BleManager not work on Android Api Level 31

Question

I have a app which scans the bluetooth devices. It was working well until android says api level must be 31 or higher.

So i change my code like below:

buildscript {
    ext {
        buildToolsVersion = "29.0.3"
        minSdkVersion = 21
        compileSdkVersion = 31 // edit (30->31)
        targetSdkVersion = 31 // edit (30->31)
        googlePlayServicesAuthVersion = "16.0.1"
    }
    repositories {
        google()
        mavenCentral()
        jcenter()
    }
    dependencies {
        classpath("com.android.tools.build:gradle:4.1.0")
        classpath 'com.google.gms:google-services:4.3.10'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

and :

allprojects {
    repositories {
        //*************************** edit part ***************************
        exclusiveContent {
           filter {
               includeGroup "com.facebook.react"
           }
           forRepository {
               maven {
                   url "$rootDir/../node_modules/react-native/android"
               }
           }
        }
        //*************************** edit part ***************************
        mavenLocal()
        maven {
            // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm
            url("$rootDir/../node_modules/react-native/android")
        }
        maven {
            // Android JSC is installed from npm
            url("$rootDir/../node_modules/jsc-android/dist")
        }

        google()
        jcenter()
        maven { url 'https://www.jitpack.io' }
    }
}

After i change my code like above, bleManager stop working. It says "cannot start scanning operation". I also print the manager object. Here it is :

{"_activePromises": {}, "_activeSubscriptions": {}, "_errorCodesToMessagesMapping": {"0": "Unknown error occurred. This is probably a bug! Check reason property.", "1": "BleManager was destroyed", "100": "BluetoothLE is unsupported on this device", "101": "Device is not authorized to use BluetoothLE", "102": "BluetoothLE is powered off", "103": "BluetoothLE is in unknown state", "104": "BluetoothLE is resetting", "105": "Bluetooth state change failed", "2": "Operation was cancelled", "200": "Device {deviceID} connection failed", "201": "Device {deviceID} was disconnected", "202": "RSSI read failed for device {deviceID}", "203": "Device {deviceID} is already connected", "204": "Device {deviceID} not found", "205": "Device {deviceID} is not connected", "206": "Device {deviceID} could not change MTU size", "3": "Operation timed out", "300": "Services discovery failed for device {deviceID}", "301": "Included services discovery failed for device {deviceID} and service: {serviceUUID}", "302": "Service {serviceUUID} for device {deviceID} not found", "303": "Services not discovered for device {deviceID}", "4": "Operation was rejected", "400": "Characteristic discovery failed for device {deviceID} and service {serviceUUID}", "401": "Characteristic {characteristicUUID} write failed for device {deviceID} and service {serviceUUID}", "402": "Characteristic {characteristicUUID} read failed for device {deviceID} and service {serviceUUID}", "403": "Characteristic {characteristicUUID} notify change failed for device {deviceID} and service {serviceUUID}", "404": "Characteristic {characteristicUUID} not found", "405": "Characteristics not discovered for device {deviceID} and service {serviceUUID}", "406": "Cannot write to characteristic {characteristicUUID} with invalid data format: {internalMessage}", "5": "Invalid UUIDs or IDs were passed: {internalMessage}", "500": "Descriptor {descriptorUUID} discovery failed for device {deviceID}, service {serviceUUID} and characteristic {characteristicUUID}", "501": "Descriptor {descriptorUUID} write failed for device {deviceID}, service {serviceUUID} and characteristic {characteristicUUID}", "502": "Descriptor {descriptorUUID} read failed for device {deviceID}, service {serviceUUID} and characteristic {characteristicUUID}", "503": "Descriptor {descriptorUUID} not found", "504": "Descriptors not discovered for device {deviceID}, service {serviceUUID} and characteristic {characteristicUUID}", "505": "Cannot write to descriptor {descriptorUUID} with invalid data format: {internalMessage}", "506": "Cannot write to descriptor {descriptorUUID}. It's not allowed by iOS and therefore forbidden on Android as well.", "600": "Cannot start scanning operation", "601": "Location services are disabled"}, "_eventEmitter": {"_disableCallsIntoModule": false, "_subscriber": {"_currentSubscription": null, "_subscriptionsForType": [Object]}}, "_scanEventSubscription": {"context": undefined, "emitter": {"_disableCallsIntoModule": false, "_subscriber": [EventSubscriptionVendor]}, "eventType": "ScanEvent", "key": 1, "listener": [Function scanListener], "subscriber": {"_currentSubscription": null, "_subscriptionsForType": [Object]}}, "_uniqueId": 2}

Can anyone help me ?

I explain that part in the detail part

Answer 1

You need to change the Bluetooth permissions of your app.

For example, if you want to scan for devices you need the BLUETOOTH_SCAN permission. You should note that this is a runtime permission.