是几次。我已经尝试清理我的项目。

自定义 ListView XML 布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="horizontal">

    <com.daimajia.swipe.SwipeLayout
        android:id="@+id/swipeEvents" - this does not belong to activity_all_events
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    More Code...
    </com.daimajia.swipe.SwipeLayout>
</LinearLayout>

Java 类- 这会调用包含 CustomAdapter 的 ListView 和自定义 xml 视图的 XML 布局

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_all_events);

        SwipeLayout swipeLayout =  (SwipeLayout)findViewById(R.id.swipeEvents); - this does not belong to activity_all_events.xml
        //set show mode.
        swipeLayout.setShowMode(SwipeLayout.ShowMode.LayDown);

        More Code...
}

错误日志 

                                                                             java.lang.RuntimeException: Unable to start activity ComponentInfo{cmario.com.xxxx/cmario.com.xxxx.events.AllEvents}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.daimajia.swipe.SwipeLayout.setShowMode(com.daimajia.swipe.SwipeLayout$ShowMode)' on a null object reference
                                                                                 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
                                                                                 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                                                                                 at android.app.ActivityThread.-wrap11(ActivityThread.java)
                                                                                 at android.app.ActivityThread$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$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                                                                              Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.daimajia.swipe.SwipeLayout.setShowMode(com.daimajia.swipe.SwipeLayout$ShowMode)' on a null object reference
                                                                                 at cmario.com.xxxx.events.AllEvents.onCreate(AllEvents.java:94)
                                                                                 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)

 

  1. 与我的构造函数有什么关系？
  2. 我试图访问 XML 属性的点（在 CustomAdapter 初始化之前）？在被调用后尝试过，CustomAdapter但输出仍然相同

提前感谢任何愿意帮助我提出建议的人

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0 回答 0