Translate C# Ctor to Vb.Net equivalent

Question

I have taken this struct definition from the Windows API CodePack:

public struct IconReference
{
    //...

    public IconReference(string moduleName, int resourceId)
        : this()
    {
        //...
    }

    public IconReference(string refPath)
        : this()
    {
        //...
    }

    //...
}

The problem is I don't understand how to translate those kind of constructors to Vb.Net.

What is exactlly the meaning of that : this()?

When I use an online code translator, it translates it as Me.New(), however, this fails at compilation because that struct does not have a parameterless ctor.

There is no purpose to it, a struct cannot have a default constructor. Just omit. — Hans Passant, Feb 12 '16 at 08:48

Patrick Hofman · Accepted Answer · 2016-02-12T08:54:49.687

3

The this() in C# calls the parameterless constructor. Since you don't have a parameterless constructor in C# (and structs can't even contain "explicit parameterless constructors"), you can omit the this().

And so for the VB.NET code. You can omit the Me.New() code.

edited Feb 12 '16 at 08:54

answered Feb 12 '16 at 08:49

Patrick Hofman

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Yes a default constructor can be specified in Vb.Net but the MSDN guidelines says it is incorrect to do it, I'm not sure why the WindowsAPICodePack guys did that, but if I can omit it then problem solved, thanks. – ElektroStudios Feb 12 '16 at 08:56
1

You are welcome. VB.NET gave me an error in VS2015, but not in Ideone, so I think they use an outdated compiler. Probably this has been 'fixed' in the lastest version of the VB.NET compiler. – Patrick Hofman Feb 12 '16 at 08:57
If you omit the call to the default constructor in C#, you'll hit a [compiler error](https://msdn.microsoft.com/en-us/library/bb513821.aspx), since the class has a automatically implemented property. – sloth Feb 12 '16 at 09:54
Indeed, not the code OP gave, but as Hans pointed out, that code is incomplete... @sloth – Patrick Hofman Feb 12 '16 at 09:55

score 2 · Answer 2 · edited May 23 '17 at 12:31

2

This syntax is needed because IconReference has an "automatically implemented property":

  public int ResourceId { get; set; }

see also https://stackoverflow.com/a/7670854/121309

edited May 23 '17 at 12:31

Community

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1

answered Feb 12 '16 at 09:20

Hans Keﬆing

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Translate C# Ctor to Vb.Net equivalent

2 Answers2