Re: C# string conversion issues - C# Discussion Boards

29-Nov-09 5:14

Hello! I'm new to C# programming and I have an issue with getting a textbox string to convert to a double.

I'm not sure where I went wrong in the following code, but MS Web Developer isn't liking it:

dEarn = Convert.ToDouble(sEarnings);
dHealth = Convert.ToDouble(txtHealth.Text);
d401k = Convert.ToDouble(txt401k.Text);

I'm trying this two ways: 1) Where "sEarnings" is a string equal to textbox input, and 2) Where I simply try to convert the textbox input directly. Neither way seems to work, and to add clarity, all of this is happening under a Button_Click void.

Thanks!

Dave Kreskowiak29-Nov-09 5:26

Dave Kreskowiak

29-Nov-09 5:26

Have you looked into using Double.TryParse() instead?

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

gtr197129-Nov-09 5:33

29-Nov-09 5:33

Tried dEarn = Double.TryParse(sEarnings);... MS Web Developer complains "No overload for method 'TryParse' takes '1' arguments"

Richard MacCutchan29-Nov-09 5:46

Richard MacCutchan

29-Nov-09 5:46

Try reading the documentation[^].

PIEBALDconsult29-Nov-09 5:50

PIEBALDconsult

29-Nov-09 5:50

Don't use a TextBox for numeric values; use a NumericUpDown.

gtr197129-Nov-09 5:56

29-Nov-09 5:56

This is a project specifically utilizing textbox input. Many tools aren't available to me yet as I am a beginner with C#, though I do have some VB experience. So I don't necessarily know or understand all of the possible ways around an issue.

Basically, think of the most common, elementary way you'd handle this problem and that is likely my answer. Big Grin | :-D

Natza Mitzi
Analysis Studio Statistical Analysis Software

Natza Mitzi29-Nov-09 6:10

Natza Mitzi

29-Nov-09 6:10

Double.TryParse and dont forget formatting and the Culture you are addressing

gtr197129-Nov-09 6:20

29-Nov-09 6:20

Thanks, Natza - but I don't understand what you mean by "culture".

Here's what I'm working with, all under a Button_Click void. I've got an ASP page interacting with this back code. The user enters a number string in a textbox, I want to convert that string into a double and do a calculation. I don't want to test the input here for a boolean yes/no, I want to convert the string a use it.

-------------------
protected void btnCalc_Click(object sender, System.EventArgs e)
{

String sName = (txtName.Text);
String sEarnings = (txtEarnings.Text);
String sHealth = (txtHealth.Text);
String s401k = (txt401k.Text);

dEarn = Convert.ToDouble(sEarnings);
dHealth = Convert.ToDouble(txtHealth.Text);
d401k = Convert.ToDouble(txt401k.Text);

<other code,="" etc....="">

}
--------------------------

Richard MacCutchan29-Nov-09 6:23

Richard MacCutchan

29-Nov-09 6:23

I gave you the answer; see my message above.

Natza Mitzi
Analysis Studio Statistical Analysis Software

Natza Mitzi29-Nov-09 6:32

Natza Mitzi

29-Nov-09 6:32

Hi,
When converting from or to strings (even calling ToString(), you should ALWAYS use the culture in which you intend the formatting for. A general rule of thumb is always use English (us or uk) for internal stuff such as application logs and exporting/importing internal data, this way even when your software or data is moved between computers with different languages it will work. Use the UI culture and number formatting in the UI layer for UI interaction.

Look at this horror:
10.000
An American or english computer will read this as 10$
and a french, german and others will read this as 10000$
Fun fun fun Smile | :)

I think your code should look something like this:

String sEarnings  = txtEarnings.Text;
           double earnings;

           //Use the System.Threading.Thread.CurrentThread.CurrentUICulture.NumberFormat
           //since the text box string data has the UI culture
           bool earningsParseOk = Double.TryParse(
               sEarnings, System.Globalization.NumberStyles.Any,
               System.Threading.Thread.CurrentThread.CurrentUICulture.NumberFormat,
               out earnings);


           //check whether all parsing went ok
           //if not alert
           if (earningsParseOk)
           {
               //go go go
           }
           else
           {
               //error
           }

PIEBALDconsult29-Nov-09 11:39

PIEBALDconsult

29-Nov-09 11:39

gtr1971 wrote:
think of the most common, elementary way you'd handle this problem and that is likely my answer

Mine too -- a NumericUpDown.

