C＃在RadComboboxItem上使用.Contains搜索字符串

Question

Currently I am trying to create some cascading combo boxes. The program has 4 RadComboBoxes (telerik control). I place the default data into dropdowns and all is good. I can multi-select from these boxes. When I select values from box 1 it should filter the choices in box 2.

protected void rcbProgram_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
    {            
        rcbPartGroup.DataSource = db.tblPartStyles.Where(c=>rcbProgram.CheckedItems.Contains(c.Program)).Select(c => c.PartGroup);
        rcbPartGroup.DataBind();

    }

I want rcbPartGroup's datasource to be the PartGroup field of tblPartStyles where the Program field is in rcbProgram's checked list. This would work fine, but rcbProgram.CheckedList is a List and will not compare with a string (The program field value). I am still having a difficult time wrapping my head around how this would work if both are strings, but now I have 2 different types that I cannot manage to convert. Anyone have anything they know that I can do to make this work?

Answer 1

I was a bit confused by the lambda statement at first. I did a simple fix. I created a list of strings and ran through a foreach to add the values in the CheckedItems list. I then used the string list to perform the lambda filter.

 protected void rcbProgram_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
    {
        **List<String> _selectedItems = new List<String>();
        foreach (RadComboBoxItem i in rcbProgram.CheckedItems)
        {
            _selectedItems.Add(i.Value);
        }**


        rcbPartGroup.DataSource = db.tblPartStyles.Where(c=>_selectedItems.Contains(c.Program)).Select(c => c.PartGroup).Distinct();
        rcbPartGroup.DataBind();

    }