I have tons of Buttons named like this x0y1
How do I access the variable name dynamically so I could loop all names by xiy1 or so.
in PHP it would be like ${"myString" . $randomvar}
I can't use a list or array because the the button already exist defined through the xaml
You can use:
var textbox =
this.Controls.OfType<TextBox>().Where(txb => txb.Name == "myString").FirstOrDefault();
This assumes you are in the context of your form (this.Controls).
And of course, don't forget to add using System.Linq;...
You can get all the textbox using this method
void AllTextBox(System.Windows.Forms.Control.ControlCollection ctrls)
{
foreach (Control ctrl in ctrls)
{
if (ctrl is TextBox)
{
if (ctrl.Name == "textBox1")
{
// do your stuf with textbox
}
}
}
}
You can create function that return control by name :
Control GetControlByName(string Name)
{
foreach(Control control in this.Controls)
if(c.Name == Name) return control ;
return null;
}
or Function with a specific control like that :
Button GetButtonByName(string Name)
{
foreach (Control c in this.Controls.OfType<Button>())
if (c.Name == Name) return c;
return null;
}
For wpf project...
Let's say you have a grid named MyGrid and there's lot of buttons on it.
You want to refer to the button named x0y1:
var btn = MyGrid.Children.OfType<Button>().Where(x=>x.Name=="x0y1");
Note: above code should work for flat structure (one level deep only).
You can achieve the same by using code provided in this thread: How can I find WPF controls by name or type?
Just call FindName("elementName"). FindName searches through all child elements of a FrameworkElement. To access any button by its name as string in a window, call the FindName() method of the window !
If your code is in a class inheriting from Window, just use:
Button button = (Button)FindName("xiy1");
If you write the code in a class not inheriting from Window but FrameworkElement, which is unlikely, use:
Window window = Window.GetWindow(this);
Button button = (Button)window.FindName("xiy1");
Check the MSDN documentation about Namescopes for more information about limitations.
Related
I have a Placeholder and I have a dynamically created panel in the placeholder, I also have some dynamically added radio buttons in the panel, now I can usefindControl() to find the radio buttons if they are direct children of the placeholder.
I've literally spent the whole of yesterday trying to find them when they are the child elements of the Panel. How is there a way to do this?
Here's my code below:
PlaceHolder1.Controls.Add(myPanel); //add the panel to the placeholderenter code here
myPanel.Controls.Add(myRadioButton); //add the radiobutton to the panel
You should make method that recursively searches for a control using it's Id. That mean that the method will search for a control inside of (in your case) placeholder. If method finds control, it will return it. If not, it will go search every placeholder's subcontrol, going "deeper". And then, if nothing is found, it will search one more level down, in every placeholder subcontrols' subcontrol etc.)
private Control FindControl(string ctlToFindId, Control parentControl)
{
foreach (Control ctl in parentControl.Controls)
{
if (ctl.Id == ctlToFindId)
return ctl;
}
if (ctl.Controls != null)
{
var c = FindControl(ctlToFindId, ctl);
if (c != null) return c;
}
return null;
}
and then use it like this:
Control ctlToFind = FindControl(myRadioButton.Id, Placeholder1);
if (ctlToFind != null)
{
//your radibutton is found, do your stuff here
}
else
{
// not found :(
}
Finding Controls recursive is an option, but it also has a couple of down-sides.
If you know the ID's of all the controls you can just use FindControl
RadioButtonList myRadioButton = PlaceHolder1.FindControl("Panel1").FindControl("RadioButtonList1") as RadioButtonList;
Label1.Text = myRadioButton.SelectedValue;
But you will need to give your dynamically added controls an ID.
Panel myPanel = new Panel();
myPanel.ID = "Panel1";
RadioButtonList myRadioButton = new RadioButtonList();
myRadioButton.ID = "RadioButtonList1";
PlaceHolder1.Controls.Add(myPanel);
myPanel.Controls.Add(myRadioButton);
I'm good with Loading the control, using the LoadControl("~/vitrualPath"), so I have:
UserControl ctrl = (UserControl)LoadControl("~/controls/someControl.ascx");
this.Controls.Add(ctrl);
//plcCtrl.Controls.Add(ctrl);
The trouble is that I wish to then loop through all the controls in the usercontrol:
foreach (Label c in this.Controls.OfType<Label>())
{
// It's a label for an input
if (c.ID.Substring(0, 8) == "lblInput")
{
// Do some stuff with the control here
}
}
However, the added controls aren't part of this, but part of ctrl
Is there a way I can add the contents of the loaded control to this or a way to loop through both this and ctrl in one hit?
