How to specify which OS build I wish to do - flutter

Flutter 3.0 is amazing !!
I can make a web app, android & iOS mobile app, and a native Mac app (and more) all from the one code base.
But now my problem is :
How do I specify which OS to build-for and run-on ?
When I do flutter run or debug>run in VSCode it will build-for, and run-on, my Android device first if it plugged in, or else as a Mac app. I want to run it as Web. More generally, I want to specify which OS I want to build and run for.
Both the flutter run command line option, and the VSCode setting (preferably without messing about with launch.json, or else making that seem easy).

You can use
flutter run -d chrome
For running it on chrome
flutter run -d your_device
For mobile device

It depends on the selected device. If you select an Android Device, it will build for Android OS. If you select a browser then it will run the build on your Default Browser and the same goes for other scenarios.

Related

How do I remove devices for running Flutter?

I tried creating a new flutter project in Visual Studio Code, but for whatever reason it now has a default device of Google Chrome every time I try to run it. I don't want to run Flutter in web environments whatsoever: is there any way I can disable this?
Run the following command to disable web completely.
flutter config --no-enable-web
Then restart your editor if necessary.
First, run your emulator from the AVD manager or connect your physical device while it's on debugging mode, if it's an android device, then choose the device you want to run from the flutter device selection option

How to `flutter run` with target device as android?

I have my flutter app built and running on macOS using the following command.
flutter run
This is great.
Now, I want to run my app on an Android device. It has developer mode enabled and getting recognised when I run adb devices. I have also run other apps on my Android device. So, I am sure the android device is well set for android development.
But now when execute flutter run, my app still runs on macOS instead of Android device. I did a flutter build apk which built my app for android. But, flutter run still runs on Mac instead of Android.
Isn't there a flutter run command to run the build on Android specifically?
flutter -v -d your_android_device run selects the target device to run on.
Check that your device is recognized using flutter devices (or flutter doctor -v). If so, you can specify the device id you using flutter run -d <deviceID>.
flutter -d 54XXXXXX35130ebefd38f run

how to run flutter app in VSCode without android studio emulator

I want to run flutter app in VS.Code without android studio emulator.
I want run my app without install android studio.
How can I do this?
If you have Gradle properly installed globally (https://gradle.org/install/) and the Android SDK setup on your machine, then you should not need the IDE.
Try first checking for available devices:
flutter devices
Then using the device that you find (if there are any spaces in the name that represents the device then use "" to format the command), execute the following command:
flutter run -d "Device Name With Spaces" --release
Or:
flutter run -d DeviceNameWithoutSpaces --release
The first option is You can run your application on chrome or edge if you don't want to download an emulator. Follow the following steps:
Click on the no-device option to select the device.
Now select chrome or edge
And the second option is you can connect your mobile with your PC and use your phone to run the flutter apps. Follow the following steps:
For Android:
Enable developer options and USB Debugging on your device. This varies slightly
by android version. But the short version is you tap on the device build number
7 times.
Then a “Developer Options” option comes up. After that, you can click “enable
USB Debugging.”
Then plug your phone into your computer with a USB cable. You’ll see some popup
on your phone asking if you want to allow USB debugging with that computer.
Click on “yes”.
Run Flutter just like you would if you had a simulator running.

How to launch Hello World Flutter on Desktop from Android Studio?

I am trying out flutter value proposition of multi platforming.
I am on Android Studio.
Hello world works on Android.
Hello world is not launched on Iphone Emulator even though it is shown in the drop down.
I don't see anything to launch the app in a desktop where i can resize the window at will
I don't see anything either to launch the app in the browser.
Any help? Especially for the desktop and web .. The iphone emulator is probably a setting.
I am on Android Studio 3.3.2 and XCode 10.1
Flutter for desktop is in very early stages, as described on the Flutter wiki; it won't work out of the box. If you want to experiment with it, you'll need to manually add desktop support to your project.
Similarly, Flutter for web is a technical preview that requires extra setup to try out.

