Develop Reference

How to show the title bar in the design review?

When I am designing a layout, the design review does not show the title bar, but the simulator can show the title bar, as you can see below:
My style.xml is showing as follows:
Also, my Manifest is writen as follows:
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
Is there any ways that I can keep the title bar all the time when I design my layout? even though I create many layout file, I still hope that every layout can keep the title bar.

You need to change theme in Editor
like below image it will work

Check the current Theme in the Android Studio Design Preview :
It must not end with ".NoActionBar", you can set your theme "AppTheme".

If you are using 28 API. please change API VERSION to 26 and use this
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

AndroidManifest - Set theme for activity

I am really frustrated right now and read a ton - maybe you can help me out.
Why is Android Studio still showing me "Main2Activity" with the titlebar?
Here is my Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.martin.myapplication">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Main2Activity"
android:theme="#android:style/Theme.Light.NoTitleBar"></activity>
</application>
I know it is really a small issue but I am unable to figure it out...
Sources I used:
https://developer.android.com/guide/topics/ui/look-and-feel/themes.html
Android theme not being set
Apply a theme to an activity in Android?
EDIT
Current State:
enter image description here
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
Is working but disables the ActionBar for every Activity!
Goal: activity_main2 should not have an ActionBar.
SOLVED It is just a bug from Android Studio. In the Preview it won't disable the AppBar but as soon as you play the App on your phones it works!

To Hide the Action Bar add the below code in Values/Styles
<style name="CustomActivityThemeNoTitle" parent="#android:style/Theme.Light">
<item name="android:windowNoTitle">true</item>
</style>
Then in your AndroidManifest.xml file add the below code in the required activity:
<activity android:name=".Main2Activity"
android:theme="#style/CustomActivityThemeNoTitle"></activity>
Alternatively, you can call this.requestWindowFeature(Window.FEATURE_NO_TITLE); in the onCreate method for your activity. For example:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_signup);
...
}

Try this
<style name="generalnotitle" parent="general">
<item name="android:windowNoTitle">true</item>
</style>

Android Studio: Remove default header

I am just beginning to learn Android Studio (version 2.0, running on Windows 7). When I create a new project (Empty Activity template) Android Studio places a header at the top of the project. How can I remove the header?
Here's a picture of the problem. I want to get rid of the 'My Greeting Card' header.

You have to simply navigate like below....
app -> res -> values -> styles.xml
Find <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"> line.
Theme.AppCompat.Light.DarkActionBar line shows, how your activity will look like.
There are lots of Themes available. Just remove DarkActionBar it and press Cntrl+Space to explore another themes. In your case, you do not want Header which is called ActionBar in Android Terminology.
So, Just change theme to Theme.AppCompat.Light.NoActionBar and you are done.
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Well the answer is already given, but still i would like to add if you don't want any kind of actionbar on top of the activity simply do this.
go to your res->values->styles.xml and add these xml code
<resources>
<!-- Base application theme. -->
<style name="AppTheme.Base" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#3F51B5</item>
<!-- Light Indigo -->
<item name="colorPrimaryDark">#3949AB</item>
<!-- Dark Indigo -->
<item name="colorAccent">#00B0FF</item>
<!-- Blue -->
</style>
<style name="AppTheme" parent="AppTheme.Base"></style>
</resources>
and reference the theme in the style on any activity you want, like below in the manifest using android:theme=#style/AppTheme.
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".DetailActivity"
android:parentActivityName=".MainActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".MainActivity" />
</activity>
</application>

you can hide Toolbar using
getActionBar().hide();
or
getSupportActionBar().hide();

For Newer Version
app -> res -> values -> themes -> themes.xml
In that it also depends whether the phone is in night mode or not.
Then You have to modify both the files:
themes.xml
themes.xml (night)
with
parent="Theme.MaterialComponents.DayNight.NoActionBar"

just Remove AppCompatActivity and extend it with only Activity

ActionBarCompat, supportRequestWindowFeature(Window.FEATURE_NO_TITLE) and expected behavior

