我正在尝试将quickblox聊天集成到运行良好且已经在Play商店中的现有应用中。
我正在尝试使用示例聊天代码https://github.com/QuickBlox/quickblox-android-sdk/tree/master/sample-chat来实现这一点。
原始应用API的targetSdkVersion为27，由于出现错误，我不得不将其更改为28，并且必须将其迁移到androidX。
因此，在下面的代码块中，loadUsersFromQb（）从服务器向用户加载标签“ SampleTag”。如果存在聊天对话框，则会使用已加载的用户来更新该对话框，否则假定将显示用户的ListView，然后可以选择要添加到聊天组的用户。
代码
private void loadUsersFromQb() {
List<String> tags = new ArrayList<>();
try {
tags.add("SampleTag");
}catch (Exception e)
{
// Toaster.shortToast(e.getMessage());
}
progressBar.setVisibility(View.VISIBLE);
QBUsers.getUsersByTags(tags, null).performAsync(new QBEntityCallback<ArrayList<QBUser>>() {
@Override
public void onSuccess(ArrayList<QBUser> usersByTags, Bundle params) {
users = usersByTags;
Toast.makeText(SelectUsersActivity.this, users.toString(), Toast.LENGTH_SHORT).show();
if (qbChatDialog != null) {
// update occupants list form server
getDialog();
} else {
updateUsersAdapter();
}
}
@Override
public void onError(QBResponseException e) {
Toast.makeText(SelectUsersActivity.this, e.getMessage(), Toast.LENGTH_SHORT).show();
showErrorSnackbar(R.string.select_users_get_users_error, e,
new View.OnClickListener() {
@Override
public void onClick(View v) {
loadUsersFromQb();
}
});
progressBar.setVisibility(View.GONE);
}
});
}
但是
updateUsersAdapter()
结果
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources com.gill.XXX.CoreApp.getResources()' on a null object reference
updateUsersAdapter（）块如下所示
private void updateUsersAdapter() {
usersAdapter = new CheckboxUsersAdapter(this, users);
if (qbChatDialog != null) {
usersAdapter.addSelectedUsers(qbChatDialog.getOccupants());
}
usersListView.setAdapter(usersAdapter);
progressBar.setVisibility(View.GONE);
}
usersListView是从这样的类字段实例化的
private ListView usersListView;
其中ListView是一个Android API 28小部件。
该异常的完整Logcat是
2019-04-04 09:52:07.728 1200-1200/com.gill.XXX:error_activity E/CustomActivityOnCrash: The previous app process crashed. This is the stack trace of the crash:
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources com.gill.XXX.CoreApp.getResources()' on a null object reference
at com.gill.XXX.utils.UiUtils.getCircleColor(UiUtils.java:67)
at com.gill.XXX.utils.UiUtils.getColorCircleDrawable(UiUtils.java:40)
at com.gill.XXX.adapter.UsersAdapter.getView(UsersAdapter.java:74)
at com.gill.XXX.adapter.CheckboxUsersAdapter.getView(CheckboxUsersAdapter.java:41)
at android.widget.HeaderViewListAdapter.getView(HeaderViewListAdapter.java:220)
at android.widget.AbsListView.obtainView(AbsListView.java:2365)
at android.widget.ListView.makeAndAddView(ListView.java:2052)
at android.widget.ListView.fillDown(ListView.java:786)
at android.widget.ListView.fillFromTop(ListView.java:847)
at android.widget.ListView.layoutChildren(ListView.java:1826)
at android.widget.AbsListView.onLayout(AbsListView.java:2164)
at android.view.View.layout(View.java:20321)
at android.view.ViewGroup.layout(ViewGroup.java:6153)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1083)
at android.view.View.layout(View.java:20321)
at android.view.ViewGroup.layout(ViewGroup.java:6153)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:20321)
at android.view.ViewGroup.layout(ViewGroup.java:6153)
at androidx.appcompat.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:444)
at android.view.View.layout(View.java:20321)
at android.view.ViewGroup.layout(ViewGroup.java:6153)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:20321)
at android.view.ViewGroup.layout(ViewGroup.java:6153)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1791)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1635)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1544)
at android.view.View.layout(View.java:20321)
at android.view.ViewGroup.layout(ViewGroup.java:6153)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at com.android.internal.policy.DecorView.onLayout(DecorView.java:763)
at android.view.View.layout(View.java:20321)
at android.view.ViewGroup.layout(ViewGroup.java:6153)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2609)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2314)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1450)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7023)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:924)
at android.view.Choreographer.doCallbacks(Choreographer.java:732)
at android.view.Choreographer.doFrame(Choreographer.java:664)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:910)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6523)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:857)
此方法调用导致应用程序崩溃。我在stackoverflow上做了很多类似问题的搜索，但仍然无法解决问题。
在https://issuetracker.google.com/issues/120750246处同样有一个建议，可能是因为我正在API级别小于28的设备上测试该应用程序。ClassNotFoundException也出现在Logcat中。
我已经处理了好几天，任何帮助将不胜感激。