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Thread ID: 99426 2009-05-01 11:45:00 C# help! WarNox (8772) Press F1
Post ID Timestamp Content User
769982 2009-05-01 11:45:00 Hey!

Ok this is driving me crazy, I've spent a good 2 hours trying to research it but came up with nothing.

I'm trying to use a String to refer to a TextBox, kind of a dynamic name.

eg.

Say I have:

Textbox1
Textbox2
Textbox3

...on a form and then I want to call a method with the text from each of those textboxes. So I want a loop to do:



String a = "Textbox" + counter.ToString();
methodToCall(a.Text);

Of course that doesn't work. But how can I convert String A into something that the compiler will recognise as a TextBox object!?

Hope this makes sense.

ps. I tried using a Control mycontrol = FindControl.... -> but my visual studio will cannot find 'FindControl'.

Thanks,




Gregor 		WarNox (8772)
769983 2009-05-01 20:27:00 I haven't used c#, but drawing on some parallels with MSAccess...

Instead of myControl, what about currentControl or currentObject

obviously move the 'focus' to the text box before applying this. 		Paul.Cov (425)
769984 2009-05-01 20:42:00 Hey!

Ok this is driving me crazy, I've spent a good 2 hours trying to research it but came up with nothing.

I'm trying to use a String to refer to a TextBox, kind of a dynamic name.

eg.

Say I have:

Textbox1
Textbox2
Textbox3

...on a form and then I want to call a method with the text from each of those textboxes. So I want a loop to do:



String a = "Textbox" + counter.ToString();
methodToCall(a.Text);

Of course that doesn't work. But how can I convert String A into something that the compiler will recognise as a TextBox object!?

Hope this makes sense.

ps. I tried using a Control mycontrol = FindControl.... -> but my visual studio will cannot find 'FindControl'.

Thanks,

Gregor

The easiest way is to use the FindControl().

So:




for (int i = 1; i < 4; i++){
TextBox t = (TextBox)this.FindControl("Textbox" + i);
methodToCall(t.Text);
}
Note: You'll need to add some checks to make sure the returned object isn't null.


You could also try accessing the Controls collection directly: www.csharpfriends.com 		somebody (208)
769985 2009-05-02 05:07:00 Cool, thanks for the replies guys! I'll give this a try and see how I go!



Gregor 		WarNox (8772)
769986 2009-05-02 05:20:00 Cool, thanks for the replies guys! I'll give this a try and see how I go!



Gregor

Out of curiosity, why are you wanting to dynamically reference the textbox controls at all?

You should really give the textboxes more meaningful names - for example "phoneNumberTextBox" or "txtPhoneNum" (depending on what naming convention you prefer) - so that when you come back to read your code in 6 months time, you actually know what it is referring to. 		somebody (208)
769987 2009-05-02 05:40:00 Because I want the program to move from one text box to another and do stuff, rather than referring to each one individually.

---

Hmm, well I got it to work using:


this.Controls[whichPc].Text

but I cannot use the same sort of method for an OvalShape or a ProgressBar. I've also tried doing it the FindControl way but my VS2008 does not recognize FindControl as a valid method!?

I've added these two lines at the top but still no luck:


using System.Windows.Forms;
using System.Web.UI; 		WarNox (8772)
769988 2009-05-02 05:51:00 Because I want the program to move from one text box to another and do stuff, rather than referring to each one individually.

---

Hmm, well I got it to work using:


this.Controls[whichPc].Text

but I cannot use the same sort of method for an OvalShape or a ProgressBar. I've also tried doing it the FindControl way but my VS2008 does not recognize FindControl as a valid method!?

I've added these two lines at the top but still no luck:


using System.Windows.Forms;
using System.Web.UI;

When you say you can't do the same thing with an OvalShape or a ProgressBar, are you casting the returned object to the right datatype?

For example:
ProgressBar pg = this.Controls["Progressbar1"] as ProgressBar;
pg.Width = 100; 		somebody (208)
769989 2009-05-02 06:19:00 Well I tried to get an OvalShape to turn green so I did:


this.Controls["ovalShape" + counter.toString()].FillColor = Color.Green;

Fails on 'FillColor'.


this.Controls["progressBar" + counter.toString()].Value = '100';

This fails on 'Value'

---

But I can't get the FindControl to work in any way or form :S 		WarNox (8772)
769990 2009-05-02 06:43:00 Well I tried to get an OvalShape to turn green so I did:


this.Controls["ovalShape" + counter.toString()].FillColor = Color.Green;

Fails on 'FillColor'.


this.Controls["progressBar" + counter.toString()].Value = '100';

This fails on 'Value'

---

But I can't get the FindControl to work in any way or form :S

The problem is that the objects in the Controls collection are of the supertype "Control" - and therefore do not have FillColor or Value properties.

You need to cast the returned object to the appropriate datatype first - so for example:



ProgressBar pg = this.Controls["progressBar" + counter.toString()] as ProgressBar;
pg.Value=100;


Note the "as ProgressBar" at the end of that first line - what that is doing is it's casting the "Control" returned from the collection into a "ProgressBar" datatype, which you can then access the .Value property with.

Just a quick question so I know how much detail/explanation to give next time: how much programming experience have you had (with C#, and in general)? 		somebody (208)
769991 2009-05-02 06:54:00 Oh I've done a fair bit of work with c# but it's been a year or two since i last touched it so yeah. I've moved towards networking/servers lately but I like to do a little project every now and then.

---

Ok that makes sense. I'm bound to come back here with further issues :)

Thanks for all the help. 		WarNox (8772)
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