I'm uncertain of the expected behavior when using ActionBarCompat and supportRequestWindowFeature(Window.FEATURE_NO_TITLE). I see two different behaviors depending on Android version:
On a Android ICS (possibly also from Android 3.0?) device using ActionBarCompat a call to supportRequestWindowFeature(Window.FEATURE_NO_TITLE) would hide the combined titlebar/actionbar
On a Android 2.3 device the actionbar is still visible even though supportRequestWindowFeature(Window.FEATURE_NO_TITLE) is called.
Some additional information: My activities extend android.support.v7.app.ActionBarActivity and my app uses the #style/Theme.AppCompat.Light theme. supportRequestWindowFeature(Window.FEATURE_NO_TITLE) is called before setContentView(). I never make any call to either getSupportActionBar().show() or hide().
So, what's the expected behavior? When I used ABS a call to requestWindowFeature(Window.FEATURE_NO_TITLE) would hide the titlebar/actionbar regardless of Android version.
How would I go about having an android app where some activies use an actionbar while others have none? Should they not extend the same base class?

So I've found a solution to this but it uses styles applied via the AndroidManifest (and therefore needs no code). Keep in mind that this will almost definitely only work if you're using the AppCompat library.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="..."
android:versionCode="1"
android:versionName="1.0">
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="19" />
<application
android:allowBackup="false"
android:icon="#drawable/launcher"
android:label="#string/app_name"
android:theme="#style/Theme.AppCompat.Light.DarkActionBar">
<activity
android:label="#string/log_in"
android:name=".activities.LogInActivity"
android:parentActivityName=".activities.MainActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".activities.MainActivity" />
</activity>
<activity
android:label="#string/app_name"
android:name=".activities.MainActivity"
android:theme="#style/Theme.AppCompat.Light.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:label="#string/sign_up"
android:name=".activities.SignUpActivity"
android:parentActivityName=".activities.MainActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".activities.MainActivity" />
</activity>
</application>
</manifest>
Note how I've got a global theme applied directory to the <application> tag, and then also a theme that's individually applied to my MainActivity class through its own <activity> tag. That is the only Activity where I want the Action Bar to be hidden; everywhere else I want it to be visible (which is why I don't have individual themes applied to any of my other Activities as I instead let them inherit from the global application theme).
But you'll quickly find that Theme.AppCompat.Light.NoActionBar doesn't actually exist. This is because I had to create that style myself, which requires two different styles.xml files:
values/styles.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.AppCompat.Light.NoActionBar" parent="Theme.AppCompat.Light">
<item name="windowActionBar">false</item>
<item name="android:windowNoTitle">true</item>
</style>
</resources>
values-v11/styles.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.AppCompat.Light.NoActionBar" parent="Theme.AppCompat.Light">
<item name="android:windowActionBar">false</item>
<item name="android:windowNoTitle">true</item>
</style>
</resources>
You must use two different styles.xml files for this as the android:windowActionBar flag didn't exist before Android API version 11.

Theme not being applied

I am simply trying to change the background color for an activity, however nothing has changed.
Here is the relevant XML:
styles.xml
<resources>
<style name="STBTheme" parent="android:Theme.Light" >
<item name="android:windowBackground">#color/blue</item>
</style>
</resources>
AndroidManifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.pedro.stb"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="15" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/STBTheme" >
<activity
android:name=".MainActivity"
android:label="#string/title_activity_main"
android:theme="#style/STBTheme" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Furthermore, I'm using Eclipse, and by changing the theme in the activity's xml, it does not change in the graphical layout.
Any help?
Edit
Got it to work. Have to clean the project before reloading the layout. Very annoying...

i had check your code its ok .
try <item name="android:Background">#ccff33</item>
instead of your <item name="android:windowBackground">#color/blue</item>.
and you have write android:theme="#style/STBTheme" > in application as well as activity also.
Just write in application tag .
Hope you will get your output now.

Open the preview of your activity and Click on the circled button as shown
Type the name of your custom theme and Click 'OK' as shown
In Manifest file add the attribute android:theme=".YourTheme" to the required Activity
You will have the theme of the current activity changed.
I dont know why Android Studio acts like it's drunk sometimes. I have two projects with same target,minimum SDK active. One of them had the splash screen theme implemented correctly, the other just wont show until I found this workaround.