Add value to ComboBox

In winform, unlike in Web, ComboBox (winform), dropdownlist (Web), and item

 

Different, the value of item cannot be directly added to winform, but the value of item can be added to web.

 

Write a ComboBox here to add the value.

 

Class dropdownlist: system. Windows. Forms. ComboBox
{
Private bool _ useitemvalue;

[System. componentmodel. Description ("whether to enable value. If so, call the bindvalue method after binding data")]
[System. componentmodel. Category ("data")]
[System. componentmodel. browsable (true)]
[System. componentmodel. defaultvalue (false)]
Public bool useitemvalue
{
Get {return _ useitemvalue ;}
Set {_ useitemvalue = value ;}
}

/// <Summary>
/// Bind the value to the item
/// </Summary>
/// <Param name = "Sep"> delimiter </param>
Public void bindvalue (char SEP)
{
# Region bind the value to the item
If (_ useitemvalue)
{
List <keyvaluepair <string, Object> dit = new list <keyvaluepair <string, Object> ();
Foreach (Object OBJ in this. Items)
{
String text = "";
If (obj is system. Data. datarowview)
{
TEXT = (system. Data. datarowview) OBJ). Row. itemarray [0]. tostring ();
}
Else
{
TEXT = obj. tostring ();
}
String [] value = text. Split (SEP );
Try
{
Dit. Add (New keyvaluepair <string, Object> (value [0], value [1]);
}
Catch
{
Dit. Add (New keyvaluepair <string, Object> (text ,""));
}
}
This. datasource = dit;
This. displaymember = "key ";
This. valuemember = "value ";
}
# Endregion
}
}

 

After successful generation, set the value of useitemvalue in "data" to true.

 

And call the bindvalue method.