• 0

C# Calculating textbox values?


Question

Hi,

I have an application with 20 textboxes, i need to do the calculations for example ((TextBox12 * TextBox1 * TextBox7) / 2) and display the result on label when clicking a button.

Ive usually done these like this:


private void lBtn_Click(object sender, EventArgs e)
{
double L, L2;
if (double.TryParse(kTb1.Text, out L) && double.TryParse(kTb2.Text, out L2))
lBl4.Text = String.Format("{0:f1}", (L2 * L));
else
MessageBox.Show("WTF
}
[/CODE]

I was wondering if there is better way to do this so that I don't have to add all 20 textboxes into this with && double.TryParse?

Link to comment
https://www.neowin.net/forum/topic/1083591-c-calculating-textbox-values/
Share on other sites

17 answers to this question

Recommended Posts

  • 0

You could add the text boxes into an array, and then iterate over the array...


private void lBtn_Click(object sender, EventArgs e) {
TextBox[] textboxes = {
kTb1,
kTb2,
kTb3,
...
kTb20
};

double temp = 0D, total = 0D;
bool isError = false;
foreach (TextBox tb in textboxes)
{
if (!double.TryParse(tb.Text, out temp))
{
isError = true;
break;
}

total *= temp
}

if (isError)
MessageBox.Show("WTF
else
lBl4.Text = String.Format("{0:f1}", total);
}
[/CODE]

To generate the array, you could create it in the form's constructor (or OnLoad event handler), and store it as a class variable...

[CODE]
TextBox[] m_textboxes;

protected void Form1_Load(Object sender, EventArgs e)
{
TextBox[] m_textboxes = {
kTb1,
kTb2,
kTb3,
...
kTb20
};
}
[/CODE]

If the only text boxes on the form are the ones you'll be using in the calculation, you could also use the Controls property to get the list of child text boxes :)

  • 0
  On 12/06/2012 at 12:26, mute~ said:

I'd put the textboxes into a panel, iterate the panels controls where the type is a textbox, load the value into an object then use the object to output your requirements.

Agreed that this is the best way to go.

  • 0

An application with 20 textboxes sounds like a pain in the ass to begin with. That said, you can at least factor out repetitive code inside methods, for instance you could create an extension method for textboxes to get their value as a double:


public static double getValue(this TextBox txtBox) {
return double.Parse(txtBox.Text;)
}
[/CODE]

So your code can look like:

[CODE]
try {
lbl4.Text = string.Format("{0:f0}", txt1.getValue() * txt2.getValue() / 3);
}
catch (Exception) {
MessageBox.Show("WTF
}
[/CODE]

Btw double.Parse with a try-catch (rather than TryParse) is probably the best approach here, it's not like the cost of throwing an exception in this case was of any significance and it leads to cleaner code.

  • 0
  On 12/06/2012 at 15:47, Dr_Asik said:

An application with 20 textboxes sound like a pain in the ass to begin with. That said, you can at least factor out repetitive code inside methods, for instance you could create an extension method for textboxes to get their value as a double:


<snip>
[/CODE]

Btw double.Parse with a try-catch (rather than TryParse) is probably the best approach here, it's not like the cost of throwing an exception in this case was of any significance and it leads to cleaner code.

How does what you did eliminate repetitive code versus simply using a loop? Using an extension method seems a bit overkill.

  • 0
  On 12/06/2012 at 15:55, Majesticmerc said:

How does what you did eliminate repetitive code versus simply using a loop? Using an extension method seems a bit overkill.

Assuming he's doing some operation that involves getting the values of all textboxes indistinctly (like a sum or an average), a loop is the obvious solution, but from his code example I gathered he wants to do operations involving specific textboxes and is wondering how to avoid having to write the double.TryParse boilerplate every time. Maybe I just misinterpreted though, anyway the loop solution was already given by others here.
  • 0
  On 12/06/2012 at 15:59, Dr_Asik said:

Assuming he's doing some operation that involves getting the values of all textboxes indistinctly (like a sum or an average), a loop is the obvious solution, but from his code example I gathered he wants to do operations involving specific textboxes and is wondering how to avoid having to write the double.TryParse boilerplate every time. Maybe I just misinterpreted though, anyway the loop solution was already given by others here.

Actually yeah I see your point now; the first code snippet in the OP seems to suggest arbitrary calculations while the later code snippets suggest otherwise. Interesting.

  • 0

I wonder if the textboxes are the right way to do this afterall?

