radiobuttons - test if checked - why do first 2 approaches fail? - c#

I was wondering why below did not work as expected...
if if-statement changed to (!ctrl.checked) it returns all radio-button's names)
myForm f = new myForm();
foreach (RadioButton ctrl in f.Controls.OfType<RadioButton>())
{
if (ctrl.Checked)
MessageBox.Show(ctrl.Name);
}
I also tried
foreach (Control c in f.controls)
if (c is radiobutton)
{
if (c.Checked)
{
messagebox.show(c.name);
}
when I then put all radio-buttons in a group-box and used below code:
foreach (RadioButton c in groupBox1.Controls)
{
if (c.Checked)
{
MessageBox.Show(c.Name);
}
}
it worked fine.
what's the difference here.
any help appreciated


I'm guessing that your radio button is the child of a control other than the form. You need to recursively search for the radio buttons.
public void DisplayRadioButtons()
{
Form f = new Form();
RecursivelyFindRadioButtons(f);
}
private static void RecursivelyFindRadioButtons(Control control)
{
foreach (Control childControl in control.Controls)
{
RecursivelyFindRadioButtons(childControl);
if (childControl is RadioButton && ((RadioButton) childControl).Checked)
{
MessageBox.Show(childControl.Name);
}
}
}

Related

Why aren't my TextBoxes being counted?

I'm trying to change the Text in my TextBoxes in a form but I can't find out how to account for all of my TextBoxes without doing them individually...
I've tried the following code; however, my int i returns 0.
int i = 0;
foreach (Control c in this.Controls)
{
if (c.GetType().ToString() == "System.Web.UI.WebControls.TextBox")
{
i++;
((TextBox)c).Text = CleanInput(((TextBox)c).Text);
}
}
I'm just confused on how to grab all of my TextBoxes and check them...

Try this:
int i = 0;
foreach (Control c in this.Controls)
{
if (c is TextBox)
{
i++;
((TextBox)c).Text = CleanInput(((TextBox)c).Text);
}
}

If all TextBoxes are not children of "this", use a recursive method:
CleanTextBoxes(this)
private void CleanTextBoxes(Control TheControl)
{
foreach (Control c in TheControl.Controls)
{
if (c is TextBox) ((TextBox)c).Text = CleanInput(((TextBox)c).Text);
else CleanTextBoxes(c) ;
}
}

Removing a TextBox from the Controls collection has no effect

Basically what I do is: Add (n) textboxes via a button click. When I again click on it, this code runs:
foreach (Control c in this.Controls)
{
TextBox tb = c as TextBox;
if (tb != null)
{
this.Controls.Remove(tb);
tb.Dispose();
}
}
I than again add (n) textboxes, but every second item from the old textboxes remains. Any ideas?

Removing items from the collection you are iterating on is a bad idea. Try this:
List<Control> toBeRemoved = new List<Control>();
foreach (Control c in this.Controls)
{
if (c instanceof TextBox)
{
toBeRemoved.Add(c);
}
}
foreach (Control c in toBeRemoved)
{
this.Controls.Remove(c);
c.Dispose();
}

Can't loop all controls in c#

I have a C# form with some types of controls, i throught this code for loop all Labels and re-parent:
private void MakeAllLabelTrans(Control frm, Control parent)
{
foreach (Control ctl in frm.Controls)
{
if (ctl is Label)
{
ctl.Parent = parent;
// ctl.BackColor = Color.Transparent;
}
else if (ctl.HasChildren)
{
MakeAllLabelTrans(ctl, parent);
}
}
}
and call as: MakeAllLabelTrans(this, picBackground); in Form_Load event, but some label was missed (i have puted a messagebox in the loop body - it really not in the loop), but i don't know why?

You're changing the collection while enumerating it. This leads to some items being skipped.
You should rewrite this to first build a list of controls that will need to be reparented, and then reparent them in a second pass.

You should not modify the collection on which you are iterating.
private static IEnumerable<Labels> FindAllLabels(Control container)
{
foreach (Control ctl in container.Controls)
{
var lbl = ctl as Label;
if (lbl != null)
{
yield return ctl;
}
else if (ctl.HasChildren)
{
foreach (var innerResult in FindAllLabels(ctl))
yield return innerResult;
}
}
}
// now call the method like this if you want to change a property on the label
foreach (var label in FindAllLabels(theForm))
label.BackgroundColor = Color.White;
// or like this (note the .ToList()) if you want to move the labels around:
foreach (var label in FindAllLabels(theForm).ToList())
label.Parent = someOtherControl;

change property of rad controls in form

How can I access a property of rad controls in my form. something like code bellow
foreach (Control ctrl in this.Controls)
{
RadControl rc = ctrl as RadControl;
if (rc != null)
{
if (rc.GetType() == typeof(Telerik.WinControls.UI.RadButton))
{
rc.Image = ....
}
}
}
thanks

In your conditional statement you want to test if (ctrl is RadControl)
And you want to make this into a recursive function that will go down through all Control collections in the page.
private void DoSomethingToRadControls(ControlCollection controls) {
if (controls != null && controls.Any()) {
foreach (Control ctrl in controls) {
if (ctrl is RadControl) {
// do something
}
DoSomethingToRadControls(ctrl.Controls);
}
}
}

