C# / VB.Net issue: VB.Net fills string array but C# doesn't

Question

I'm working with referenced VB6 DLL's. The problem is that the results of a method/function call are not the same. Below the code examples:

First VB.Net

Dim Validations() As String
myErr = myEntry.ValidateLine(Validations)

When validation fails, the string array Validations is filled with the error description string. I've tried to accomplish the same in C#:

private string[] valArray = null;
sdkError = sdkEntry.ValidateLine(valArray);

Does anyone have an idea why I can't get C# to fill the string array?

Additionally, the function in VB is called with ref to a System.Array ...

ValidateLine(ref System.Array ValErrors), perhaps it has something to do with this?

Jon Skeet · Accepted Answer · 2012-02-04 10:23:09Z

2

My guess is that VB is implicitly passing your variable by reference. You could try doing the same thing in C#:

sdkError = sdkEntry.ValidateLine(ref valArray);

(It's not immediately clear how you're invoking the VB DLL, mind you.)

answered Feb 4, 2012 at 10:23

Jon Skeet

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Comments

ilivewithian · Accepted Answer · 2012-02-04 10:22:43Z

0

Your VB creates and empty array, your C# creates a null array. I'm guessing the VB dll needs a non null value.

Try swapping your C# to this:

private string[] valArray = new string[]{};

answered Feb 4, 2012 at 10:22

ilivewithian

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The DLL still isn't going to be able to populate that array. (Also, = new string[0] would be simpler, or just = {};.)

The VB is also creating a null array reference, identical to the C#