Flutter 热重载在我的设备上不起作用

Question

On my device, flutter does not hot reload, I initially thought this was a problem with flutter or android studio or vs code but when I use a different device, the hot reload is working. How do I resolve this, it's just been driving me crazy and I have already spent a lot of hours trying to figure this out.

And btw, it was initially working on this device until it wasn't, and I have already restarted my phone, I have even reinstalled flutter, basically every suggestion from the internet I have tried but so far, no fruits.

Any help would be highly appreciated, here is the flutter doctor -v.

[✓] Flutter (Channel stable, v1.12.13+hotfix.9, on Linux, locale en_US.UTF-8)
• Flutter version 1.12.13+hotfix.9 at /home/hamisi/flutter
• Framework revision f139b11009 (5 weeks ago), 2020-03-30 13:57:30 -0700
• Engine revision af51afceb8
• Dart version 2.7.2


[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /home/hamisi/android
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-29, build-tools 29.0.2
    • ANDROID_HOME = /home/hamisi/android/
    • Java binary at: /home/hamisi/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
    • All Android licenses accepted.

[✓] Android Studio (version 3.5)
    • Android Studio at /home/hamisi/android-studio
    • Flutter plugin version 44.0.1
    • Dart plugin version 191.8593
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)

[✓] Connected device (1 available)
    • LG H845 • LGH845e35cd375 • android-arm • Android 7.0 (API 24)

• No issues found!

The output from flutter run -v --trace-startup is https://pastebin.com/9X4S5LWr

Answer 1

I had this exact problem with a Pixel 2. Fine one minute, then boom - hot reload / restart was not available. I could deploy the app to the device, but hot reload options were greyed out in Android Studio and hot reload keyboard shortcuts did nothing. Pressing r after flutter run also did nothing. Nothing significant happened in between it working and it not working - no updates to Android Studio, Flutter or the device. I tried restarting the device, Android Studio, flutter clean , I tried swapping the USB cable, nothing seemed to work.

It did eventually start working again: I did a flutter clean followed immediately by a reboot of my computer. I have no idea if this was the fix, or whether it was just one of those random who-the-f-knows, but hopefully it will help anyone else.

[√] Flutter (Channel stable, v1.17.0, on Microsoft Windows [Version 10.0.18362.778], locale en-GB)
    • Flutter version 1.17.0 at D:\flutter
    • Framework revision e6b34c2b5c (10 days ago), 2020-05-02 11:39:18 -0700
    • Engine revision 540786dd51
    • Dart version 2.8.1


[√] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
    • Android SDK at C:\Users\james\AppData\Local\Android\sdk
    • Platform android-29, build-tools 29.0.3
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)
    • All Android licenses accepted.

[√] Android Studio (version 3.6)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 45.1.1
    • Dart plugin version 192.7761
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b04)

[√] Connected device (1 available)
    • Pixel 2 • HT7C11A06689 • android-arm64 • Android 10 (API 29)

• No issues found!

Answer 2

I had this issue some days ago I did a couple of things:

1. In some files may be added file:/// before the file name in the above file. Search in the whole project and remove file:/// line and again import that package again.

2. flutter upgrade

3. Clean project( flutter clean )

4. I also change my emulator .

that worked for me

Answer 3

if you are using an android virtual device. navigate to its settings => proxy then untick 'Use android studio http proxy settings' select 'No proxy'... that worked for me.

Answer 4

For anyone else who runs into this issue and has installed VS Code Hotkeys/Keymap for Android Studio, the default VS Code hotkey for "Save All" will immediately stop hot reload from working. (With VS Code hotkeys this is Ctrl+K or S)

Simply removing the "Ctrl+K, S" and replacing it with Ctrl+S worked after days of trying to fix this. Screenshot below. File -> Settings -> Keymap -> Search for "save"

Screenshot with Instructions (Settings -> Keymap)

Answer 5

HotReload was not working me as well, but I searched for it and found the solution.

When you click on the HotReload it will work only in the changes inside the Build() Widget, if your code is outside the build() widget then it will not work...

Thanks

Answer 6

I had the same problem, All you need to do: 1. wipe data in the android emulator 2.cold boot the device and done.

Answer 7

Since you have all necessary plugin installed and your flutter-doctor has no issues.

Try running the command flutter clean . Hopefully that is going to work.

I hope this helps.

Answer 8

If you are still not able to figure it out check this method.

When you import widget from another.dart file. sometime android studio will import this path.

import file:///C:/kharag/.../.../< App Name >/lib/filename.dart

Hot reload and hot restart will not work in that case. To fix that you should find and remove file path and replace with given path format below

import package:< App Name >/filename.dart

Note: To see the change stop your app and run again