Question

我正在尝试学习并在我的Android应用程序（地址簿）中添加一些基本的Facebook功能。我最终要做的是导入朋友个人资料图片。我目前只从“FriendPickerSample”示例项目中复制/粘贴我需要的内容，该项目只是一个显示朋友选择器片段的按钮，如果我没记错的话，它会将您选择的名称放入列表中。当点击一个imageview时，我已经改变了它，它只是Toast所选择的单个名称。当我尝试调出朋友选择器时，我得到一个空指针异常，我不明白为什么。这是日志：

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.JDE.RAB/com.JDE.RAB.PickFriendsActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
at android.app.ActivityThread.access$2300(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.facebook.widget.PickerFragment.onCreateView(PickerFragment.java:152)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:871)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1083)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:635)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1431)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:523)
at com.JDE.RAB.PickFriendsActivity.onStart(PickFriendsActivity.java:112)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1129)
at android.app.Activity.performStart(Activity.java:3781)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2636)
... 11 more

这是我的onclick中的代码，它应该打开PickFriendsActivity：

if (Session.getActiveSession() == null || Session.getActiveSession().isClosed())
        {
        Session.openActiveSession(AddNewTabLayoutActivity.this, true, null);
        }//endif                
FriendPickerApplication application = (FriendPickerApplication) GetMyApplication();
application.setSelectedUsers(null);

Intent intent = new Intent(AddNewTabLayoutActivity.this, PickFriendsActivity.class);
// Note: The following line is optional, as multi-select behavior is the default for
// FriendPickerFragment. It is here to demonstrate how parameters could be passed to the
// friend picker if single-select functionality was desired, or if a different user ID was
// desired (for instance, to see friends of a friend).

//multi-select is OFF
PickFriendsActivity.populateParameters(intent, null, false, true);
Debugger.SendNotification(getApplicationContext(), "Alert", "Alert", "Starting Activity For Result", 3009);
startActivityForResult(intent, 2);

PickFriendsActivity，第112行是super.onStart（）;我应该发布整个活动源代码吗？

感谢您的帮助！

Answer 1

您也应该将res/layout/pick_friends_activity.xml复制到您自己的项目中。

试图添加Facebook朋友选择器，但获取空指针异常

1 个答案: