Question

Here I have:

Public Structure MyStruct    Public Name as String    Public Content as String End Structure  Dim oStruct as MyStruct = New MyStruct() oStruct.Name = ... oStruct.Content = ...  Dim alList as ArrayList = new ArrayList() alList.Add(oStruct) 

I’d like to convert the ArrayList to a static strongly-typed Array of type MyStruct. How can I do that? I had no luck with ToArray.

I am using .NET Framework 2.0.

Answer 1

I assume that since you are using ArrayList, you are using 1.1?

In which case, I suspect the following would work:

ArrayList list = new ArrayList(); MyStruct[] array = new MyStruct[list.Count]; list.CopyTo(array);  

(edit – Bill’s ToArray usage is more convenient – I didn’t know about that one, but then, I very rarely [if ever] use ArrayList)

However, if MyStruct really is a struct, then I cannot say strongly enough that mutable structs are a bad idea – i.e. where you can set .Name and .Content after creation. Structs should almost always be immutable. In reality, your MyStruct looks like it should be a class. Also – I’m not ‘up’ on VB, but are they public fields? Again – not recommended – properties would be preferable. I don’t know about VB, but C# 3.0 has some very terse syntax for this:

public class SomeType {     public string Name {get;set;}     public string Content {get;set;} } 

If you are using 2.0 or above, consider List<T> instead of ArrayList.