Message "flutter run: No connected devices"

I am trying to create a sample application with Flutter (fresh installation). Android Studio is also installed (fresh installation).
Here is the output of flutter run
flutter run
No connected devices.
The output of flutter doctor:
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v0.1.5, on Linux, locale en_US.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
[✓] Android Studio (version 3.0)
[!] VS Code (version 1.20.1)
[!] Connected devices
! No devices available
! Doctor found issues in 2 categories.
Is there a solution to this problem?
Flutter supports both iOS and Android device/simulators.
In the terminal, run the flutter devices command to verify that Flutter recognizes your connected Android device.
Here is a reference document on how you can set up a device/simulator to run your application.
For, Android (on a Mac system)
Set up your Android device
To prepare to run and test your Flutter app on an Android device, you’ll need an Android device running Android 4.1 (API level 16) or higher.
Enable Developer options and USB debugging on your device. Detailed instructions are available in the Android documentation.
Using a USB cable, plug your phone into your computer. If prompted on your device, authorize your computer to access your device.
In the terminal, run the flutter devices command to verify that Flutter recognizes your connected Android device.
Start your app by running flutter run.
By default, Flutter uses the version of the Android SDK where your ADB tool is based. If you want Flutter to use a different installation of the Android SDK, you must set the ANDROID_HOME environment variable to that installation directory.
Set up the Android emulator
To prepare to run and test your Flutter app on the Android emulator, follow these steps:
Enable VM acceleration on your machine.
Launch Android Studio → menu Tools → AVD Manager and select Create Virtual Device.
Choose a device definition and select Next.
Select one or more system images for the Android versions you want to emulate, and select Next. An x86 or x86_64 image is recommended.
Under Emulated Performance, select Hardware - GLES 2.0 to enable hardware acceleration.
Verify the AVD configuration is correct, and select
Finish.
For details on the above steps, see Managing AVDs.
In Android Virtual Device Manager, click Run in the toolbar. The emulator starts up and displays the default canvas for your selected OS version and device.
Start your app by running flutter run. The connected device name is Android SDK built for <platform>, where platform is the chip family, such as x86.
Here is another document, if you're using (Microsoft) Windows System: Get Started: Install on Windows
Open & Connect Device using Android Studio:
Here is an easier way to open and connect simulators/devices.
Android Studio shows a list of emulators/simulators (installed in your system) or devices (connected to your system). Just select a device you want to open from a list, and run the project.
Use:
flutter config --android-sdk ANDROID_SDK_PATH
Or
Device Not Found (when setting up Flutter in Android Studio)
Project structure -> select latest Android API in Project SDK
This was my solution:
My "Developer Options" was ON, but the "USB Debugging" was OFF.
So I turned ON the USB Debugging and the problem was solved.
None of the suggestions worked until I ran:
flutter config --android-sdk ANDROID_SDK_PATH
Use "ANDROID_SDK_PATH" = your path. For example:
flutter config --android-sdk C:\Users\%youruser%\AppData\Local\Android\Sdk
I solved the AVD problem with Flutter using the Flutter console.
Step 1:
C: \ Users \ valer> flutter emulators
6 available emulators:
3.2_QVGA_ADP2_API_22 _-_ Lollipop • 3.2in QVGA (ADP2) • Generic • 3.2 QVGA (ADP2) API 22 - Lollipop
Android_ARMv7a
Android_Accelerated_x86
Nexus S API Google Nexus S API 23
Nexus_S_API_25_1080x1920_Nougart_7.1.1_ • pixel • Google • Nexus S API 25 1080x1920 (Nougart 7.1.1)
Pixel_API_28 • pixel • Google • Pixel API 28
To run an emulator, run flutter emulators --launch <emulator id>.
Step 2:
C: \ Users \ valer> flutter emulators --launch Pixel_API_28
In my case
Menu File → Project Structure
Select the latest SDK:
I encountered the same problem as you did. It turns out that your device is not connected with your computer.
Note:
If you are using Xcode, if both your computer and the device are using the same Wi-Fi AP, you don't have to connect the device with the computer.
For Android, or iOS running under terminal command, if you are using command line to run this, you have to make sure they are connected via cables. Sharing the same Wi-Fi AP does not work. Make sure your device is really connected.
Make sure you allowed USB Debugging on your Android device.
If this still does not work, try to fire the below command, where you can get richer information and details:
flutter run --verbose
What I needed to do:
flutter emulators
It will list all available emulators. For iOS you will need to open the simulator first.
flutter emulators --launch EMULATOR NAME
This will launch the emulator.
And to build it:
flutter run -d "EMULATOR ID"
I ran mine with Genymotion, probably the best for Flutter.