Clear all controls in a ASP.NET page with a Master page

I have a asp.net page which is inherited from a master page .I want to clear all controls in this page .I tried using the bellow method .This is not working if a master page is there. Otherwise its working fine any ideas?
private void ClearControls()
{
foreach(Control c in Page.Controls)
{
foreach (Control ctrl in c.Controls)
{
if (ctrl is TextBox)
{
((TextBox)ctrl).Text = string.Empty;
}
}
}
}

try this:
public void FindAllTextBox(Control ctrl)
{
if (ctrl != null)
{
foreach (Control c in ctrl.Controls)
{
if (c is TextBox)
((TextBox)c).Text = string.empty;
FindAllTextBox(c);
}
}
}
Ex.:
Control ctrl = this.FindControl("content");
FindAllTextBox(ctrl);

You should be able to do this with Page.Form.FindControl("ContentPlaceHolder1").Controls:
foreach (Control item in Page.Form.FindControl("ContentPlaceHolder1").Controls)
{
if (item is TextBox)
{
((TextBox)item).Text = string.Empty;
}
}

This is probably because of your controls are inside of another container when you add a master page. Have you tried adding another foreach before if?
private void ClearControls()
{
foreach(Control container in Page.Controls)
{
foreach (Control c in container.Controls)
{
foreach (Control ctrl in c.Controls)
{
if (ctrl is TextBox)
{
((TextBox)ctrl).Text = string.Empty;
}
}
}
}
}
I wouldn't do it this way though. Sometimes hardcoding is better. This would use a lot of resource when called on a page that contains lots of controls.

Don't hard code:
//Recursively get all the formControls underneath the current one, be it Page, UserControl or whatever.
public static IEnumerable<Control> GetAllControls(this Control parent)
{
foreach (Control control in parent.Controls)
{
yield return control;
foreach (Control descendant in control.GetAllControls())
{
yield return descendant;
}
}
}
Then you can call it in your webform / control:
var formCtls = this.GetAllControls().OfType<TextBox>();
foreach(TextBox txtbx in formCtls)
{
//do what you gotta do ;)
}

First, use operator as instead of is and cast:
TextBox tb = ctrl as TextBox;
if (tb != null)
{
tb.Text = String.Empty;
}
Second, you can use ITextControl instead of TextBox.
And third, try next extension method:
public static IEnumerable<T> GetChildControls(this Control control) where T : Control
{
var children = (control.Controls != null) ? control.Controls.OfType<T>() : Enumerable.Empty<T>();
return children.SelectMany(c => GetChildControls(c)).Concat(children);
}
Usage:
foreach (var c in this.Page.Controls.GetChildControls<TextBox>())
{
c.Text = String.Empty;
}

I had the same problem but I think I was making it too hard. I'm using an AJAX UpdatePanel control and I just referenced that instead of going all the way up to the MasterPage. This worked for me.
foreach (Control c in UpdatePanel1.Controls)
{
foreach (Control c1 in c.Controls)
{
if (c1 is TextBox)
{
TextBox txtBox = (TextBox)c1;
txtBox.Text = "0";
}
}
}

Just keep the controls in Panel, and try the code below
foreach (Control cntrl in pnl.Controls)//pnl is panel id
{
if (cntrl is TextBox)
{
TextBox txtBox = (TextBox)cntrl;
txtBox.Text = " ";
}
}

Make a method on your .cs like this:
//Where "this" is Page.
ClearInput(this);
private void ClearInput(Control parent)
{
foreach (Control c in parent.Controls)
{
if (c.Controls.Count > 0)
ClearInput(c);
else
{
if (c is TextBox)
(c as TextBox).Text = "";
if (c is CheckBox)
(c as CheckBox).Checked = false;
if (c is DropDownList)
(c as DropDownList).SelectedIndex = 1;
}
}
}

private void EnableControls(Control control)
{
var textbox = control as TextBox;
if (textbox != null)
{
textbox.Enabled = true;
}
var dropDownList = control as DropDownList;
if (dropDownList != null)
{
dropDownList.Enabled = true;
}
var radioButton = control as RadioButton;
if (radioButton != null)
{
radioButton.Enabled = true;
}
var checkBox = control as CheckBox;
if (checkBox != null)
{
checkBox.Enabled = true;
}
foreach (Control childControl in control.Controls)
{
EnableControls(childControl);
}
}

public void getAllCtl(ControlCollection ctls)
{
foreach (Control c in ctls)
{
if (c is System.Web.UI.WebControls.TextBox)
{
//TextBox tt = c as TextBox;
////to do something by using textBox tt.
((TextBox)c).Text = string.Empty;
}
if (c is System.Web.UI.WebControls.CheckBox)
{
((CheckBox)c).Checked = false;
}
if (c is System.Web.UI.WebControls.DropDownList)
{
((DropDownList)c).SelectedIndex = -1;
}
if (c.HasControls())
{
getAllCtl(c.Controls);
}
}
}
calling in aspx.cs file as
getAllCtl(this.Form.Controls);
This is OK and tested work for all Master-child page and where ever multiple controls are contains in the page...

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