I know that there are some similiar questions to this one but I've tried the suggestions that I found in the asnwers but none of them worked for me so I decided to publish my version of the problem.
I'm using this android studio project https://github.com/rosjava/android_core that has multiples modules inside as you can see. I had another project that I had to import to this android_core one so I downgraded its graddle version, since the version was more updated, and added it as an imported module.
After I fixed some building problems I got the "Default Activity not found" error which seemed odd to me since I had an activity marked to be the default activity so either way I decided to add it here too:
The next warning is the one on the bottom of the image which, once again, sounds odd to me since I had everything declared in the oringal project's AndroidManifest.xml file it's exactly the same on this one:
I have tried re-building, Invalidating Cache/Restarting and deleting and re-extend the AppCompactActivity class but nothing seems to work.
What am I missing? Thanks in Advance!
In the root of the manifest xml should be a manifest node with an attribute package. Make sure that the package 'com.example.prj_' is the value.
Then in your activity node you only have to place the value '.MainActivity'. Otherwise you can get some build errors for the resources in the R class.
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.prj_">
<application
...>
<activity
android:name=".MainActivity"
...
</activity>
</application>
</manifest>
Add .MainActivity to your Android Manifest file.
<application
...>
<activity
android:name=".MainActivity"
...
</activity>
</application>
There are apparently race conditions with background computation of the merged manifest vs. automatic checks of it. The workaround would be to open AndroidManifest.xml and click on Merged Manifest, this forces the merge. Then clicking Run should pass the automatic tests.
See also https://issuetracker.google.com/issues/158019870
There are some ways to clean a project for removing this error.
1- File-> Sync Project with Gradle Files
2- Files -> invalidate cache / Restart
3- android:name=".MainActivity" --> android:name="com.example.prj.MainActivity"
I've been having this problem since upgrading to Android Studio 4.0 on macOS. When I try to start my app from Android Studio, I get the following error:
Could not identify launch activity: Default Activity not found
Error while Launching activity
What's a bit unique about my project is that the default activity is defined in the manifest of another library used by my project, not the project itself. This was all working fine before the upgrade, but now it isn't for me. When I open the project containing the dependency, it builds and runs fine. I've already tried the following steps:
clean the project, rebuild
invalidate caches and restart
reinstall Android Studio
delete all generated files and folders (build, gradle, .idea, etc)
You can solve the problem as follows:
Click your Module Selection window，then click Edit Configurations…
Then set Launch Options to Nothing; that's okay：
To dovetail off of Mike N.'s comment, it looks like it is an issue to be resolved in the next point release: https://issuetracker.google.com/issues/158019870
For the details of the quick fix, for me I looked at the Merged Manifest tab, which is at the bottom-left of the AndroidManifest.xml pane. This shows all of the library manifests combined with your activity's.
The dialog said an error occurred where browser:1.0.0 manifest had a minSdk of 15 whereas all the rest of my minSdk are 14. I clicked on:
use a compatible library with a minSdk of at most 14, or increase this
project's minSdk version to at least 15.
Which brought up my minSdk to 15, and the error with the launcher went away, it will now insta-launch on my device. So I would sit tight for AS 4.0.1 but in the meantime, check the Merged Manifest.
For me this was happening in a project in which the main activity was declared in the manifest of an imported module (e.g. not in "app" module).
The solution for me was to add again the activity declaration in the manifest file of my top project:
<activity android:name="com.cristian_slav.elements.MainActivity"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
On my side it was a issue with the manifest. You can detect this type of issue by watching the merged manifest tab. For more details you can watch the link shared by Mike N. in the first comment.
The problem will arise in new projects when one forgets to tick the default activity checkbox during adding anyone of the first or subsequent new activity.
This can be rectified at later stage by going to Run> Edit Configurations > Launch : in which change to specified activity and select the activity you choose to keep as the first page on launch of app.
Try these steps:
Close Android Studio
Go to
C:\Users\my_user_name.AndroidStudio4.0\system\caches
Delete "caches" folder
Relaunch Android Studio
set Launch Options to (Nothing)
I'm using Android Studio 1.4
It has passed some time since the last time I've created a new project in android studio and today when I did it the android studio does not show anything from the layout preview. Its a blank window and says "Nothing to show".