Natza Mitzi
Analysis Studio Statistical Analysis Software

Natza Mitzi29-Nov-09 6:34

Natza Mitzi

29-Nov-09 6:34

I replied to someone else by a mistake, please see my coomment, code included

How to creat a Hash Role programmatically

Mehrdad Seyrafi29-Nov-09 0:31

Mehrdad Seyrafi

29-Nov-09 0:31

Hi all
I must define a Hash Rule to control execution of a software from running by a human on a specific station.
I don't have the source code of software and so ... .
What i am doing is that this software must only be exceuted by another software written by me.
So a user may copy the installed files (on another PC) to the specified station and execute it (so bad).
So a Hash Rule is maybe the best method.

What i want is exactly that how to programmatically creating and dropping a "hash rule".

I don't want to manulally set the hash rule.

Note:
In Windows XP pro:
Run -> gpedit.msc -> Computer Configuration/Windows Settings/Security Settings/Software Restriction Policies/Additional Rules/ Right Click on the right panel / New Hash Rule ...

thanks

Re: How to creat a Hash Role programmatically

Dave Kreskowiak29-Nov-09 5:25

Dave Kreskowiak

29-Nov-09 5:25

Your design will not work. When an application is launched, it is launched AS the user that is double-clicking the icon. You cannot prevent users of your application from launching the one your app is supposed to launch. Well, there is one method, but it is so easily defeated and the management/maintenance cost so high, as to not be worth the effort.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

Re: How to create a Hash Role programmatically

Mehrdad Seyrafi29-Nov-09 19:50

Mehrdad Seyrafi

29-Nov-09 19:50

Thanks for reply

Dave, you are right, but i know another way
I think you mean that if an application is prevented from being run by hash code way, it can not be run by another application (mine) as well.

If you mean this, then i have a tricky solution for that, i manipulate the application binary source "exe" file (only a bit toggle is sufficient) so that it works fine, store it in the resource of my application. I extract it only while needed and then will be removed.

I know this way is not perfect, but the users of my application are not professional.

So my only problem is the question in the title of thread.

Re: How to create a Hash Role programmatically

Dave Kreskowiak30-Nov-09 14:46

Dave Kreskowiak

30-Nov-09 14:46

Mehrdad Seyrafi wrote:
If you mean this, then i have a tricky solution for that, i manipulate the application binary source "exe" file (only a bit toggle is sufficient) so that it works fine

There's no need for this at all.

Mehrdad Seyrafi wrote:
store it in the resource of my application. I extract it only while needed and then will be removed.

And there is still nothing from preventing the user from just copying the .EXE to another location and running it from there. If the app also needs to be installed or needs come components to be registered, well... let's just say this is getting more ugly than it already is.

There is simply no good method for doing this.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

Datagridview sorting problem

Yulianto.28-Nov-09 19:43

Yulianto.

28-Nov-09 19:43

Hi, I got a problem with my datagridview sorting. When I use AutoGenerateColumns=true. It can do sorting. But when I set AutoGenerateColumns = false, I can't do the sorting. What am I missing here. Thanks.

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Re: Datagridview sorting problem

Yuri Vital28-Nov-09 23:42

Yuri Vital

28-Nov-09 23:42

Use DatagridView.Sort(Icomparer comparer)
MDSN Documentation here[^]
Wink | ;)

Re: Datagridview sorting problem

Yulianto.29-Nov-09 0:35

Yulianto.

29-Nov-09 0:35

Isn't there any simple solution, because it is working before the AutoGenerateColumns

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Replace a letter in a Textbox?

ahlm28-Nov-09 11:08

ahlm

28-Nov-09 11:08

Hello.

I am creating a program, where i need to have the 29 letter in Textbox1 to be replaced by t

Also xxxxxxxxxxxxxxxxxxxxxxxxxxx(t)xxxxxxxxxxx

Also.. My users, shall paste a link, there is about 30-40 letters, and number 29 shall be changed to a t.

Is that possible?

Regards Ahlmo

Luc Pattyn28-Nov-09 11:12

Luc Pattyn

28-Nov-09 11:12

yes.

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ahlm28-Nov-09 11:13

ahlm

28-Nov-09 11:13

Can you show me Smile | :)

?
Also a tutorials or an example.

Luc Pattyn28-Nov-09 11:28

Luc Pattyn

28-Nov-09 11:28

what you ask for is elementary string manipulation, read up on the String class, and start using some of its methods. If you don't feel comfortable programming in C# (or programming in general), I suggest you start by buying and studying an introductory book.

Smile | :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

ahlm28-Nov-09 11:42

ahlm

28-Nov-09 11:42

I have many books about c#, but can you show me an example for it Smile | :)