DeviceTwin issue in updating properties

Question

I have a problem updating a property attribute with DeviceTwin in c #.

The code I execute is the following:

            var registryManager = RegistryManager.CreateFromConnectionString(AppSettings.KeyIoT);
            var twin = await registryManager.GetTwinAsync(dto.DeviceIdorId);

            TwinCollection s = twin.Properties.Reported["Power"];

            Power toRet = JsonConvert.DeserializeObject<Power>(s.ToJson());
            toRet.MaximumAvailable = 50;

           var patch =
            @"{
            properties: {
                reported:{
                  Power:" + JsonConvert.SerializeObject(toRet) +
                @"}
                }
            }";

            await registryManager.UpdateTwinAsync(twin.DeviceId, patch, twin.ETag);

I tried also with the following code :

            var registryManager = RegistryManager.CreateFromConnectionString(AppSettings.KeyIoT);
            var twin = await registryManager.GetTwinAsync(dto.DeviceIdorId);

            TwinCollection s = twin.Properties.Reported["Power"];

            Power toRet = JsonConvert.DeserializeObject<Power>(s.ToJson());
            toRet.MaximumAvailable = 50;

            twin.Properties.Reported["Power"] = JsonConvert.SerializeObject(toRet);

            Twin updatedTwin = await registryManager.UpdateTwinAsync(twin.DeviceId, twin, twin.ETag);

The problem is that after the update, if I do a reread, the property MaximumAvailable is not updated. What am I doing wrong? Thanks.

Is this related? https://stackoverflow.com/questions/51768883/updatetwinasync-failing — Ian Mercer, Nov 27 '19 at 01:40

score 1 · Accepted Answer · answered Nov 27 '19 at 07:03

1

The device twin reported properties are readonly on the service-facing side. See more details here

answered Nov 27 '19 at 07:03

Roman Kiss

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If I change reported with desidered I get the following error : **"Additional text found in JSON string after finishing deserializing object. Path 'properties.desidered', line 4, position 112."}"** What am I doing wrong? Thanks. – Simone Spagna Nov 27 '19 at 10:57
1

your code with a patch implementation (the first one) is working well. Did you change a *reported* to the *desired* in the patch json formatted text, too? – Roman Kiss Nov 27 '19 at 12:02
Yes, I changed a reported to the desidered in the patch Json formatted text and I got the error. – Simone Spagna Nov 27 '19 at 12:54

DeviceTwin issue in updating properties

1 Answers1