CODEWITHSUNDEEP
javascriptbluetoothuwpwinjs
Priyank C
Priyank C

Reputation: 1

UWP Bluetooth: issues with DeviceWatcher and findAllAsync()

I wanted to get Bluetooth devices using UWP. I really want to use Devicewatcher as I should be continued looking for new devices.

The result I get in Added event of the DeviceWatcher is DeviceInformation and does not have all the properties I need in my app, hence I should be calling something to get the BluetoothDevice object. The problem is when I call the following methods with the Device.ID that I got from DeviceWatcher have different errors:

As I read in another post, I also tried getting the devices from DeviceInformation.findAllAsync() all calling both the above methods but same result. (winjs-and-bluetooth-connection-error)

Can Anyone suggest what the issue is or another approach? My Codes are as below.

Code to create watcher:

ondeviceadd = function (args) {
    //my code here
};
deviceWatch = Windows.Devices.Enumeration.DeviceInformation.createWatcher(selector, null);
deviceWatch.addEventListener("added", ondeviceadd);
deviceWatch.addEventListener("removed", ondeviceRemove);
deviceWatch.addEventListener("updated", ondeviceUpdate);
deviceWatch.addEventListener("stopped", onStopped);
deviceWatch.addEventListener("enumerationcompleted", ondeviceComplete);
deviceWatch.start();

Code to get device from findAllAsync:

var selector = Windows.Devices.Bluetooth.BluetoothDevice.getDeviceSelector();
Windows.Devices.Enumeration.DeviceInformation.findAllAsync(selector, null).done(function (data) {
    for (var i = 0; i < data.length; i++) {
        //My code here
    }
});

Code to get BluetoothDevice:

Windows.Devices.Bluetooth.BluetoothDevice.fromBluetoothAddressAsync(devid).done(
function(devinfo) {
    res = devinfo;
})
Windows.Devices.Bluetooth.BluetoothDevice.fromIdAsync(data.id).done(function(result){
    //my code here
});
Windows.Devices.Bluetooth.Rfcomm.RfcommDeviceService.fromIdAsync(devId).done(function (result) {    
    //my code here
})

Upvotes: 0

Views: 1279

Answers (1)

Jay Zuo
Jay Zuo

Reputation: 15758

BluetoothDevice.FromIdAsync | fromIdAsync method is the right method to get the BluetoothDevice object with the given Device Id. And in DeviceWatcher.Added | added event, we can get the DeviceInformation object which contains DeviceInformation.Id | id property but no Bluetooth Address info. So BluetoothDevice.FromBluetoothAddressAsync | fromBluetoothAddressAsync method can't be used here.

However while using BluetoothDevice.fromIdAsync method, we need note that this method needs bluetooth capability. See Requirements → Capabilities and also Device capabilities. So to use this method, we need add Bluetooth Capability in Package.appxmanifest like:enter image description here

And then when we first call this method, the system will request user to give permission to access the Bluetooth device. If the user chooses Yes, this method will return a BluetoothDevice object represents the device. But if the use chooses No then this method will return null.

Upvotes: 0

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