How to convert string to Guid [duplicate]

Question

This question already has answers here:

Test if string is a guid without throwing exceptions? (19 answers)

Closed 8 years ago.

I have a string variable which is receiving a Guid. I need to convert this string back to Guid as the database field is of type Guid.

I tried using:

Guid myGuid = Guid.Empty;;
myGuid = Guid.Parse(myId);

But keep getting Format Exception; Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx).

Below is my code:

 public string addVehicleDetails(string vname, string vtype, string regNumber, string ftype, string fefficiency, string insby, DateTime datecreated, string myId)
        {

            string result = string.Empty;
            tblVehicleDetail myVehicleDetails = new tblVehicleDetail();
          //  Guid myGuid = Guid.Empty;
            System.Guid myGuid = new Guid(myId);
           // myGuid = Guid.Parse(myId);
            try {

               // Add details into vehicle details
                myVehicleDetails.VehicleName = vname;
                myVehicleDetails.VehicleType = vtype;
                myVehicleDetails.RegistrationNumber = regNumber;
                myVehicleDetails.FuelType = ftype;
                myVehicleDetails.FuelEfficiency = fefficiency;
                myVehicleDetails.InsuranceBy = insby;

                myVehicleDetails.DateCreated = datecreated;
                myVehicleDetails.Guid = myGuid;

                dc.tblVehicleDetails.InsertOnSubmit(myVehicleDetails);

                dc.SubmitChanges();

                return result = vname;

            }
            catch(Exception exp)
            {
                exp.ToString();
                return result = "Error in Adding Vehicle Details.";
            }
        }

Any solution for this?

Answer 1

This Format Exception tells you that your input(String myId) is not in a recognized format.

You should handle exceptions clearly your input string format is incorrect so use Guid.TryParse(This method returns false if input is null or not in a recognized format, and does not throw an exception.) . Here.

Also check for Guid.TryParseExact method .

  myGuid = Guid.Parse(myId); 
  if (Guid.TryParse(myId, out newGuid))
    {
     try 
      { 
       myVehicleDetails.DateCreated = datecreated; 
       myVehicleDetails.Guid = myGuid; 
       dc.tblVehicleDetails.InsertOnSubmit(myVehicleDetails); 
       dc.SubmitChanges(); 
       } 
     }
     else
      {
        //Input string is not in correct format
      }