Casting in C#

[David P. Donahue]

What is the C# equivelant of the following VB:

CType(controlTemplate, TextBox).Text = ""

I'm basically trying to use a more general object as an argument in one
of my functions and then change the behavior within the function based
on its type.



Regards,
David P. Donahue
(e-mail address removed)

 

[Nicholas Paldino [.NET/C# MVP]]

David,

You would do this:

// Cast to a textbox and set the text property.
((TextBox) controlTemplate).Text = string.Empty;

Hope this helps.

 

[Richard Blewett [DevelopMentor]]

The equivelent is the cast operator

((TextBox)controlTemplate).Text = "";

Regards

Richard Blewett - DevelopMentor
http://staff.develop.com/richardb/weblog

What is the C# equivelant of the following VB:

CType(controlTemplate, TextBox).Text = ""

I'm basically trying to use a more general object as an argument in one
of my functions and then change the behavior within the function based
on its type.

 

[Guest]

Hi David,

Use:
((TextBox)controlTemplate).Text = ""

HTH,
Rakesh Rajan

 

[David Anton]

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[James Curran]

In addition to the short form given by the others, this method is a bit
safer:

TextBox tb = controlTemplate as TextBox;
if (tb != null)
tb.Text = "";

--
Truth,
James Curran
Home: www.noveltheory.com Work: www.njtheater.com
Blog: www.honestillusion.com Day Job: www.partsearch.com
(note new day job!)

 

[The Last Gunslinger]

In addition to the short form given by the others, this method is a bit
safer:

TextBox tb = controlTemplate as TextBox;
if (tb != null)
tb.Text = "";

I agree,
Casting using "As" will return null if cast fails instead of an
invalidcastexception.

HTH
JB

 

[Jon Skeet [C# MVP]]

I agree,
Casting using "As" will return null if cast fails instead of an
invalidcastexception.

Why is that good though? If I've got something which *should* be a
TextBox, why is it good to mask the fact that my assumption is wrong?

There are times when it's better to use "as" - namely if your code
really doesn't know whether the cast should work or not - and there are
times when it's better to use a cast.