Develop Reference

how to declared an activity in AndroidManifest.xml?

Class referenced in the manifest, se.linerotech.myapplication.RepositoryActivity, was not found in the project or the libraries
this is my first app ever (github browser),am copying the steps from a video and when i tried to debugg my app to see if i was getting the data for user it crashed
i tried to redo the steps and go over everything i did but it didnt work

Just to be clear, you have two different errors in those screenshots.
The one in the manifest is saying it can't find the Activity class with that name, for the reason outlined in CommonsWare's answer - it's looking for se.linerotech.myapplication.RepositoryActivity, and that's not where your class is. It's in red because it's an unrecognised name/not found.
The other error is in the output window - it's saying you have an Activity class at se.linerotech.myapplication.acitvity.RepositoryActivity which hasn't been added to the manifest. This is true (you tried adding it, but didn't do it right) and every Activity needs to be included in the manifest, which is why it's complaining.
The two errors stem from the same issue, I just wanted to make it clear what each one means, since if you just looked at the error log you might think you've used the correct fully-qualified name for the class (it's right there in the output!). But it's two different sides complaining about the same thing for different reasons.

Class referenced in the manifest, se.linerotech.myapplication.RepositoryActivity, was not found in the project or the libraries
That is because you do not have a class with that fully-qualified class name.
Your class is se.linerotech.myapplication.activity.RepositoryActivity, because it resides in the se.linerotech.myapplication.activity package. Use se.linerotech.myapplication.activity.RepositoryActivity instead of .RepositoryActivity in your manifest.

error: the method ´flatbutton´ isn´t defined for the class

recently I realized that there was a flutter update, I am trying to debug an app that I have tested before, right now the console throws me the following errors:
here is a screenshot of my error
error: the method ´flatbutton´ isn´t defined for the class
I am a newbie in flutter please if someone could help I would appreciate it

FlatButton was deprecated and in the new Flutter version you should use TextButton or OutlinedButton to replace it

A new set of basic material button widgets and themes have been added to Flutter. The original classes have been deprecated and will eventually be removed. The overall goal is to make buttons more flexible, and easier to configure via constructor parameters or themes.
See docs for more info and the New Widgets to use.

MEDIA_PROJECTION_SERVICE not valid in call to getSystemService()

I am trying to develop an application that requires the ability to capture screen content. I'm targeting lollipop to avoid the requirement for root. When trying to get an instance of the MediaProjectionManager via a call to getSystemService() I am getting the following error reported in Android Studio:
Must be one of: Context.POWER_SERVICE, Context.WINDOW_SERVICE, Context.LAYOUT_INFLATER_SERVICE, Context.ACCOUNT_SERVICE, Context.ACTIVITY_SERVICE, Context.ALARM_SERVICE, Context.NOTIFICATION_SERVICE, Context.ACCESSIBILITY_SERVICE, Context.CAPTIONING_SERVICE, Context.KEYGUARD_SERVICE, Context.LOCATION_SERVICE, Context.SEARCH_SERVICE, Context.SENSOR_SERVICE, Context.STORAGE_SERVICE, Context.WALLPAPER_SERVICE, Context.VIBRATOR_SERVICE, Context.CONNECTIVITY_SERVICE, Context.WIFI_SERVICE, Context.WIFI_P2P_SERVICE, Context.NSD_SERVICE, Context.AUDIO_SERVICE, Context.MEDIA_ROUTER_SERVICE, Context.TELEPHONY_SERVICE, Context.CLIPBOARD_SERVICE, Context.INPUT_METHOD_SERVICE, Context.TEXT_SERVICES_MANAGER_SERVICE, Context.DROPBOX_SERVICE, Context.DEVICE_POLICY_SERVICE, Context.UI_MODE_SERVICE, Context.DOWNLOAD_SERVICE, Context.NFC_SERVICE, Context.BLUETOOTH_SERVICE, Context.USB_SERVICE, Context.INPUT_SERVICE, Context.DISPLAY_SERVICE, Context.USER_SERVICE, Context.PRINT_SERVICE less... (Ctrl+F1)
Reports two types of problems:
* Supplying the wrong type of resource identifier. For example, when calling Resources.getString(int id), you should be passing R.string.something, not R.drawable.something.
* Passing the wrong constant to a method which expects one of a specific set of constants. For example, when calling View#setLayoutDirection, the parameter must be android.view.View.LAYOUT_DIRECTION_LTR or android.view.View.LAYOUT_DIRECTION_RTL.
I am currently at a loss as to why this constant is not considered valid, it's there as an autocomplete option, so it's present, and it's shown in all sample code I have seen for screen capture in lollipop. I have verified that the project setup specifies Android SDK 21 as min and target. Is there something else obvious/stupid I might be missing that would cause this error?
UPDATE: Took the exact same code to Eclipse and it works without issue. So this is related to something in Android Studio specifically it seems.

I get this error while getting Context.BLUETOOTH_SERVICEand the error doc (Must be one of..) contains Context.BLUETOOTH_SERVICE though.
This is not the way Android Studio "1.2" should work. :#
Anyway, its an Inspection bug, Constant and Resource Type mismatch (How in the hell Bluetooth is a resource in android context).
You can suppress this for Class/Method/Statement, for statement, add #SuppressWarnings("ResourceType") above or before the statement.
Another approach:
Goto Settings>>Editor>>Inspection>>Android>>Constant and Resource Type Mismatches and make the severity to anything but Error, probably Warning or Weak Warning.
(Though it fixes the error issue, but I want this mismatch to be an error when it really happens.)

Run into the same problem, it is so strange, there are no any other threads talking about this problem.
Well, actually you can just ignore this error and still run the program, even with
the red marks on it

AndroidAnnotations cannot find symbol class

I'm using AndroidAnnotations in an Android Studio gradle project. I currently get error output from AA during compilation that says:
cannot find symbol class MyActivity_
The error output does not prevent building the application - its not really a compile error because the class is there, it seems that it is just an unfortunate timing issue with the compilation process.
Is there anything I can do to avoid these false-positive errors from AA? When there are "fake" errors shown every time I compile, its very easy to miss the real errors.

I had same error. To solve it I have revert my last changes and it has worked again.
I think it was either wrong optimized import(you must import generated classes eg. xxx_) or I injected layout by id what was not existed in the layout xml
Update
I figured it. My problem was what I had use private mofidier instead of proteced in
#ViewById(R.id.list)
private ListView list;

Try to see if you missed to fix some errors in the class MainActivity or in someone of his Bean member that you have annoted.

The problem doesn't have to be in MainActivty, but it is probably because of a private modifier which is used with Android Anotations (in injection, method declaration etc) somewhere in your code

Add enclosing class to Eclipse template

I do many logging in Android, so I want to create an Eclipse template for quick logging. This is my template :
Name: log
Pattern: Log.d("${enclosing_package}", "${enclosing_method}" +${cursor});
I need to add enclosing class to log info but there is no $enclosing_class. Is there any way to get enclosing_class?
Thanks!

You want ${enclosing_type}.
The complete list of template variables is available in Eclipse help.