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[react-native]could not connect to development server on android

When I run "react-native run-android",it gives me error:"could not connect to development server...".

So how to fix the red error screen issue?Any suggestion is appreciated!

enter image description here

adb reverse

7 Answers
7

From the Docs:
http://facebook.github.io/react-native/docs/running-on-device.html#method-2-connect-via-wi-fi

Method 2: Connect via Wi-Fi

You can also connect to the development server over Wi-Fi. You'll

first need to install the app on your device using a USB cable, but

once that has been done you can debug wirelessly by following these

instructions. You'll need your development machine's current IP

address before proceeding.

Open a terminal and type /sbin/ifconfig to find your machine's IP
address.

react-native init myProject

adb shell input keyevent 82

f you are trying to debug app in your physical android device over wifi using a windows machine, then the device may not be able to access the port of your pc or laptop,
you have to make the port accessible. this involves two steps:

1.First create a rule in firewall. for doing this follow the following steps:

open run dialog
-type wf.msc
-click on inbound rules
-click new rule on right hand side
-select port from pop up menu and click next
-select tcp port and specific local ports and enter the port number like 8081(default)
-allow the connection
-select all in profile section
-give some appropriate name and description
-click finish

You are good to go, now try running react-native run-android.

This is most probably a firewall issue. If someone using ubuntu faces this issue , then you can use

sudo service iptables stop


to disable the firewall for the port to be accessible

and first of all I appreciate you for posting your doubt.
It's mainly because maybe your expo or the app in which you run your react native project may not be in the same local connected wifi or LAN.
Also, there is a chance that there is disturbance in your connection frequently due to which it loses its connectivity.

I too face this problem and I personally clear the cache and then restart again and boom it restarts perfectly.
I hope this works for you too!

To add to goldylucks's answer, you can use IP 192.168.0.10 if that is the IP of your PC running the React Native packager.

goldylucks

You may need to open your firewall as well.

In Ubuntu 18.04, you can get your IP by:

ip -c addr show


You will see your IP in there, something like: inet 192.168.0.10/24 brd 192.168.0.255 scope global dynamic noprefixroute enp0s25 (notice the 192.168.0.10 in my sample).

inet 192.168.0.10/24 brd 192.168.0.255 scope global dynamic noprefixroute enp0s25

Then, you could open port 8081 in your firewall, something like:

sudo ufw allow 8081


It will be using TCP, so make sure TCP is open on port 8081.

Then you can follow goldylucks's answer and goto Dev settings and enter 192.168.0.10:8081 or whatever IP you need.

Dev settings

192.168.0.10:8081

You can test it from the browser on your device. While the packager is running from your PC, navigate to http://192.168.0.10:8081 from your mobile device and make sure it works. It will show something like "Packager running". It will be clearly working or failing.

http://192.168.0.10:8081

Goldylock's answer excites me because it solves the issue very nicely if you are having problems with that error messages. It sucks to have to rebuild the app all the time or worse yet, delete the APK off your device and then build again.

As such, you should probably be using wifi as part of your dev strategy.

We faced this issue, In order to fix this, solution is dead simple is below.

Basically this error tells that your current build got failed due to reasons like Code issue or dependency issue.

Click here for more details

Basically this error tells that your current build got failed due to reasons like Code issue or dependency issue.

In order to fix this issue, solution is dead simple is below.

react-native run-android

react-native run-android

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