CODEWITHSUNDEEP
c#asp.netwebformsfindcontrol
Eric Herlitz
Eric Herlitz

Reputation: 26307

Equivalent to jQuery closest() in ASP.NET Web Forms

Im trying to figure out a way to build a somewhat clever version of the jQuery closest method in C#. Im using a generic method to find the desired control and then index the control chain

public static T FindControlRecursive<T>(Control control, string controlID, out List<Control> controlChain) where T : Control
{
    controlChain = new List<Control>();

    // Find the control.
    if (control != null)
    {
        Control foundControl = control.FindControl(controlID);

        if (foundControl != null)
        {
            // Add the control to the list
            controlChain.Add(foundControl);    

            // Return the Control
            return foundControl as T;
        }
        // Continue the search
        foreach (Control c in control.Controls)
        {
            foundControl = FindControlRecursive<T>(c, controlID);

            // Add the control to the list
            controlChain.Add(foundControl);

            if (foundControl != null)
            {
                // Return the Control
                return foundControl as T;
            }
        }
    }
    return null;
}

To Call it

List<Control> controlChain;
var myControl = FindControls.FindControlRecursive<TextBox>(form, "theTextboxId"), out controlChain);

To find the closest element of id or type

// Reverse the list so we search from the "myControl" and "up"
controlChain.Reverse();
// To find by id
var closestById = controlChain.Where(x => x.ID.Equals("desiredControlId")).FirstOrDefault();

// To find by type
var closestByType = controlChain.Where(x => x.GetType().Equals(typeof(RadioButton))).FirstOrDefault();

Would this be a good approach or are there any other cool solutions out there creating this? Whats your consideration?

Thanks!

Upvotes: 1

Views: 1001

Answers (1)

Magnus
Magnus

Reputation: 46967

Maybe something like this

public static IEnumerable<Control> GetControlHierarchy(Control parent, string controlID)
{
    foreach (Control ctrl in parent.Controls)
    {
        if (ctrl.ID == controlID)
            yield return ctrl;
        else
        {
            var result = GetControlHierarchy(ctrl, controlID);
            if (result != null)
                yield return ctrl;
        }
        yield return null;
    }
}

Upvotes: 1

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