Question

When i do something like this:

public static void BindData<T>(this System.Windows.Forms.Control.ControlCollection controls, T bind)
    {
        foreach (Control control in controls)
        {
            if (control.GetType() == typeof(System.Windows.Forms.TextBox) || control.GetType().IsSubclassOf(typeof(System.Windows.Forms.TextBox)))
            {
                UtilityBindData(control, bind);
            }
            else
            {
                if (control.Controls.Count == 0)
                {
                    UtilityBindData(control, bind);
                }
                else
                {
                    control.Controls.BindData(bind);
                }
            }
        }
    }

    private static void UtilityBindData<T>(Control control, T bind)
    {
        Type type = control.GetType();

        PropertyInfo propertyInfo = type.GetProperty("BindingProperty");
        if (propertyInfo == null)
            propertyInfo = type.GetProperty("Tag");

// rest of the code....

where controls is System.Windows.Forms.Control.ControlCollection and among controls on the form that is passed as a parameter to this piece of code there are NumericUpDowns, i cant find them in the controls collection (controls=myForm.Controls), but there are controls of other types(updownbutton, updownedit). The problem is that i want to get NumericUpDown’s Tag property and just cant get it when using that recursive method of checking form controls.

Answer 1

The Tag property is defined by the Control class.

Therefore, you don’t need reflection at all; you can simply write

object tag = control.Tag;

Your code isn’t working because the control’s actual type (eg, NumericUpDown) doesn’t define a separate Tag property, and GetProperty doesn’t search base class properties.

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By the way, in your first if statemeant, you can simply write

if (control is TextBox)