Inherit from DropDownList and his ListItems

Question

User-1379029596 posted

 Hello!

I just try to extend the asp DropDownList and his ListItems, because the "Value" property isn't enough for me and I need a second "Value" property for e.g. "Value2".

Here is the code for my inherited DropDownList:

 

namespace My_WebControls
{
       [DefaultProperty("Text")]
       [ToolboxData("<{0}:my_DropDownList runat=server></{0}:my_DropDownList>")]
       public class my_DropDownList : DropDownList
       {

       }
}

 

Here are my questions: 

1. How can I create my own ListItems for my DropDownList with a new property for e.g. "Value2" ?

2. When I can extend the ListItems with the new Property "Value2",  how can I create a property for my DropDownList like "SelectedValue2"?

 

Thank you in advance and sry for me bad english! [;)]

Best Regards

DellaRocco

 

Answer 1

User-2106054853 posted

Hi,

It's not easy to implement since ListItem is a sealed class.

If you need a "SelectedValue2" why not use some tricks? You can use a symbol to separate two values and assign the entire string to ListItem.Value, such as:

"Value1_Value2"

You know the "_" will not appear in the data so it's safe to use it. In other cases where "_" might occur in your data you can use other weird alien word to separate real data.

By spliting the string you can get both values.

Answer 2

User-1379029596 posted

Thank your for your answer!

When I look at it.....it's so simple! Shame on me! [;)]

Best Regards

DellaRocco