Setting up is less painful, but make sure setting ADB under:
Your Andouird SDK path
Mine is C:\Users\user\AppData\Local\Android\Sdk.
I am using Linux and here are the steps that can help. First open Android Studio with root permissions, (Windows: Right-click the program icon → Choose Run As Administrator, Linux: sudo ./studio.sh in the terminal)
Create emulator with Hardware - GLES 2.0 in hardware acceleration as mentioned here. Open a terminal in Android Studio (Alt + F12).
Run command flutter devices and see the list devices:
root#abc-OptiPlex-3050:~/flutter_workspace/my_app/my_app# flutter devices
Woah! You appear to be trying to run flutter as root.
We strongly recommend running the flutter tool without superuser privileges.
1 connected device:
Android SDK built for x86 • emulator-5554 • android-x86 •
Android 8.1.0 (API 27)(emulator)
Finally run flutter run from the terminal:
root#abc-OptiPlex-3050:~/flutter_workspace/my_app/my_app# flutter run
Woah! You appear to be trying to run flutter as root.
We strongly recommend running the flutter tool without superuser privileges.
Using hardware rendering with device Android SDK built for x86.
If you get graphics artifacts, consider enabling software rendering
with "--enable-software-rendering".
Launching lib/main.dart on Android SDK built for x86 in debug mode...
Initializing gradle... 0.7s
Resolving dependencies... 1.2s
Running 'gradlew assembleDebug'... 1.5s
Built build/app/outputs/apk/debug/app-debug.apk.
I/FlutterActivityDelegate(25096): onResume setting current activity to this
Syncing files to device Android SDK built for x86...
D/ (25096): HostConnection::get() New Host Connection established
0xe8487780, tid 25116
D/EGL_emulation(25096): eglMakeCurrent: 0xe5b3d8a0: ver 2 0 (tinfo 0xe84832f0)
🔥 To hot reload changes while running, press "r". To hot restart (and
rebuild state),press "R".An Observatory debugger and profiler on
Android SDK built for x86 is available at: http://127.0.0.1:8100/
For a more detailed help message, press "h". To quit, press "q".
And do check the flutter-sdk path in your project.Configure file from this answer.
Set Project SDK of project from Project Structure
File > Project Structure > Project SDK > "available sdk" > Apply
Sometimes you have everything perfect, but the device is no longer authorized on ADB. In such cases you have ADB, but it will not show you in connected devices.
Steps to fix this issue
1. Check if authorized:
Open terminal/cmd/PowerShell and write adb devices. It will show you all connected devices to the PC.
<ANDROID_SDK_HOME>\platform-tools>adb devices
List of devices attached
4df798d76f98cf6d unauthorized
2. Revoke USB debugging on the phone
If the device is shown as unauthorized, go to the developer options on the phone and click "Revoke USB debugging authorization" (tested with Android 4.1 (Jelly Bean) and Samsung Galaxy S III).
3. Restart ADB Server:
adb kill-server
adb start-server
4. Reconnect the Device and run following command again: adb devices
Now it should display authorized.
5. Ready to go.
Now, open your editor, Android Studio or Visual Studio Code, and check if your device is showing in connected devices or not.
You can simply check that with the flutter doctor command.
For Windows users,
Set the environment variable PATH for the Flutter SDK (...\flutter_windows_v0.2.8-beta.zip\flutter\bin)
No device connect
For more information, you can check blog post Flutter - How to install Flutter in Android Studio
Here is the information from the mentioned page:
Add Flutter to the Windows environment variable PATH:
Navigate in to the Flutter SDK folder.
Go inside the bin folder and copy the directory path (in your case C:\Flutter\bin)
Go to “Control Panel > User Accounts > User Accounts > Change my environment variables”
Under “User variables”, select the PATH variable and click Edit.
Put C:\Flutter\bin and apply.
Same as the Flutter environment, we have to set the Android SDK path if it is on custom location.
Navigate into the Android SDK folder.
Copy the directory path (in your case ..AndroidStudioSDK\sdk)
Go to Control Panel* → User Accounts → User Accounts → Change my environment variables
Under “User variables” select the PATH variable and click Edit.
Enter ..AndroidStudioSDK\sdk with ANDROID_HOME and apply.
Tips:
If you facing the following issue,
1.[✗] Android toolchain - develop for Android devices
✗ Unable to locate Android SDK.
Install Android Studio from https://developer.android.com/studio/index.html
On the first launch, it will assist you in installing the Android SDK components.
(or visit https://flutter.io/setup/#android-setup for detailed instructions).
If Android SDK has been installed to a custom location, set $ANDROID_HOME to that location.
You can resolve it with the following command.
flutter config --android-sdk <android-sdk-location>
OR
flutter config --android-sdk "android-sdk-location"
Error: Unknown argument --licenses
You can resolve it with the following command.
flutter -v doctor --android-licenses
Now, pick the emulator you want to use and click the green arrow to run the project. So, here default screen that is already designed.
I am facing the same issue with Flutter. But I found another way to work, i.e.,