I think it's related with the new support design library cuz I've never seen this new "default code". I've researched a bit and it's the new android material design guidelines ...
I've already done this:
updated the SDK tools
cleaned the project and rebuild it
invalidated and restarted caches
...and still nothing.
Updated:
I decided to update 1.5.1 it's like this: it's giving me that rendering problem.. I think it's not showing correctly the lower right button, cuz I think it's supposed to be a button with a message icon in it and in my AS just shows the message icon (correct me if I'm wrong).
Choose another theme (other than Holo, for example Theme)
When you create the style incorrectly or from an existing style, this problem usually occurs. So select the "Graphical Layout" select "AppTheme" (The tab with a blue star). And select any of the predefined style. In my case "Light" which should resolve the problem.
Try to 'Invalidate caches & restart'.
Restart your Android Studio by choosing this option. It may take some time.
Then, if still doesn't work try to rebuild your project.
This is a common problem . It can be easily solved by changing res/values/styles.xml to
<!-- Base application theme. -->
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
</style>
Steps :
Go to res/values/
open styles.xml
change from -> style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"
change to -> style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar"
(Just prepend "Base." to "Theme".)
Save the file and check Preview now.
Preview Works Perfeclty now.
Force refresh helped me.
It is at the top of the design tab.
Check again for SDK update because API 23: Android N (preview) is now available, download it properly OR select the API 23: Android 6.0 from the top right of the preview window. check the image
.
.
It (Android Studio) automatically selects the latest one even if it not properly installed. So,
What you need to do is :
install the new one properly
OR
click on the previous one.
Find Styles.xml in Values.(res/Values/Styles.xml)
Change this
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
to this:
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
Then clean and build project. Both of those you can do from build menu.
It worked for me.
Clean build your project by going to Build > Clean build.
It helped me when I had the same problem.
I also go through same problem and do this simple work just go to res->values->style.xml and change
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
to
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
Fast Forward to 2018 and we are still having this issue!
When I had this issue with Android Studio Canary 3.2 today, this is what I did:
I went to
File -> Settings -> Plugins
On the plugins list, I disabled Android Support by unchecking it.
Then, I selected Apply and then, OK.
After this I restarted Android Studio.
On restart, I repeated the process:
File -> Settings -> Plugins
But this time, on the plugins list, I enabled Android Support by checking it.
Then I restarted.
When Android Studio came on, I allowed Gradle do its thing, then I did:
File -> Sync Project with Gradle Files
When this was done, I reopened my xml files or refreshed them anyhow possible
and everything was fine.
Yeah long route, but on a day when I have to deliver at work? It sure works!
TLDR: Just disable and re-enable Android Support and you will be fine
Sometimes layout preview not show only in your current project, try open other project if in other project layout preview work well then the problem in your current project.
in your current project try clean project, rebuild project, if still not working try make changes in your build.gradle app file, such add some implementation then gradle sync , check your layout preview works.
Switch from Blank Activity and use Empty Activity. Change your theme to for example Holo.Light.NoActionBar.
Unlike Blank, Empty is more stripped down thus you may need to add some stuff yourself. Such as add the 2 Override methods onCreateOptionsMenu and onOptionsItemSelected yourself if you need to manipulate controls on the ActionBar and such. Otherwise, no other significant difference.
I faced the exact problem when creating a new project, It seams to be related to the Appcompat Library to solve it:
I replaced : implementation 'com.android.support:appcompat-v7:28.0.0-alpha3' by implementation 'com.android.support:appcompat-v7:27.1.1' And everything worked fine.
In conclusion, The problem is related to a bug in the library version.
But if it is necessary to use the Natesh bhat's solution is for you.
In my case, Android Studio created project including support library which version is RC or beta.
So I tried downgrade version of support library, then worked.
If your library version is RC or beta, try downgrade.
Downgrade this
implementation 'com.android.support:appcompat-v7:28.0.0-rc01'
to this
implementation 'com.android.support:appcompat-v7:27.1.1'
and downgrade also compileSdkVersion, targetSdkVersion if you need.
