如何将字符串转换为Guid

Question

我有一个接收Guid的字符串变量。我需要将此字符串转换回Guid，因为数据库字段的类型为Guid。

我尝试使用：

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

但继续获得Format Exception; Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)。

以下是我的代码：

 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.";
            }
        }

对此有何解决方案？

Answer 1

此Format Exception告诉您输入（String myId）不是可识别的格式。

您应该清楚地处理异常输入字符串格式不正确所以使用Guid.TryParse（如果输入为null或者不是以识别的格式，则此方法返回false，并且不会抛出异常。）。 Here

同时检查Guid.TryParseExact方法。

  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
      }