获取栈顶Activity与判断是否有网络

1、获取栈顶Activity

public static String getTopActivity(Context context) {
android.app.ActivityManager manager = (android.app.ActivityManager) context.getSystemService(context.ACTIVITY_SERVICE);
List<ActivityManager.RunningTaskInfo> runningTaskInfos = manager.getRunningTasks(1);

if (runningTaskInfos != null) {
return (runningTaskInfos.get(0).topActivity).toString();
} else
return null;
}

注：1、获取到的string字符串，包含的是 com.a.Activity，所以，拿到这个字符串以后，要判断当前activity是否是处于栈顶，需要用 contains方法

2、加权限：

<uses-permission android:name="android.permission.GET_TASKS" />

2、判断有无网络

// 是否有网络，包括2g,3g.wifi
public static boolean isNetActive() {
boolean flag = false;
ConnectivityManager manager = (ConnectivityManager) UIUtils.getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
if (manager.getActiveNetworkInfo() != null) {
flag = manager.getActiveNetworkInfo().isAvailable();
}
return flag;
}