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How to check for empty GUID

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How to check for empty GUID

Albert Newton

6yAsked Aug 21, 2020, 7:02 AM1.9kLearn iOS Programming

I have in database a empty GUID.

But if I execute this code:

List listOfOneResource = await _resourceService.GetResourcesById(new List { new Guid(welcome.WelcomePopupImage) });
Guid fileId = listOfOneResource.First().FileId ?? Guid.Empty; // this should never be empty in case of an image type resource
string fileIdString = fileId.ToString();
welcome.WelcomePopupImage = _appSettings.MedicalBaseUrl + "/resources/image/" + fileIdString + ".jpg";

I get an error on this line:

List listOfOneResource = await _resourceService.GetResourcesById(new List { new Guid(welcome.WelcomePopupImage) });

"message": "Unrecognized Guid format.",

So what I have to change?

4 Replies

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Jignesh Kumar6y ago
Hi,

Please use this link,
https://ozanecare.com/how-to-check-guid-is-null-or-empty/
Navaneeth Krishnan6y ago
Try Guid.Empty

https://docs.microsoft.com/en-us/dotnet/api/system.guid.empty?view=netcore-3.1
Varun Setia6y ago
1. Guid output;
2. if(Guid.TryParse(input,out output))
3. {
4. //Logic
5. }

Laxmidhar Sahoo

Laxmidhar Sahoo6y ago

hi

You define the List in the wrong way

var guid = new Guid(welcome.WelcomePopupImage);
if(guid != null)
{
List guids = new List();
var listOfOneResource = await _resourceService.GetResourcesById(guids);
}

Thanks and regards