Find Item By Content and Find Item By Value

[Rory]

Hello,
I was wondering what is the best way to see whether a RadComboBoxItem exists inside a RadComboBox?

I can get the ComboBox.Items collection but I'm not seeing a method for determining whether an item that we are looking for is already in the list.
Thanks.

[Valeri Hristov]

Hi Rory,

You could use a simple Linq expression to check whether there is a certain RadComboBoxItem (or other object) present in the RadComboBox.Items collection:

using System.Linq;
...
bool exists = combo.Items.Any(item => (item as RadComboBoxItem).Content == "value");
if (exists)
{
...
}

Greetings,
Valeri Hristov
the Telerik team

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[Chase]

How are you doing a Linq query against an ItemCollection collection type?  I literally just pasted this line of code into my sandbox test app to see if this works (and it does not as you can see below, unless there is more than one RadComboBox?).

Here's the error as proof.   How are you making this work?

[Martin Ivanov]

You can cast the Items collection to the corresponding item type. For example:

comboBox.Items.OfType<RadComboBoxItem>().Any(x => x.Content.Equals("value"));

Note that if the ItemsSource is populated with a collection of custom objects, the Items collection will contain these elements. In that case, you can use the corresponding data type in the OfType<T> method, and the data model property in the conditional statement.

comboBox.Items.OfType<MyItemInfo>().Any(x => x.MyContentProperty.Equals("value"));

 

[Labcorp]

Using a similar example, How do you retrieve the index  of something that exists

[Kalin]

Hello Labcorp,

In order to find the index of the desired Item you could use again a simple Linq expression. Please check the following code snippet:

var item = this.Combo.Items.FirstOrDefault(i => (i as RadComboBoxItem).Content.ToString() == "value");
if (item != null)
{
    int indexOfItem = this.Combo.Items.IndexOf(item);
}

Hope this helps.

Regards,
Kalin
Telerik