Problem checking for double 2

[DotNetBlocks]

Hello All,
I am having a problem. I have a textbox with a value that is a double "12.90", how can i check to make sure the type is double. I want to send a message if it is not.

Thanks,
babloome

 

[ThatRickGuy]

I'm not sure if there is an IsDecimal funtion, but this should attempt to cast the string to decimal:

try
  dim dTest as decimal = cdec(textbox1.text)
catch 
  messagebox.show("Please enter a decimal in text box 1.")
end try

-Rick

VB.Net Forum forum796 forum855 ASP.NET Forum
I believe in killer coding ninja monkeys.

 

[jo0ls]

Here's a vb 2005 only tip:

        Dim iVal As Double
        If Double.TryParse(TextBox1.Text, iVal) Then
            Me.Text = iVal.ToString
        Else
            Me.Text = "Enter a double you fool!!"
        End If

This is recommended as using try..catch is slow when the catch block is hit. See:

http://msdn.microsoft.com/msdnmag/issues/06/01/CLRInsideOut/

 

[ThatRickGuy]

FYI, TryParse is in .Net 1.0/1.1 also. I completely forgot about it! joOls' code is as he said, more efficient, and much prettier

-Rick

VB.Net Forum forum796 forum855 ASP.NET Forum
I believe in killer coding ninja monkeys.

 

[chrissie1]

Yes but I wouldn't do the me.text = "Enter a double you fool!!" since this could get you into an endless loop because the textbox will only accept doubles. And most user would just try entering "a double you fool!!" wich would give you even more work.


Christiaan Baes
Belgium

"My new site" - Me

 

[DotNetBlocks]

Thanks for the help everyone, I will try the example now.

Babloome