This problem occurs due to theme compatibility issue.
All you have to do is first navigate to res/values/styles.xml in the project view.There look for base application theme which by default should be the fourth line.
It'd look similar to the following:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
Now, you just have to add 'Base. to the parent.
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
If the project contains multiple themes, it should be ensured that the right theme is selected in the 'Theme for preview' option.
In android studio dolphin, it would look something like this:
It doesn't even show the "Hello World" in the preview when i started my first project,only displays 'Rendering problem' and 'Failed to instantiates one or more class'.This helps me out, try this.....
in the left side menu, GoTo
base-> res-> values-> styles.xml
then write "Base." in the line <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
just before the Theme.AppCompat i.e <style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
just refresh your layout by clicking this:
there will be a blue logo at the top left of the "layout-design" page
click and choose "Force Refresh Layout"
In your top Android Studio menu, go to View > Tool Windows > Preview, then it should appear somewhere in the frame of Android Studio, you can move it to the desired place with the dented wheel tool in the Preview frame
For me, in Android Studio 3.6.1, while in the layout.xml file, clicking here showed the preview of the layout again.
I Don't think the "tab" Preview exists anymore, it does now appear to me here: View > Tool Windows > Preview.
Change the Android version to use while rendering layouts in the IDE.
Go to your xml layout file -> Design -> change Android API version from Automatically Pick Best to a value in between your minimum and target sdk versions.
use the below code in build.gradle and it will show your layout preview.
configurations.all {
resolutionStrategy {
force 'androidx.core:core-ktx:1.6.0'
}
}
Please (change com.android.support:appcompat-v7:28.0.0-alpha3) or (com.android.support:appcompat-v7:28.0.0-rc02) to (com.android.support:appcompat-v7:28.0.0-alpha1) in build.gradle (Module: App).
Next click File -> Invalidate Caches / Restart
Need internet access.
It works for me Windows 10 and in Ubuntu 18.04.1 LTS
Clean Project
Rebuild Project
Invalidate Caches / Restart
Android Studio Stuck At Initializing
Close the project
Delete .idea folder in project root folder
Open the
project
Here is a simple solution that worked for me:
Go to File -> Settings -> Apperance & Behavior -> System Settings -> Android SDK :
Check Show Package Details which is located on the bottom right.
Under the latest Android SDK version (for ex: Android 8.1 (Oreo)), check Google Play Intel x86 Atom System Image
Now click apply button
This system image helps android studio to show layout preview.
Changing the theme(near the android symbol for changing API version) from AppTheme to anything else like DeviceDefault or Holo fixed the problem easily.
After so many flip-flap I realised that on xml Preview size above,on the left side of Apptheme we have Android Icon with ears click it and change to your target api in case that its not the same as it targeted on built.gradle
For me this problem keeps appearing after I run the APK at first time. Invalidating did not help.
However, I came with a workaround:
Just run the APK, and while it's running you can submit your changes clicking the "Lightning" button (Apply changes) next to to the "Run" button at the top right panel. Works charming for me, when making changes to the layout.
Follow a few steps:-
1) Clean Project
If 1 doesn't work then
2) Invalidate cache and restart
If 2 doesn't work then
3) run command in the project folder rm -r .idea
Android Studio Stuck At Initializing
android studio 4.1.2 suddenly stuck at initializing preview and XML preview is completely crashed. this is what I have done to fix the issue
go to C:/Users/username/AppData/Roaming/Google
Delete the entire AndroidStudio folder
Invalidate cache and restart your IDE
SOLUTION
Go to Preferences -> Plugin -> Installed.
Search "Android APK Support" -> Disable it
Invalidate Caches & Restart
Re-enable "Android APK Support" plugin
Restart
Done (It should resolve the issue. If you still see the issue on some custom views, just rebuilt/run the project)
PROBLEM
The reason of the issue (from my investigation) is related to some incorrect UI parts, for example:
Incorrect XML layout implementation
Incorrect styles implementation
So if the issue still persists, just try to figure out what part of your UI implemented wrong, and fix it.