Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK fla
阿新 • • 發佈：2018-12-27
今天在專案中碰到的一個錯誤：
專案中涉及到很多Activity之間相互跳轉的程式碼，如下所示的程式碼，感覺很繁瑣，因此想到了封裝一下：
Intent intent = new Intent(SplashActivity.this , MainFragmentActivity.class);
startActivity(intent);
封裝在了另一個類：UIHelper.java中
Intent intent = new Intent();
intent.setClass(context, cls);
context.startActivity(intent);
執行後，就報錯了，錯誤log:
04-09 15:55:08.165: E/AndroidRuntime(3403): android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want? 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.app.ContextImpl.startActivity(ContextImpl.java:964) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.app.ContextImpl.startActivity(ContextImpl.java:951) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.content.ContextWrapper.startActivity(ContextWrapper.java:290) 04-09 15:55:08.165: E/AndroidRuntime(3403): at com.nfschina.sign.cover.UIHelper.startUserActivity(UIHelper.java:76) 04-09 15:55:08.165: E/AndroidRuntime(3403): at com.nfschina.sign.cover.activity.SettingActivity.onPreferenceClick(SettingActivity.java:125) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.preference.Preference.performClick(Preference.java:952) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.preference.PreferenceScreen.onItemClick(PreferenceScreen.java:215) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.widget.AdapterView.performItemClick(AdapterView.java:315) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.widget.AbsListView.performItemClick(AbsListView.java:1107) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2795) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.widget.AbsListView$1.run(AbsListView.java:3470) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.os.Handler.handleCallback(Handler.java:730) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.os.Handler.dispatchMessage(Handler.java:92) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.os.Looper.loop(Looper.java:137) 04-09 15:55:08.165: E/AndroidRuntime(3403): at android.app.ActivityThread.main(ActivityThread.java:5136) 04-09 15:55:08.165: E/AndroidRuntime(3403): at java.lang.reflect.Method.invokeNative(Native Method) 04-09 15:55:08.165: E/AndroidRuntime(3403): at java.lang.reflect.Method.invoke(Method.java:525) 04-09 15:55:08.165: E/AndroidRuntime(3403): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 04-09 15:55:08.165: E/AndroidRuntime(3403): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 04-09 15:55:08.165: E/AndroidRuntime(3403): at dalvik.system.NativeStart.main(Native Method)
第一行提示：
Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
錯誤分析：
Context中有一個startActivity方法，Activity繼承自Context，過載了startActivity方法。如果使用Activity的startActivity方法，不會有任何限制，而如果使用Context的startActivity方法的話，就需要開啟一個新的的task，遇到這個異常，是因為使用了Context的startActivity方法。解決辦法是，加一個flag。
程式碼：
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK );
這樣就可以在新的task裡面啟動這個Activity了。
/**
* 啟動新的Activity
* @param context 當前Activity
* @param cls 要啟動的Activity的類
*/
public static void startUserActivity(Context context , Class cls){
Intent intent = new Intent();
intent.setClass(context, cls);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK );
context.startActivity(intent);
}