I have a windows form application that has eight separate progress bars for eight independent tasks (progressBar0 - progressBar7). I want to add these to a list in my code so I can iterate through them.
I declare the list:
List<Control> progressBar = new List<Control>();
Now I iterate through my controls and add those that contain "progressBar" in their name:
foreach (Control control in Controls)
{
if (control.Name.Contains("progressBar")) { progressBar.Add(control); }
}
So far so good. But, I can't set the .Value property:
progressBar[0].Value == 100; <-- this doesn't work
The above won't compile and gives error "Control does not contain a definition for 'Value'". Strangely, if I use intellisense I can drill down into progressBar and find the Value parameter. But for some reason I can't access it programatically and I can't retrieve it from the watch list, either.
I can access the value through AccessibilityObject but is in string format and will be annoying to work with:
progressBar[0].AccessibilityObject.Value = "100%" <-- this works fine
If I access each progressBar directly, everything is fine:
progressBar0.Value = 100; <-- this works fine
What am I doing wrong?
You are using a list of Control, which is the base type for all the control. Value is a property that is specific only to some of the control, in this case, the ProgressBar.
You need to cast it to a ProgressBar:
var progressBars = new List<ProgressBar>();
foreach (var control in Controls)
{
// this ensure the type is a ProgressBar, unlike name, it cant be randomly assigned
if (control is ProgressBar)
{
// a cast is needed here
progressBars.Add(control as ProgressBar);
}
}
progressBars[0].Value = 100;
Related
I have a windows form that just exists to take input from user, for all intents and purposes it is just a label and a corresponding input box (textbox, checkbox, masket textbox etc).
I have programatically placed all the input fields in a TabIndex order that is optimal for cycling through them in a way that fits with their locations (tab down each column of inputs, then to the top of the next column).
The person that I am building this project for has stipulated that only like each textbox to come available one at a time, as the previous one has been filled out. This is a crude way of doing it with no validation, but essentially something like this...
if (String.IsNullOrEmpty(textbox1.Text))
{
textbox2.Enabled = true
}
So this is fine to do with two textboxes in this example, but the form has 28 different inputs on it, so an absurd series of if statements will only be a last resort.
My thoughts has been to put all the inputs in a List, ideally in the same order as is their TabIndexes. I tried to do this using a foreach loop...
List<Control> inputsList = new List<Control>();
public void initialiseControls()
{
//control position to insert control into list at specified index
int cntrlpos = 0;
//for every control in form
foreach (Control cntrl in this.Controls)
{
//not counting labels (not input fields)
if (!(cntrl is Label))
{
//set list position to equal control's TabIndex
cntrlpos = cntrl.TabIndex;
//insert the control into the list at the position reflecting TabIndex
inputsList.Insert(cntrlpos, cntrl); //<---- Error Occurs
//ASK TEXTBOX TO OUTPUT LIST POSITION AS TEST
//foreach (var txtbx in this.Controls.OfType<TextBox>())
//{
// txtbx.Text = Convert.ToString(cntrlpos);
//}
}
}
As soon as the function is called, an exception is thrown stating that "Index must be within the bounds of the list".
When I put a breakpoint into the code, it showed cntrlpos to equal 29, which is more than the 28 total input controls there are on the form.
I don't know where to go from here, if anyone can offer some advice on the code above to place the Controls into the list in the correct order (or point me in the direction of another method to do something like this), then I would really appreciate it.
Thanks,
Mark
To make your list, try this:
List<Control> inputList =
(from Control c in getAllControls(this)
where c.TabStop
orderby c.TabIndex
select c).ToList();
Define the method getAllControls elsewhere in your form class:
IEnumerable<Control> getAllControls(Control parent)
{
foreach (Control control in parent.Controls)
{
yield return control;
foreach (Control descendant in getAllControls(control))
yield return descendant;
}
}
(Taken and modified slightly from Recursive control search with Linq)
This will make it so that you get even nested controls (such as those in panels or groupboxes).
You can't just use the TabIndex as an index into your list, because even stuff like labels have tab indices, which will mess up your indices.
I think you've over complicated it...
Just use Control.GetNextControl:
Retrieves the next control forward or back in the tab order of child
controls.
