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Getting list of checked radiobuttons in .net

TLDR; Looking for a method to retrieve all radiobuttons by means of something like this... (psudo)
List<RadioButton> btn = new List<RadioButton>;
btn = stackPanel.getAllRadioButtons()
I am currently building a little quiz application in C#. I have functions that add the required GUI elements to a groupbox. I would like to know if there is any way that I can loop through the created elements (for instance radio buttons) to see which are checked.
Here is one of the functions along with how they are added to the window.
private void tfQ(string questionBody)
{
StackPanel questionPanel = new StackPanel{Orientation = Orientation.Vertical};
questionPanel.Children.Add(new Label { Content = questionBody });
GroupBox group = new GroupBox();
RadioButton trueRadio = new RadioButton();
trueRadio.Content = "True";
RadioButton falseRadio = new RadioButton();
falseRadio.Content = "False";
questionPanel.Children.Add(trueRadio);
questionPanel.Children.Add(falseRadio);
group.Content = questionPanel;
mainStack.Children.Add(group);
}
Constructor:
public quiz()
{
tfQ("This is a true/false question");
Window w = new Window();
w.Content = mainStack;
w.Show();
}
I have found many ways to do it in the C# scripting format
(using the Control function ...)
var checkedButton = container.Controls.OfType<RadioButton>()
.FirstOrDefault(r => r.Checked);
but I have not yet found a "programmatic" way of doing it. I have considered changing the type of void tfQ to a StackPanel, but that only helps me to easier loop through the stack panels, althought that only partly solves me problem - allows me to easier loop through the StackPanels but I still don't know how to get the RadioButtons on a panel.
P.S I am very new to C# - with experience in Java/C/C++/Python

I made use of the following code to cast the content into a new groupbox and stackpanel, respectively.
if (child is GroupBox)
{
if ((child as GroupBox).Content is StackPanel)
{
StackPanel d = (StackPanel)((GroupBox)child).Content;
}
}
This allowed me to cast the content into a local copy of a control. It may not be the best way - I'm sure it is very inefficient to be honest. Solved the problem.

Adding a twin tabPage to tabControl through a user command

I'm a newbie in c# and probably going to ask a very easy question, but I've not been able to find anything on the web to help.
I have a tabControl with a TabPage which is containing a TextBox object; this object, when the event "Text changed" is invoked, will perform the change of the parent tabPage's name.
The textbox where I typed "text changed by me" has a method which is managing changing the name of the tabPage:
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (this.textBox1.Text != "")
this.tabControl2.SelectedTab.Text = this.textBox1.Text;
else
this.tabControl2.SelectedTab.Text = "(no name)";
}
Into the current page menu is contained a control to add a new page, which runs this method when the user click on it:
private void addNewPageToolStripMenuItem_Click(object sender, EventArgs e)
{
int numPagine;
string strPagine;
numPagine = this.tabControl2.TabCount;
strPagine = numPagine.ToString();
this.tabControl2.TabPages.Add("new page" + strPagine);
}
...and here is the output, which is expected since I'm just asking to add a new empty tabPage:
So, my question is: how can I make possible that when the user is clicking on "Add new page", rather than creating an empty new tabPage the program is rather creating a page like the first one (i.e. containing a textbox into the same position which has a method to change the text of the parent tabPage that I have just created?

Here is an example.
//..
// create the new page
TabPage tpNew = new TabPage("new page..");
// add it to the tab
this.tabControl2.TabPages.Add(tpNew);
// create one labe with text and location like label1
Label lbl = new Label();
lbl.Text = label1.Text;
lbl.Location = label1.Location;
// create a new textbox..
TextBox tbx = new TextBox();
tbx.Location = textBox1.Location;
tpNew.Controls.Add(lbl);
tpNew.Controls.Add(tbx);
// add code to the new textbox via lambda code:
tbx.TextChanged += ( (sender2, evArgs) =>
{
if (tbx.Text != "")
this.tabControl2.SelectedTab.Text = tbx.Text;
else
this.tabControl2.SelectedTab.Text = "(no name)";
} );
For more complicated layout you may want to consider creating a user control..
You also may want to create the first page with this code; the, of course with real values for text and positions!
For creating a UserControl you go to the project tag and right click Add-UserControl-UserControl and name it, maybe myTagPageUC. Then you can do layout on it like on a form. A rather good example is right here on MSDN
The problem is that is has no connection to the form, meaning you'll have to code all sorts of references to make it work..
I'm not really sure if you may not be better off writing a complete clonePage method instead. It could work like the code above, but would loop over the Controls of the template page and check on the various types to add the right controls..
It really depends on what is more complicated: the Layout or the ties between the pages and the form and its other controls..

Can I give controls an index property in C# like in VB?

