Type Comparison

[Spencer Wasden]

I want to determine if a control on a form is a TextBox type. I would like
to do something like the following WITHOUT doing a string comparison.

foreach (Control c in this.Controls){
if (c.GetType().ToString() == "System.Windows.Forms.TextBox" ){
MessageBox.Show(c.Text);
}
}


Is this possible?

Thank you

 

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

Spencer,

You can do this:

if (c.GetType() == typeof(System.Windows.Forms.TextBox))

Hope this helps.

 

[Guest]

Hi,

Use the 'is' operator.

Eg:
if( c is TextBox )
{
// do something
}

 

[Mattias Sjögren]

Is this possible?

Sure:

if (c is TextBox)


Mattias

 

[Danny Tuppeny]

Sure:

if (c is TextBox)

Am I right in thinking the different between this, and the method Nicholas
Paldino posted:

if (c.GetType() == typeof(System.Windows.Forms.TextBox))

is that one the first will also return true for things that inherit from
TextBox?

Are there likely to be any performance differences? (If you're doing this
for a large collection of controls, any time saved would be increased!)

 

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

Danny,

My method will check against the textbox class, but will not check for
classes that derive from TextBox (which is the behavior of your original
post).

The one that Mattias and Rakesh posted (using is) will check for classes
that derive from TextBox as well.

 

[Danny Tuppeny]

My method will check against the textbox class, but will not check for
classes that derive from TextBox (which is the behavior of your original
post).

It wasn't my original post, I just butted in because I was curious )

 

[Ollie Riches]

foreach (Control c in this.Controls)
{
if (c.GetType() == typeof(System.Windows.Forms.TextBox )
{
MessageBox.Show(c.Text);
}
}

HTH

Ollie Riches