C# Discussion Boards - CodeProject

16-Dec-09 13:51

The problem:

1. Start a new (Windows Forms Application) Project in Visual C#
2. Drag a Button onto the main window "Form1", and give it a name, "button1"
3. Drag another Button onto the main window, and give it a name, "button2"

Now the project consists of a main window and two push buttons.

How can I create a collection of these graphical widgets (actually, references to the widgets, since the widgets already exist) such that I would be able to:

1) iterate through the collection, and access each items' methods and attributes.

2) access any graphical widget in the collection by its name.

Is this possible in C#? Thanks for any help.

PIEBALDconsult16-Dec-09 13:56

PIEBALDconsult

16-Dec-09 13:56

Yes.

cron-fed16-Dec-09 14:26

16-Dec-09 14:26

How?

PIEBALDconsult16-Dec-09 17:09

PIEBALDconsult

16-Dec-09 17:09

I'd define what exactly I want and then write some code.

_Maxxx_16-Dec-09 14:29

_Maxxx_

16-Dec-09 14:29

You'll find your form has a collection called 'Controls' which you can iterate over. Each element is a Control (Button, textbox etc.) which you can cast to the correct type and access its properties.

foreach (Control control in Controls)
{
    if (control is Button)
    {
        ((Button)control).PerformClick();
    }
}

Probably not the best way to do it - but it depends what your requirements actually are..,,

Accessing a control by its name is what you normally do?

Button1.Text = "Hello World";

for example.

___________________________________________
.\\axxx
(That's an 'M')

BillWoodruff16-Dec-09 15:30

BillWoodruff

16-Dec-09 15:30

Hi Cron-Fed,

I, and I am sure others here, will be happy to help you, but your question here, imho, could be clarified.

What is the final result you are after here : do you want :

1. an application with one form which contains (is the parent of) of identical widget forms ?

2. an application which has one "master form" or "main window" which then creates one or more of your widget forms as "independent" external windows : and manages them ?

3. an application where there are a bunch of "independent" widget forms each identical. each having "knowledge of" or the ability to send and receive "messages" to ? i.e., : there's no one "main" or "master form" ?

My intuition here is that you are talking about wanting a collection of UserControls, but I'm not psychic Smile | :)

Please describe more precisely what you want to see on the screen when you launch your application.

best, Bill

"Many : not conversant with mathematical studies, imagine that because it [the Analytical Engine] is to give results in numerical notation, its processes must consequently be arithmetical, numerical, rather than algebraical and analytical. This is an error. The engine can arrange and combine numerical quantities as if they were letters or any other general symbols; and it fact it might bring out its results in algebraical notation, were provisions made accordingly." Ada, Countess Lovelace, 1844

Subin Mavunkal16-Dec-09 20:23

Subin Mavunkal

16-Dec-09 20:23

Hi ,
I guess you want to reuse that form again and again...right ?If you can create a user control...that will do the trick.Am I right ? Smile | :)

cron-fed17-Dec-09 7:15

[SOLVED]Re: Creating a Collection of Widgets

17-Dec-09 7:15

My goal is to be able to:

- access each graphical widget by instance name (Tag or Text attribute)
- change each widget's attributes according to an external data source

The "external data source" will be a class that parses a windows .ini file, that contains attribute,value pairings. Something like:

[Button_001]
type = toggle_button;
on_text = "On";
off_text = "Off";
on_color = "Red";
off_color = "White";
etc. etc.

where "Button_001" is the Tag or Text attribute of a button widget already placed in the gui.

cron-fed17-Dec-09 9:16

Re: Creating a Collection of Widgets [modified]

17-Dec-09 9:16

I found a good relevant starting point project:

http://www.codeproject.com/KB/miscctrl/ControlsIteration.aspx

Thanks everyone for your replies.

BillWoodruff18-Dec-09 13:37

BillWoodruff

18-Dec-09 13:37

Hi Cron-Fed,

Looking at all the posts on this thread, I'm still not as clear about what you are doing as I'd like to be.

So here's a few final comments just based on "intuition" :

1. the business of reading in from an .ini file to construct a whole set of components seems to me like something that would fit "naturally" with using XML : using XML files and capabilities you can save and restore whole hierarchies easily.

2. my guess is this what you are after here is a way to serialize and de-serialize a whole bunch of controls (possibly nested) : do look around CP for serialize and deserialize examples.

3. my guess is you may want to think about a TreeView as a container for your "overview" of Controls rather than a just a ComboList : after all using a TreeView will map naturally to nested collections of Controls. It will also "map naturally" to hierarchies expressed in XML. I'm pretty sure CP has some articles on saving and restoring TreeView nodes and content.

4. you can actually use the Winforms PropertyGrid control on a WinForm Application at run-time to show you all the properties of any control in the same way you see them at design-time : you can even edit the properties :

set the SelectedObject property on the PropertyGrid to the Control you want to display the properties of :

note this control, must use Reflection to reconstruct the properties and to enable dynamic round-trip updating : can be slow it used at run-time.

good luck, Bill

modified on Friday, December 18, 2009 7:44 PM

Updates wrong table in dataset

Star0916-Dec-09 12:50

Star09

16-Dec-09 12:50

Hello,

System.Data.OleDb.OleDbCommandBuilder cb = new System.Data.OleDb.OleDbCommandBuilder(dAdapter);

 if (current_list == "list1")
{
    DataRow row = myset.Tables["list"].NewRow();

    int y;
    y = myset.Tables["list"].Rows.Count;

    row["ID"] = y + 1;
    row["word"] = s; // s is user input
    row["perc"] = 0.5;

     myset.Tables["list"].Rows.Add(row);

    dAdapter.Update(myset, "list");

}

I used break points to confirm that the data is updated here, however, for some reason when I check the database another table is updated instead of "list"

Where could be the problem? I checked the code several times, but I'm not sure Confused | :confused:

Re: Updates wrong table in dataset

Paulo Zemek17-Dec-09 1:09

Paulo Zemek

17-Dec-09 1:09

I don't use dataadapters or datatables, for me they are legacy. But, how is the command of the dataadapter built?

If you pass a custom SQL to the data-adapter (I really don't know if this is the case), that could be the cause, not the code block you showed here, as here the data adapter already exists.

Can't multiply...

o m n i16-Dec-09 10:57

o m n i

16-Dec-09 10:57

All the sudden, the compiler is complaining everywhere I've used the * symbol to multiply "The * or -> operator must be applied to a pointer". I don't even have unsafe code enabled so whats going on?

Richard MacCutchan16-Dec-09 11:04

Richard MacCutchan

16-Dec-09 11:04

Omnicoder wrote:
All the sudden, the compiler is complaining everywhere I've used the * symbol to multiply "The * or -> operator must be applied to a pointer".

Your expression is wrong; possibly you are trying to multiply a non-numeric value, or an object that does not have an operator* overload. Maybe if you showed a few lines of code to demonstrate the problem we can give a more definitive answer.

o m n i16-Dec-09 11:06

o m n i

16-Dec-09 11:06

Even simple things like this break it.

int num1 = 0;
int num2 = 7;
return (num1 * num2);

loyal ginger16-Dec-09 11:23

loyal ginger

16-Dec-09 11:23

How about creating a new very simple project with just the above three lines in one function. I am sure it will work. Somewhere in your program * messed up something.

Richard MacCutchan16-Dec-09 11:43

Richard MacCutchan

16-Dec-09 11:43

Assuming that this is an entire project then I guess something is corrupt in your compiler or your system include files, but it's impossible to say what.