startActivity时报错Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW

startActivity时报错Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag

Free-Thinker 2021-08-15 原文

原代码如下：

Intent intent = new Intent();
intent.setClass(mContext, PhotoView.class);
Bundle bundle = new Bundle();
intent.putExtras(bundle); 
mContext.startActivity(intent);

报错如下：

06-28 11:24:40.359: E/AndroidRuntime(7397): android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity  context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.app.ContextImpl.startActivity(ContextImpl.java:617)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.content.ContextWrapper.startActivity(ContextWrapper.java:258)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at com.hotalk.ui.homepage.favorites.FavoritesListAdapter$7.onClick(FavoritesListAdapter.java:1509)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.view.View.performClick(View.java:2408)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.view.View$PerformClick.run(View.java:8816)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.os.Handler.handleCallback(Handler.java:587)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.os.Handler.dispatchMessage(Handler.java:92)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.os.Looper.loop(Looper.java:123)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at android.app.ActivityThread.main(ActivityThread.java:4627)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at java.lang.reflect.Method.invokeNative(Native Method)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at java.lang.reflect.Method.invoke(Method.java:521)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
06-28 11:24:40.359: E/AndroidRuntime(7397):     at dalvik.system.NativeStart.main(Native Method)

原因是：

　　Context中有一个startActivity方法，Activity继承自Context，重载了startActivity方法。如果使用 Activity的startActivity方法，不会有任何限制，而如果使用Context的startActivity方法的话，就需要开启一个新的task，遇到上面那个异常的，都是因为使用了Context的startActivity方法。解决办法是，加一个flag。intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

修改后代码如下：

Intent intent = new Intent();
intent.setClass(mContext, PhotoView.class);
Bundle bundle = new Bundle();
intent.putExtras(bundle);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
mContext.startActivity(intent);