For example, with just TextBoxes:
private void textBoxes_TextChanged(object sender, EventArgs e)
{
Control ctl = (Control)sender;
if (!String.IsNullOrEmpty(ctl.Text))
{
Control next = this.GetNextControl(ctl, true);
if (next != null)
{
next.Enabled = true;
}
}
}
Obviously you might need a slightly more complicated check for some other types of controls in a different handler, but you'd still just grab the next control to enable using GetNextControl().
I have a C# Form that prints multiple instances of a User Control. Let's say that the form prints 5 instances of the User Control (Please see the link attached). How can I store/save the data inputted in all User Controls? Thanks
Here is the screenshot of the C# Form:
You'll have to store the User Controls when you instantiate them in a List or something.
You could have a class like this:
class SomeUC : UserControl
{
public SomeUC()
{
}
// A public method.
public string GetData()
{
return textBox1.Text;
}
}
Where textBox1 is the Name of a TextBox in your SomeUC
And then inside your main or something.
// Instantiate a List that will hold your UserControls, this has to be outside all methods
List<SomeUC> list = new List<SomeUC>();
// And now when you want to build your UCs
// Instantiate your UserControl
SomeUC uc1 = new SomeUC();
// Store your UserControl in a List or something (Can't help you with that)
list.Add(uc1);
Add as much as you want.
A List is not the only way you can do that, but since you don't know how many UserControls you're going to build beforehand, it makes since to use a List.
And then you can access them from the list by their index.
SomeUC uc1 = list[0];
string data = uc1.GetData();
This is an example of accessing one control (the TextBox) in your SomeUC. For other classes (such as the ComboBox) the interaction is different. Meaning you won't have a Text property in the ComboBox. You'll have to figure out things like that on youself. A little research is what it takes. You can always come back if you couldn't find a solution for something.
You can create a property like this for each item in user control.
public string DG
{
get
{
return txtDG.Text;
}
set
{
txtDG.Text = value;
}
}
Then you can access the control value by using following line in your form.
supposed you have created a usercontrol MyControl and you have placed some object of this control in FlowLayoutPenal (pnlFLP).
To get value from control
string DG = ((MyControl)pnlFLP.Controls[0]).DG;
To set value in control
((MyControl)pnlFLP.Controls[0]).DG = "1";
Try this code for accessing user control in the page
Dim txtName As TextBox = TryCast(UserControlName.FindControl("txtName"), TextBox)
I have a user control (ucMarket) which contains (for the purpose of simplicity) two controls: a ListBox (ucListBox) and a Label (ucLabel). I need to create multiple instances of that user control on the page dynamically (depending on the results from a DataSet), and I add them using a foreach statement and the following:
Panel1.Controls.Add(ucMarket1);
But how do I get access to the ListBox properties like Rows ? The only thing I have found so far is to cast the control as a ListBox:
ListBox listBox1 = (ListBox)ucMarket1.FindControl("ucListBox");
listBox1.Rows = 10;
For the Label part, I guess I can also do something similar:
label1 = (Label)ucMarket1.FindControl("ucLabel");
But then, how do I put that information back into the user control ? Is there a way to work directly with the user control instead of casting ?
Ok a couple of things. from a naming convention point of view, don't call the label & listbox, ucSOMETHING. This is very confusing and not clear from your example whether you're referring to the asp:Label control or some custom userControl you've written. As for accessing your controls.
I'm assuming you are creating and adding a bunch of user controls in the following manner.
for(int i = 0; i < 5; i++)
{
var control = Page.LoadControl("~/Path/To/ucMarket.ascx");
control.Id = "ucMarket" + i;
Panel1.Controls.Add(control);
}
So your best bet is to expose the Listbox on your Control as a public property.
public class ucMarket : UserControl
{
public ListBox TheListBox
{
get { return ucListBox; }
}
}
That way you could access your listbox in the following way.
var ctrl = Panel1.FindControl("ucMarket1") as ucMarket;
ctrl.TheListBox.Rows ;
I have a dynamically created (runtime creation) textbox whose name is available as a string.What i want to do is access this textbox like we do as normal textboxes .Can any one tell me how to cast it as textbox or any other solution
If you know the name of the textbox and its parent controls, you can do like this:
TextBox tb = (TextBox )parent.Controls["name"];
In addition to Iordan's answer, if you don't know exactly where on your form the textbox is, then this extension method should help alot. Note, Form's inherit from Control somewhere down the track too, so you can call it from that, or any control on your form.
