errors.md

Handling errors in the Microsoft Graph .NET Client Library

Errors in the Microsoft Graph .NET Client Library behave like errors returned from the Microsoft Graph service. You can read more about them here.

Anytime you make a request against the service there is the potential for an error. In the case of an error, the request will throw a ODataError exception that contains the service error details and can be handled as below.

try
{
    await graphServiceClient.Me.PatchAsync(user);
}
catch (ODataError odataError)
{
    Console.WriteLine(odataError.Error?.Code);
    Console.WriteLine(odataError.Error?.Message);
    throw;
}

Checking the error status code

You can check the status code that caused the error as below.

catch (ODataError odataError) when (odataError.ResponseStatusCode == (int)HttpStatusCode.NotFound)
{
        // Handle 404 status code
}

Checking the error

There are a few different types of errors that can occur during a network call. These most common error codes are defined in GraphErrorCode.cs. These can be checked by matching with the error code value as below.

catch (ODataError odataError) when (odataError.Error.Code.Equals(GraphErrorCode.AccessDenied.ToString()))
{
        // Handle access denied error
}

Each error object has a Message property as well as code. This message is for debugging purposes and is not be meant to be displayed to the user. Common error codes are defined in GraphErrorCode.cs.