Referencing Controls on ASP.Net page

All,

I am populating a section of an ASP.Net page with the following code:

Code:

---

                                if (catList.Count >= 1) {
                                        var CLR = (CategoryLedgerRecord) catList[0];
                                        cboCat1.Text = CLR.CategoryName;
                                        txtAmount1.Text = CLR.Amount.ToString();
                                }
                                if (catList.Count >= 2) {
                                        var CLR = (CategoryLedgerRecord) catList[1];
                                        cboCat2.Text = CLR.CategoryName;
                                        txtAmount2.Text = CLR.Amount.ToString();
                                }
                                if (catList.Count >= 3) {
                                        var CLR = (CategoryLedgerRecord) catList[2];
                                        cboCat3.Text = CLR.CategoryName;
                                        txtAmount3.Text = CLR.Amount.ToString();
                                }
                                if (catList.Count >= 4) {
                                        var CLR = (CategoryLedgerRecord) catList[3];
                                        cboCat4.Text = CLR.CategoryName;
                                        txtAmount4.Text = CLR.Amount.ToString();
                                }
                                if (catList.Count >= 5) {
                                        var CLR = (CategoryLedgerRecord) catList[4];
                                        cboCat5.Text = CLR.CategoryName;
                                        txtAmount5.Text = CLR.Amount.ToString();
                                }

---

I feel like there must be a simpler way to accomplish this. Since ASP.Net doesn't have control arrays like good 'ol VB6 did I'm having difficulty seeing how I could boil this down to a code fragment that might look like the following:

Code:

---

  for (int i=0; i<5; ++i) {
    var CLR = (CategoryLedgerRecord) catList[i];
    Controls["cboCat" + (i+1)].Text = CLR.CategoryName;
    Controls["txtAmount" + (i+1)].Text = CLR.Amount.ToString();
  }

---

The Controls collection only seems to allow you to reference the controls by index #, no overload for specifying a name (which would be nice). I don't see any methods to allow for this. Anyone know of a way to do this?

This isn't a biggie ... I can manage with the first set of code. I just hate having 5 groups of the same code if I could condense it into a loop!

Thanks,

-Max

Then why not establish a Dictionary<string, Control> and iterate the controls by index, asking their id and referencing them?

Code:

---

foreach(Control c in container)
  dict[c.ID] = c;


//set the control with ID BLAH to have text BOO
dict["BLAH"].Text= "BOO";

---

There is also a method called FindControl which may meet your need..

cjard,

Hmm ... yeah, that may just work. Thanks for the idea - I'll give it a try!

-Max

cjard,

The idea you posted pointed me in the right direction. It took a little more work to deal with walking the control tree to get this working properly but now my library is proud owner to a new routine which will be very useful.

Code:

---

/// <summary>
/// Web Version:
///
/// Builds a dictionary containing the references to all controls in the specified controls
/// container so they can be referenced by constructed string names.  This provides the ability
/// to build sections of controls and reference them similarly to the way they could have been
/// with control arrays back in the VB6 days.
/// </summary>
/// <param name="container">Object containing the controls to be discovered.</param>
/// <param name="list">Dictionary into which the references should be placed.</param>
///
public void BuildControlList(System.Web.UI.ControlCollection container, Dictionary<string, System.Web.UI.Control> list) {
        foreach (System.Web.UI.Control c in container) {
                //
                //  If the current control has a set of controls, recurse and scan the collection.
                //
                if (c.Controls.Count > 0)
                        BuildControlList(c.Controls, list);
                //
                //  If this is a leaf node in the controls collection, record its reference in the
                //  dictionary if its ID is not null.
                //
                else {
                        if (c.ID != null)
                                list[c.ID] = c;
                }
        }
}

---

Using that routine in my library now enables me to populate the "control array" I have set up in the following fashion, exactly what I had in mind.

Code:

---

//
// There will be up to 5 categories to list.
//
string key = "";        // Use to build the control names to reference.
       
for (int i = 0; i < catList.Count; ++i) {
        var CLR = (CategoryLedgerRecord) catList[i];
        key = "cboCat" + (i+1).ToString();
        ((DropDownList) cList[key]).Text = CLR.CategoryName;
        key = "txtAmount" + (i+1).ToString();
        ((TextBox) cList[key]).Text = CLR.Amount.ToString();
        key = "txtComment" + (i+1).ToString();
        ((TextBox) cList[key]).Text = CLR.Comments;
}

---

Works perfectly. Thanks for your feedback.

-Max