我使用一个AlarmManager来触发一个广播信号的意图。以下是我的代码:
AlarmManager mgr = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(this, Wakeup.class);
try
{
PendingIntent pi = PendingIntent.getBroadcast(this, 0, i, 0);
Long elapsed += // sleep time;
mgr.set(AlarmManager.RTC_WAKEUP, elapsed, pi);
}
catch(Exception r)
{
Log.v(TAG, "RunTimeException: " + r);
}
我从一个活动调用这个代码，所以我不知道我如何得到以下错误…
ERROR/AndroidRuntime(7557): java.lang.RuntimeException: Unable to start receiver com.wcc.Wakeup: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
有时在没有显式调用startActivity(…)的情况下也会发生此错误。例如，有些人可能在Crashlytics中看到过这样的堆栈跟踪:
Fatal Exception: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
at android.app.ContextImpl.startActivity(ContextImpl.java:1597)
at android.app.ContextImpl.startActivity(ContextImpl.java:1584)
at android.content.ContextWrapper.startActivity(ContextWrapper.java:337)
at android.text.style.URLSpan.onClick(URLSpan.java:62)
at android.text.method.LinkMovementMethod.onTouchEvent(LinkMovementMethod.java:217)
at android.widget.TextView.onTouchEvent(TextView.java:9522)
at android.view.View.dispatchTouchEvent(View.java:8968)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.widget.AbsListView.dispatchTouchEvent(AbsListView.java:5303)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2709)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2425)
at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2559)
at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1767)
at android.app.Activity.dispatchTouchEvent(Activity.java:2866)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:67)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:67)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2520)
at android.view.View.dispatchPointerEvent(View.java:9173)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4706)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4544)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4068)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4121)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4087)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4201)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4095)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4258)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4068)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4121)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4087)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4095)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4068)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6564)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6454)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6425)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6654)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
at android.os.MessageQueue.nativePollOnce(MessageQueue.java)
at android.os.MessageQueue.next(MessageQueue.java:143)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:5942)
at java.lang.reflect.Method.invoke(Method.java)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
您可能想知道您做错了什么，因为跟踪只包括框架代码。这里有一个例子可以说明这是如何发生的。假设我们在一个片段中。
Activity activity = getActivity();
Context activityContext = activity;
Context appContext = activityContext.getApplicationContext();
LayoutInflater inflater = LayoutInflater.from(appContext); // whoops!
View view = inflater.inflate(R.layout.some_layout, parent, false);
TextView tvWithLinks = (TextView) view.findViewById(R.id.tv_with_links);
tvWithLinks.setMovementMethod(LinkMovementMethod.getInstance()); // whoops!!
现在，当用户点击那个文本视图时，你的应用程序会随着上面的堆栈跟踪而崩溃。这是因为布局扩展器具有对应用程序上下文的引用，因此文本视图具有应用程序上下文。单击该文本视图隐式地调用appContext.startActivity(…)。
最后一点:我在Android 4、5、6和7设备上进行了测试。它只影响到4 5和6。Android 7设备调用appContext.startActivity(…)显然没有问题。
我希望这能帮助到其他人!
对于同一个活动的多个实例，使用下面的代码段，
注意:这个片段，我在我的活动之外使用。确保你的AndroidManifest文件不包含android:launchMode="singleTop|singleInstance"。如果需要，你可以把它改成android:launchMode="standard"。
Intent i = new Intent().setClass(mActivity.getApplication(), TestUserProfileScreenActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
// Launch the new activity and add the additional flags to the intent
mActivity.getApplication().startActivity(i);
这对我来说很好。霍普，这为别人节省了时间。如果有人找到更好的方法，请与我们分享。
〇“Android Doc”
FLAG_ACTIVITY_NEW_TASK requirement is now enforced
With Android 9, you cannot start an activity from a non-activity
context unless you pass the intent flag FLAG_ACTIVITY_NEW_TASK. If you
attempt to start an activity without passing this flag, the activity
does not start, and the system prints a message to the log.
Note: The flag requirement has always been the intended behavior, and
was enforced on versions lower than Android 7.0 (API level 24). A bug
in Android 7.0 prevented the flag requirement from being enforced.
这意味着for (Build.VERSION)。SDK_INT <= Build.VERSION_CODES.M) || (Build.VERSION. m)SDK_INT >= Build.VERSION_CODES.P)必须添加Intent。FLAG_ACTIVITY_NEW_TASK在Activity上下文外部调用startActivity()时。
所以最好为所有版本添加标记-
...
Intent i = new Intent(this, Wakeup.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
...
