convert string to ref System.Array

[Janus Knudsen]

Hello

Im getting an error when I try to convert like this:
string[] arrDSN;

objDSN.GetDataSourceList(arrDSN)

And the error: Argument '1': cannot convert from 'string[]' to 'ref
System.Array'

Kind regards

 

[Bjorn Abelli]

...

Im getting an error when I try to convert like this:
string[] arrDSN;

objDSN.GetDataSourceList(arrDSN)

And the error: Argument '1': cannot
convert from 'string[]' to 'ref
System.Array'

Two things to do.

Cast the string array to a System.Array:

Array sa = (Array) arrDSN;

The error message tells us that the method expects a "reference":

objDSN.GetDataSourceList(ref sa)

// Bjorn A

 

[Brad Williams]

A ref param must be an lvalue variable of exactly the expected type, eg it
can't be a variable of a derived class. In your case, if you created a new
variable of type System.Array you could pass a ref to that.

Brad Williams

 

[Janus Knudsen]

Thank you very much!

However if I dont assign the arrDSN like this:
string[] arrDSN = new string[10];

I also get an error, is there any way to avoid this? - Maybe have the array
to autoexpand or to use it unassigned... It cannot be castet to an array:
Array sa = (Array)arrDSN; - when it's unassigned apparently?


Kind regards
Janus

...

Im getting an error when I try to convert like this:
string[] arrDSN;

objDSN.GetDataSourceList(arrDSN)

And the error: Argument '1': cannot
convert from 'string[]' to 'ref
System.Array'

Two things to do.

Cast the string array to a System.Array:

Array sa = (Array) arrDSN;

The error message tells us that the method expects a "reference":

objDSN.GetDataSourceList(ref sa)

// Bjorn A

 

[Bjorn Abelli]

...

However if I dont assign the arrDSN like this:
string[] arrDSN = new string[10];

I also get an error, is there any way to avoid this?

No, not completely, as you can't "use" an unassigned variable.

But as the GetDataSourceList suggests that it actually is going to *change*
the reference to your array anyway as it's using the ref keyword, I believe
you can use an "empty" array.

string[] arrDSN = new string[0];


// Bjorn A