If you simply want to loop through both top-level labels and labels in ctrl, try this.Controls.Concat(ctrl.Controls).OfType<Label>() in your foreach loop.
You can also move your if into a LINQ Where call:
.Where(l => l.ID.Substring(0, 8) == "lblInput")
By using a recursive function you don't need to worry about controls within sub levels/ containers. Something like this should be OK (all you need to do is to pass the top level control along with the id substring that you are interested in). So if the conditions are met it will do whatever you have intended to do with the control and at any sub level.
public void ProcessControl(Control control, string ctrlName)
{
foreach (Label c in control.Controls.OfType<Label>())
{
// It's a label for an input
if (c.ID.Substring(0, 8) == ctrlName)
{
// Do some stuff with the control here
}
}
foreach (Control ctrl in control.Controls)
{
ProcessControl(ctrl, ctrlName);
}
}
You should write a recursive method that starts looping the controls in this.Controls and goes down the tree of controls. It will then also go in your user control and find your labels.
I don't think there is a way to loop through both like you want.
You can easily create a method that receives a Control as parameter and iterate though its controls. Something like this:
void Function(Control control)
{
foreach (Label c in control.Controls.OfType<Label>())
{
// It's a label for an input
if (c.ID.Substring(0, 8) == "lblInput")
{
// Do some stuff with the control here
}
}
}
You should be able to access the controls inside the user control by accessing the this.Controls[index].Controls I think, however it kind of depends what you are trying to achieve? Their might be a cleaner way of doing what you are trying to do?
I have many buttons and labels on my c# form. I have a button that changes all butons' and labels' text properties (change language button). Do i have to write all items in click event of button or is there a method that scans all form control items and change their text properties.
There are many other controls that contains labels or buttons. For example a label is added to the control of a panel and when i iterate form controls, i can't reach this label. I want to change all items' text properties at one time.
Thank you.
foreach (Control objCtrl in yourFormName.Controls) {
if (objCtrl is Label)
{
// Assign Some Text
}
if (objCtrl is Button)
{
// Assign some text
}
}
If a CS0120 error happens, change yourFormName.Controls to this.Controls;
Assuming ASP.NET's ITextControl Interface (works similar for Winforms-Controls' Text-Property ):
var text = "Hello World";
var allTextControls = this.Controls.OfType<ITextControl>();
foreach(ITextControl txt in allTextControls)
txt.Text = text;
http://msdn.microsoft.com/en-us/library/bb360913.aspx
Edit: You could easily make it an extension(e.g. ASP.NET, for Winforms replace ITextControl with Control):
public static class ControlExtensions
{
public static void SetControlChildText(this Control rootControl, String text, bool recursive)
{
var allChildTextControls = rootControl.Controls.OfType<ITextControl>();
foreach (ITextControl txt in allChildTextControls)
txt.Text = text;
if (recursive) {
foreach (Control child in rootControl.Controls)
child.SetControlChildText(text, true);
}
}
}
Now you can call it for example in this way:
protected void Page_Load(object sender, EventArgs e)
{
Page.SetControlChildText("Hello World", true);
}
This will apply the given text on every child control implementing ITextControl(like Label or TextBox).
If it's winforms you should read about localizing your application here:
Walkthrough: Localizing Windows Forms
I think if you are using javascript, you can simply go through the DOM and modify the texts of the buttons and labels. Using jQuery this will be very simple
For a web application, you could do this quite easily with jQuery. Have a look at this: http://api.jquery.com/category/selectors/
$('label').each(function(){this.value = 'something else';});
For Winforms, you can use this:
foreach (var c in Controls.OfType<TextBox>())
c.Text = "TextBox Text";
foreach (var c in Controls.OfType<Label>())
c.Text = "Label text";
But I agree with #ionden, you should consider localizing your application.
There is a Controls property that contains all controls of your form. You can iterate over it:
foreach(var control in Controls)
{
var button = control as Button;
if(button != null)
button.Text = Translate(button.Text);
else
{
var label = control as Label;
if(label != null)
label .Text = Translate(label .Text);
}
}
foreach( Control ctlparent in this.Controls)
{
if(ctlparent is Panel or ctlparent is GroupBox)
{
foreach(Control ctl in ctlparent.Controls)
{
if(ctl is Label or ctl is Button)
{
ctl.Text= newtext;
}
}}
This will work.
I have seen many others with similar problems but I cannot find the flaw in my logic here. Any help would be greatly appreciated.
I have a Panel which I have added numerous label and textbox controls to, ie:
myPanel.Controls.Add(txtBox);
These controls are created and added in a method called previous to the iteration method.
