Possible Duplicate:
Yield In VB.NET
In C#, when writing a function that returns an IEnumerble<>, you can use yield return to return a single item of the enumeration and yield break; to signify no remaining items. What is the VB.NET syntax for doing the same thing?
An example from the NerdDinner code:
public IEnumerable<RuleViolation> GetRuleViolations() {
if (String.IsNullOrEmpty(Title))
yield return new RuleViolation("Title required","Title");
if (String.IsNullOrEmpty(Description))
yield return new RuleViolation("Description required","Description");
if (String.IsNullOrEmpty(HostedBy))
yield return new RuleViolation("HostedBy required", "HostedBy");
if (String.IsNullOrEmpty(Address))
yield return new RuleViolation("Address required", "Address");
if (String.IsNullOrEmpty(Country))
yield return new RuleViolation("Country required", "Country");
if (String.IsNullOrEmpty(ContactPhone))
yield return new RuleViolation("Phone# required", "ContactPhone");
if (!PhoneValidator.IsValidNumber(ContactPhone, Country))
yield return new RuleViolation("Phone# does not match country", "ContactPhone");
yield break;
}
This convert C# to VB.NET tool gives a “YieldStatement is unsupported” error.
There is currently no equivalent to C#’s yield return in VB.Net from a language syntax level.
However there was a recent write up in MSDN magazine by Bill McCarthy on how to implement a similar pattern in VB.Net 9.0