I've found similar answers to my question before, but not quite to what I'm trying to do...
In Visual Basic (last I used it, in 06/07) there was an "Index" property you could assign to multiple controls with the same name. I used this primarily to loop through controls, i.e.:
For i = 1 to 500
picSeat(i).Print "Hello"
Next i
Is there a way to do this in C#? I know there is a .IndexOf(), but would that really help for what I'm doing? I want to have multiple controls with the same name, just different index.
This is a Windows Form Application, and I'm using Visual Studio 2012. I am talking about controls, not arrays/lists; this was possible in VB and I was wondering if it was possible at all in C#. So I want to have, say, 30 seats in a theatre. I want to have each seat represented by a picturebox named "picSeat". VB would let me name several objects the exact same, and would assign a value to a control property "Index". That way, I could use the above loop to print "Hello" in every picture box with only 3 lines of code.

No, this feature does not exist in C#, and was never implemented in the transition from classic VB to VB.Net.
What I normally do instead is put each of the controls in question in a common parent container. The Form itself can work, but if you need to distinguish these from others of the same type a GroupBox or Panel control will work, too. Then, you access the controls like this:
foreach (var picBox in parentControl.Controls.OfType<PictureBox>())
{
// do something with each picturebox
}
If you want to use a specific control, just write by name:
pictureBox6.SomeProperty = someValue;
If you need to change a specific control determined at run-time, normally this is in response to a user event:
void PictureBox_Click(object sender, EventArgs e)
{
var picBox = sender As PictureBox;
if (picBox == null) return;
//picBox is now whichever box was clicked
// (assuming you set all your pictureboxes to use this handler)
}
If you really really want the Control Arrays feature, you can do it by adding code to create the array to your form's Load event:
PictureBox[] pictureBoxes = Me.Controls.OfType<PictureBox>().ToArray();

Are we talking WinForms here? I'm not sure, but I don't think you can have multiple controls in winforms with same name. But I vaguely recall doing something similar and the solution was to name them Button_1, Button_2 etc. Then you can iterate through all controls and get your own index.
Beware though that if you want to instanciate a separate control for each seat in a theatre, you might run into some serious performance issues :) I've done something similar to that as well and ended up drawing the whole thing on a canvas and using mouse coordinates to handle the events correctly.

You may want to check out the Uid property of controls.
(http://msdn.microsoft.com/en-us/library/system.windows.uielement.uid(v=vs.110).aspx)
You can access Control through Uid property with the following
private static UIElement FindUid(this DependencyObject parent, string uid)
{
var count = VisualTreeHelper.GetChildrenCount(parent);
if (count == 0) return null;
for (int i = 0; i < count; i++)
{
var el = VisualTreeHelper.GetChild(parent, i) as UIElement;
if (el == null) continue;
if (el.Uid == uid) return el;
el = el.FindUid(uid);
if (el != null) return el;
}
return null;
}
And simply use
var control = FindUid("someUid");
I copied code from this post

If you create an indexed dictionary of your user control, it will behave pretty much the same as in VB6, though you'll not see it on the VS C# GUI. You'll have to get around the placement issues manually. Still - and most importantly -, you'll be able to refer to any instance by the index.
The following example is for 3 pieces for clarity, but of course you could automate every step of the process with appropriate loops.
public partial class Form1 : Form
{
...
Dictionary<int, UserControl1> NameOfUserControlInstance = new Dictionary<int, UserControl1>()
{
{ 1, new UserControl1 {}},
{ 2, new UserControl1 {}},
{ 3, new UserControl1 {}}
};
private void Form1_Load(object sender, EventArgs e)
{
NameOfUserControlInstance[1].Location = new System.Drawing.Point(0, 0);
NameOfUserControlInstance[2].Location = new System.Drawing.Point(200, 0);
NameOfUserControlInstance[3].Location = new System.Drawing.Point(400, 0);
Controls.Add(NameOfUserControlInstance[1]);
Controls.Add(NameOfUserControlInstance[2]);
Controls.Add(NameOfUserControlInstance[3]);
}
...
}

I like using Tags to apply any type of meta data about the controls
for (int i = 0; i< 10; ++i)
{
Button button = new Button();
button.Tag = i;
}

Making an indexed control array?

Has C# indexed control arrays or not? I would like to put a "button array" for example with 5 buttons which use just one event handler which handles the index of all this 5 controls (like VB6 does). Else I have to write for each of these 5 buttons one extra event handler. And if I have 100 buttons, I need 100 event handlers? I mean something like that:
TextBox1[i].Text="Example";
It could make coding definitely easier for me to work with control arrays. Now I have seen, that C# at least has no visible array functionality on user controls and no "index" property on the user controls. So I guess C# has no control arrays, or I must each element call by known name.
Instead of giving 100 TextBoxes in a for loop 100 incrementing values, I have to write:
TextBox1.Text = Value1;
TextBox2.Text = Value2;
...
...
TextBox100.Text = Value100;
A lot of more work + all these 100 event handlers each for one additional TextBox extra.