I want to iterate through each textbox and use its Text property as a parameter in another method but I am not having any luck. Here is my attempt to iterate:
public void updateQuestions()
{
try
{
foreach (Control c in editQuestionsPanel.Controls)
{
if (c is TextBox)
{
TextBox questionTextBox = (TextBox)c;
string question = questionTextBox.Text;
writeNewQuestionToTblQuestions(question);
}
}
}
catch (Exception err)
{
Console.WriteLine(err.Message);
}
}
The problem I am having is that the controls are not in the Panel when I arrive at this updateQuestions() method. Here is the process involved:
A commandButton is clicked and the questions are read from a DB, for each question a method is called which adds 2 labels and a textbox to editQuestionsPanel.Controls. This panel is inside a PlaceHolder which is then made visible.
When a button inside the PlaceHolder is clicked, the updateQuestions() method is called and the editQuestionsPanel.Controls.Count = 1. As there are approx 12 questions in the DB it should be around 36. The one control inside the Panel is of type:
System.Web.UI.LiteralControl
It contains no controls.
I am sure that somwhere in the lifecycle the Panel's controls are being cleared but I do not know how to step thru the life cycle. I have a Page_load method which is called as soon as a button is clicked but once the button which calls updateQuestions() is clicked the editQuestionsPanel.Controls.Count is already back to 1 so it must be cleared before this but I do not know how to correct this...
Any help you can give to help me solve this would be greatly appreciated - its killing me!
This selects from collection controls only that which are of type TextBox.
(the same as control is TextBox or (control as TextBox) != null)
If controls are contained in editQuestionsPanel.Controls:
using System.Linq;
IEnumerable<TextBox> textBoxes = editQuestionsPanel.Controls.OfType<TextBox>();
foreach (TextBox textBox in textBoxes)
{
// do stuff
}
To select all child controls use next extension method:
public static IEnumerable<T> GetChildControls<T>(this Control control) where T : Control
{
var children = control.Controls.OfType<T>();
return children.SelectMany(c => GetChildControls<T>(c)).Concat(children);
}
Using:
IEnumerable<TextBox> textBoxes = editQuestionsPanel.GetChildControls<TextBox>();
When you add controls dynamically, you need to do that on every request - asp.net doesn't do that for you!
Add the controls in the Init or Load phase, then they will get populated with the postback values.
A frequently made mistake: Container.Controls only contains the first level child controls in this container. That is: TextBox1 in PanelA, PanelA in PanelB, you can't get TextBox1 in PanelB.Controls.
My solution is to write an extension method:
public static IEnumerable<Control> AllControls(this Control ctl)
{
List<Control> collection = new List<Control>();
if (ctl.HasControls())
{
foreach (Control c in ctl.Controls)
{
collection.Add(c);
collection = collection.Concat(c.AllControls()).ToList();
}
}
return collection;
}
Now TextBox1 is in PanelB.AllControls(). To filter all controls with type, using PanelB.AllControls().OfType<TextBox>()
If the other answers don't help, try doing your code but add recursivity. Your code would not work if it's editQuestionsPanel => Panel => Textbox
You can do something like this instead:
var questions = from tb in editQuestionsPanel.Controls.OfType<TextBox>()
select tb.Text;
foreach(var question in questions)
{
writeNewQuestionToTblQuestions(question);
}
Try this
int Count = 0;
foreach (Control ctr in Panel1.Controls)
{
if (ctr is TextBox)
Count++;
}
I have a form in which several buttons are added at runtime via a 'for' method
public Form()
{
for (int i = 0 ... )
Button b = new Button()
b.text = (string) i ;
etc..
etc..
}
. now i wish to change the text property of the buttons on a certain event. How can this be accomplished? I have tried a few things but none worked.. since the buttons variables are inside the method , they are not available outside.
Thanks
The variables aren't important (although you could store them in a single List<T> field if it made things easier). The normal way to do this is to look through the Controls collection (recursively, if necessary).
foreach(Control control in someParent.Controls) {
Button btn = control as Button;
if(btn != null) {
btn.Text = "hello world";
// etc
}
}
The above assumes all the buttons were added to the same parent control; if that isn't the case, then walk recursively:
void DoSomething(Control parent) {
foreach(Control control in parent.Controls) {
Button btn = control as Button;
if(btn != null) {
btn.Text = "hello world";
// etc
}
DoSometing(control); // recurse
}
}
You can keep the reference of the button you have created ie you can either have a List with all the dynamic controls in it or if it is only one button, make the button object a class level object so that you can access it anywhere.