public static class ExtensionMethods
{
public static Control FindControl(this Control root, string name)
{
foreach (Control c in root.Controls)
{
// Check this control
if (c.Name == name) return c;
// Check this controls subcontrols
Control tmp = c.FindControl(name);
if (tmp != null) return tmp;
}
return null;
}
}
If this still isn't flexible enough for you, then you can iterate over System.Windows.Forms.Application.OpenForms
Since you seem to have control over the creation process, put a reference to it in a dictionary.
TextBox txt = DynamicCreate(name);
map[name] = txt;
this.Controls.Add(txt);
All you have to do is look it up in your dictionary, instead of loop through all the controls on the form.
TextBox txt = map["name"];
HEllo, I need to dynamically activate fields in a page according to the service that is going to be executed...
Let me explain:
There's a page with all the possible fields and a ListBox with all the selected services to be executed, then when the user selects which service to execute (change a car plate, for example), then I need to activate only the field(s) that the service require... (The realationship between Services and Fields are stored in a database).
public void CheckAll(int pService_Id, Control pPage)
{
foreach (Control control in pPage.Controls)
{
busExecutaServico vExecuta = new busExecutaServico();
if (vExecuta.EnableField(control.ID.ToString(), Convert.ToInt32(listBoxServices.SelectedValue)))
{
switch (control.GetType().ToString())
{
case "TextBox":
TextBox controleText = (TextBox)Page.FindControl(control.ID.ToString());
controleText.Enabled = true;
break;
Note that busExecutaServico is the class which contains the method (EnableField) for checking if the selected item matches any field on the database..
I can't seem to get the control.ID.ToString() to work properly (the ID always comes as NULL)
If anyone can help me solve this, or if there's another way (even if it's completely different from what i'm trying), it would be of great help. thanks
I like to use a recursive function for locating controls by either type or ID.
public Control FindControlRecursive(Control rootControl, string controlId)
{
if (rootControl.ID == controlId)
return rootControl;
foreach (Control control in rootControl.Controls)
{
Control foundControl = FindControlRecursive(control, controlId);
if (foundControl != null)
{
return foundControl;
}
}
return null;
}
public Control FindControlRecursive(Control rootControl, Type type)
{
if (rootControl.GetType().Equals(type))
return rootControl;
foreach (Control control in rootControl.Controls)
{
Control foundControl = FindControlRecursive(control, type);
if (foundControl != null)
{
return foundControl;
}
}
return null;
}
You can adapt these to first return a collection of controls, then process them later. Might be easier to keep track of what's happening.
I learned this technique here: http://www.west-wind.com/Weblog/posts/5127.aspx
Be aware that FindControl only searches the current naming container so Page.FindControl will only find controls that are added directly to Page. For example, if you had a repeater control that had the controls you were looking for and it was added to Page, you could find your repeater control via Page.FindControl but it wouldn't find child controls within your repeater, you'd have to recursively perform the FindControl on all container controls in the page.
This might seem a bit strange but it allows you to have controls with the same ID existing on the same page. For example, if you had 10 instances of a user control with textboxes within them called "MyName", you'd really want them to not being over-writing each other's 'MyName' fields!
Your code will come across a null for an ID unless every control has been given an ID.
Also why use:-
TextBox controleText = (TextBox)Page.FindControl(control.ID.ToString());
at all instead of:-
TextBox controleText = (TextBox)control;
and indeed since you only want to change the Enabled property consider:-
((WebControl)control).Enabled = False;
That I suspect will eliminate many case statements.
In your code you don't need to search any control - you already have it in 'control' variable. You even don't need to cast it to TextBox, just to a WebControl, just do this:
...
if (vExecuta.EnableField(control.ID.ToString(), Convert.ToInt32(listBoxServices.SelectedValue)))
((WebControl)control).Enabled = true;
P.S. control.ID is already string, so you should remove any ID.ToString() also.