This application will have 50 textboxes and user inputs values 1-5. Two buttons, calculate and clear. After the calculations it shows a the results of 8 calculations and also a graph.

I first thought I do it with popup dialog but then decided to use textboxes so that user can check the entered values but it will have alot of textboxes...

Any ideas?

  • 0
  On 14/06/2012 at 07:31, Joni_78 said:
I wonder if the textboxes are the right way to do this afterall? This application will have 50 textboxes and user inputs values 1-5. Two buttons, calculate and clear. After the calculations it shows a the results of 8 calculations and also a graph. I first thought I do it with popup dialog but then decided to use textboxes so that user can check the entered values but it will have alot of textboxes... Any ideas?
So the user has 5 values to enter and you want to display the result of 8 calculations. Why do you need 50 different fields for that?

I'm not too familiar with Winforms but if you have a lot of data it's usually better to display it with some kind of list control, perhaps DataGrid or ListView.

  • 0
  On 14/06/2012 at 13:38, Dr_Asik said:

So the user has 5 values to enter and you want to display the result of 8 calculations. Why do you need 50 different fields for that?

I'm not too familiar with Winforms but if you have a lot of data it's usually better to display it with some kind of list control, perhaps DataGrid or ListView.

I meant user needs to enter value 1-5 for every textbox.

  • 0

Ok so you have 8 different calculations that all require 5 inputs for the user and a field to display the result, if I understand correctly. So you could design a UserControl that has 5 input fields and a result field, and use that 8 times with a different equation passed in as a parameter. The equation could be a five-argument Func where the arguments are the 5 different textbox values. Does that make any sense for you?

  • Like 1
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • Hello, Hardware Support Applications are a special kind of Microsoft Store app and have to go through additional checks and certifications because they can communicate directly with their driver, which means that a vulnerability in one of them could allow an attacker access to kernel space memory through the HSA ←→ device driver interface.  In other words, a BYOVD (bring your won vulnerable driver) attack, but with the HSA being used as an extra step. Remember, the Microsoft Store is strategic to Microsoft's long-term goals: they see it as the means to get the same 30% of every application sale that Apple and Google get through their stores, which is why it has been a fixture of Windows since Windows 8 was introduced in 2012 despite a low adoption rate.  Microsoft cannot afford to have anyone get an app through their store which causes a security issue for their end users.  Even if the app was written by and uploaded to the Microsoft Store by a partner, it is Microsoft's name on the store, and they are the ones that will have reputational/brand damage if they allow something malicious into their store. Regards, Aryeh Goretsky  
    • This is more from my childhood, when nickelodeon just launched and had to license shows to have something to air. Left a big an impact, but probably more emotion positive / childhood thing. Europe got the follow up season's decade's latter with the animation studio that did Air Bender but never licenses for the US. I miss the day's of longer intro's. Nier (PS3) Intro is epic, and was very unexpected.  PS1 Xengears was also epic and an amazing game.  
    • Sayan Sen, do you think one day an image of the Windows Vista desktop or the wallpaper could be used in the primary image of an article? (When I think of CDs and DVDs I think of that release of Windows and of earlier releases; it is the one that debuted IMAPI 2.0 and other features.)
    • Big fan of EAC Here's a good non-default naming scheme I found on the web (can't take credit) File Name Scheme - %albumartist%\%year% - %albumtitle%\%tracknr2% %title% Various Artists Naming Scheme - Various Artists\%year% - %albumtitle%\%tracknr2% %title% Also, I need test but there is a new flac.exe binary & dll you can drop in the folder to upgrade flac support. I did this pre EAC 1.8. EAC 1.8 did upgrade it to 1.4.3. Flac 1.5.0 came out this year. https://ftp.osuosl.org/pub/xiph/releases/flac/ I don't know how much of a difference / impact will make.
    • Hello, Probably the simplest way of doing this would be to add a video card to your computer.   Regards, Aryeh Goretsky  
  • Recent Achievements

    • Week One Done
      maimutza earned a badge
      Week One Done
    • Week One Done
      abortretryfail earned a badge
      Week One Done
    • First Post
      Mr bot earned a badge
      First Post
    • First Post
      Bkl211 earned a badge
      First Post
    • One Year In
      Mido gaber earned a badge
      One Year In
  • Popular Contributors

    1. 1
      +primortal
      485
    2. 2
      +FloatingFatMan
      263
    3. 3
      snowy owl
      240
    4. 4
      ATLien_0
      227
    5. 5
      Edouard
      188
  • Tell a friend

    Love Neowin? Tell a friend!