I know I'm a little late to this party, but this solution will work:
Make a global array:
TextBox[] myTextBox;
Then in your object's constructor, after the call to
InitializeComponent();
initialize your array:
myTextBox = new TextBox[] {TextBox1, TextBox2, ... };
Now you can iterate your array of controls:
for(int i = 0; i < myTextBox.Length; i++)
myTextBox[i].Text = "OMG IT WORKS!!!";
I hope this helps!
Pete

As I mentioned in comment to a solution by HatSoft, C# Winforms does not allow you to create control arrays like old VB6 allowed us. The nearest I think we can get to is what HatSoft and Bert Evans in their posts have shown.
One thing that I hope would satisfy your requirement is the event handler, you get a common event handler and in the event handler when you typecast the "sender" you get the control directly just like you would in VB6
C#
TextBox textBox = sender as TextBox;
VB6
TextBox textBox = TextBox1[i];
So the only trouble you might have is wiring those 100 TextBoxes to a single event handler, if you are not creating the controls dynamically through code rather creating it manually at design time then all one can suggest is group them in a container like say Panel. Then on Form Load wire them all up to a single event handler like this:
foreach (Control control in myTextBoxPanel.Controls)
{
if(control is TextBox)
control.TextChanged += new EventHandler(control_TextChanged);
}

Just create one handler and point all the buttons to it.
var ButtonHandler = (sender, args) => {
var clicked = (Button)sender;
if (clicked.Text == "whatever")
//do stuff
else
//do other stuff
};
button1.Click += ButtonHandler;
button2.Click += ButtonHandler;
Alternatively, if you are creating controls in code, you could use one of the techniques specified in this answer.

Instead of giving 100 TextBoxes in a for loop 100 incrementing values, I have to write:
for(int i = 0; i <100; i++)
{
TextBox t = new TextBox(){ Id = "txt_" + i, Value = "txt_" + i};
t.TextChanged += new System.EventHandler(this.textBox_Textchanged);
Page.Controls.Add(t);
}
//and for event on TextChanged
private void textBox_Textchanged(object sender, EventArgs e)
{
TextBox textBox = sender as TextBox;
if (textBox != null)
{
////
}
}

Another thing to note: if you really need to edit 100 strings on one form, you should probably think about whether 100 text boxes is really the best way to do it. Perhaps a ListView, DataGridView, or PropertyGrid would be better suited.
This applies almost any time you think you need a huge array of controls.

If you are working with Web Forms and not MVC, you can acces a collection of controls on the page as shown in Using the Controls Collection in an ASP.NET Web Page. Essentially the controls collection is a tree with the page hosting the first level of child controls and some items having children of their own. See How to: Locate the Web Forms Controls on a Page by Walking the Controls Collection for an example of how to follow the tree.
Also, see How to: Add Controls to an ASP.NET Web Page Programmatically.
You can use the same event handler for multiple items as long as the signature required is the same.
For Windows Forms this is nearly identical since they're based on similar architectural models, but you'll want Control.Controls Property and How to: Add Controls to Windows Forms.

Keeping it simple:
TextBox[] keybox = new TextBox[16]; //create an array
for (int i=0; i<16; i++)
{
keybox[i] = new TextBox(); //initialize (create storage for elements)
keybox[i].Tag = i; //Tag prop = index (not available at design time)
keybox[i].KeyDown += keybox_down; //define event handler for array
}
private void keybox_down(object sender, KeyEventArgs e)
{
int index = (int)((TextBox)sender).Tag //get index of element that fired event
...
}

Creating a dynamic UI in winforms

If I want to create a winform with dynamic UI controls appearing, what's the best way to do that?
I have a form with a textbox, a button1 to the right of it, a listbox underneath, and a button2 underneath the listbox. Pressing button1 should generate another textbox underneath the first textbox and the listbox/button2 should be shifted down. If anyone's used Adobe Bridge before, the batch rename window is an example of what I'm talking about.
I was thinking of simply adding textboxN.Height to this.Size, then textboxN.Height to each of the controls (except the first textbox) Y position so they all get shifted down by textboxN.Height pixels. But I think there's a better way of doing this. Rather, is Winforms suitable for something like this?

You -could- just add the height of the TextBox to the form's size, but tbh it would be better to use a constant that dictates the size of the TextBoxes, and then add that.
For moving the listBox/button2, anchor them to the bottom of the form, and they'll automatically stay at the same distance from the bottom of the form.
As for dynamic generation, use a List (or a Stack, depending on what exactly you're doing with it).
partial class Form1 : Form
{
List<TextBox> textBoxes = new List<TextBox>(); // or stack
const int textBoxWidth = 200; // control variables for TextBox placement
const int textBoxHeight = 50;
const int textBoxMargin = 5;
void button1_Click(object sender, EventArgs e)
{
this.Height += textBoxHeight + textBoxMargin;
TextBox tb = new TextBox();
if (textBoxes.Count == 0)
{
tb.Top = textBoxMargin;
}
else
{
tb.Top = ((textBoxHeight + textBoxMargin) * textBoxes.Count) + textBoxMargin;
}
tb.Left = textBoxMargin;
tb.Height = textBoxHeight;
tb.Width = textBoxWidth;
textBoxes.Add(tb);
this.Controls.Add(tb);
}
}
That should work. The thing with the method here is pretty much all of the placement customisation can be done with the constant values.
Is it best to do it in WinForms? Well, there's certainly no real reason to not do it in WinForms, this functionality is easy enough to implement. I'm a WPF guy myself but this is still legit.
Edited for logic errors