FAQ_16_androidserviceintentactivity

在 Service 中启动 Activity&＃xff0c;有很多方式&＃xff0c;比如隐式启动、显式启动等。

隐式启动 Activity&＃xff0c;需要在manifest.xml 中为该 Activity 配置&＃xff0c;如下所示&＃xff1a;

MyActivity 是要在 Service 中启动的那个 Activity&＃xff0c;为其配置 action、category等。&＃xff08;category 不是必须的&＃xff09;。

在 Service 中这样启动 MyActivity&＃xff1a;

// 等效于 // Intent i &＃61; new Intent(); // i.setAction("mark.zhang"); Intent i &＃61; new Intent("mark.zhang"); // 这个不是必需的 i.addCategory(Intent.CATEGORY_DEFAULT); startActivity(i);

也可以显式启动 MyActivity &＃xff0c;这中方式不需要在manifest.xml文件中配置&＃xff0c;直接写代码&＃xff1a;
Intent i &＃61; new Intent(this, DialogActivity.class); startActivity(i);

ok&＃xff0c;无论你采用哪种方式&＃xff0c;运行之后&＃xff0c;你可以看到如下信息&＃xff1a;
10-06 19:30:50.895: ERROR/AndroidRuntime(5789):Caused by: android.util.AndroidRuntimeException:Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want? 10-06 19:30:50.895: ERROR/AndroidRuntime(5789): at android.app.ApplicationContext.startActivity(ApplicationContext.java:550) 10-06 19:30:50.895: ERROR/AndroidRuntime(5789): at android.content.ContextWrapper.startActivity(ContextWrapper.java:248) 10-06 19:30:50.895: ERROR/AndroidRuntime(5789): at com.wpstar.receiver.ServerService.onStartCommand(ServerService.java:34) 10-06 19:30:50.895: ERROR/AndroidRuntime(5789): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2873) 10-06 19:30:50.895: ERROR/AndroidRuntime(5789): ... 10 more

明显的可以看出&＃xff1a;
10-06 19:30:50.895: ERROR/AndroidRuntime(5789):Caused by: android.util.AndroidRuntimeException:Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag.Is this really what you want?

那麽照做吧&＃xff01;修改代码&＃xff1a;
// 等效于 // Intent i &＃61; new Intent(); // i.setAction("mark.zhang"); Intent i &＃61; new Intent("mark.zhang"); // 这个不是必需的 i.addCategory(Intent.CATEGORY_DEFAULT); i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); startActivity(i);

或者&＃xff1a;
Intent i &＃61; new Intent(this, MyActivity.class); i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); startActivity(i);

也就是需要 addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)&＃xff0c;当然也可以这样&＃xff1a;


setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TOP);

关于setFlags() 方法与 addFlags() 方法可以查看源码&＃xff01;