First run Android Emulator
Then go to your Flutter Console
Run the command flutter doctor, anf check whether your emulator is showing under connected devices tag, e.g.,
Now move to your Flutter project path via the Flutter console. E.g., for me it is D:\FlutterWorkspace\flutter_demo
Then run the flutter run command. E.g.,
Wait for few moments. You will see your app running in the Android Emulator.
If you have
Downloaded the Flutter SDK
Connected your mobile device and enabled the developer option on the mobile and allowed USB debugging.
And if you are still getting "No device connected" then I think you should install the ADB driver.
It worked for me!!
Click here to download
There should be at least one device/simulator connected to run Flutter applications.
Also make sure the USB debugging is enabled in developer settings.
One option that I haven't see mentioned so far is that (for my setup) the Developer Option 'Select USB Configuration' must be set to MTP (Media Transfer Protocol).
The actual answer did not work for me.
But setting ANDROID_HOME in your ~/.bash_profile file, logging out, and then logging in, makes it work!
This may be an Android Studio issue since it is not setting this environment variable for the open projects.
Follow these step:
Menu File -> Project Structure -> Project SDK(Select the SDK Path in the Android SDK) -> OK
Make sure your device is connected to the PC.
Open Git Bash and type:
flutter devices
Then run your Flutter app. It will work.
Android Studio -> Preferences -> Languages & Frameworks -> Dart
Make sure you enabled Dart support for the module (should be checked in)
I had the same problems while I was debugging with a local Flutter engine. In such case, if you have set environment variable FLUTTER_ENGINE, you should unset it and restart you IDE.
Step 1: To check the connected devices, run: flutter devices
Step 2: If there aren't any connected devices to see in the list of available emulators, run: flutter emulators
Step 3: To run an emulator, run: flutter emulators --launch <emulator id>
Step 4: If there is no available emulator, run: flutter emulators --create [--name xyz]
==> For Android:
Step 1: To check the list of emulators, run: emulator -list-avds
Step 2: Now to launch the emulator, run: emulator -avd avd_name
==> For iOS:
Step 1: open -a simulator
Step 2: flutter run (in your app directory)
Flutter needs a device to run the app. There are two choices for this.
Run the app on your real phone.
Run the app on a virtual device in your computer.
I would recommend Option 1 because it doesn't use your device resources and is faster.
Option 1:
Unlock developer options on your phone, go to developer setting and turn on USB debugging and connect your phone to your computer. Now run flutter run and it will work.
Option 2:
Open Android Studio, go to AVD Manager, add a virtual device if you haven't done that yet and run the virtual device. Now run flutter run again and it should work.
Note that this way works with any virtual device and not just virtual device from Android Studio.
I solved the problem after changing "ANDROID_HOME" to the Environment variables and setting it to the location of your Android SDK...in my case C:\Android\Sdk.
None of the above solutions worked for me, but I was able to solve it by invalidating catch and restarting my Android Studio:
Menu File → Invalidate Catches / Restart...
EDIT:::
To clear Android Studio’s cache and bring it out of its state of confusion
select ‘File > Invalidate Caches / Restart’ and then click the ‘Invalidate and Restart’ button.
Clean and rebuild your project.
NOTE: I am using a Mi (Xiaomi) mobile (Redmi K20 Pro) which is running on Android 10
You need to do two things to show your device listing.
Go to your Android Studio, menu → File → Project Structure and choose the project SDK from the options. I chose the latest one from the menu.
When you connect your real device to your PC/laptop, make sure you choose Transfer photos (PTP) mode.
NOTE: Don't choose File transfer mode. It will not work.
After doing the above two things, you can check the status of your device availability by writing flutter devices on the command prompt.
I hope it shows your mobile device.
I had the same issue. Setting up the Android SDK is also a correct answer. But this is very simple -
Import an Android project to a new Android Studio window.
Close your current Flutter project Android Studio window.
Import that Flutter project to a new Android Studio window.
It basically needs a device "connected" to your development machine. If you're using a simulator/emulator running on the machine it should automatically be recognised as a connected device. Another way is to connect a physical device and the setup process varies slightly for Android and iOS devices.
This works for me:
Go to Settings > Developer options > Disable USB debugging > Re-enable USB debugging
For Windows users,
The solution for me was running Android Studio as administrator
For me it was
adding "ANDROID_HOME" to the Environment variables and setting it to D:\dev\android\ (for me)
adding "D:\dev\android\platform-tools" (for me) to environment variable PATH. I put flutter there before
OK, OK, OK. Restart Android Studio