What is the difference betweeen the following:
All these dependency properties are defined in Selector class. I often confuse SelectedItem
with SelectedValue
, and SelectedValue
with SelectedValuePath
.
I would like to know the difference between them, and also when do we use them, especially SelectedValue
and SelectedValuePath
. Please explain their use with some simple examples.
This question is related to
wpf
silverlight
xaml
selecteditem
selectedvalue
inspired by this question I have written a blog along with the code snippet here. Below are some of the excerpts from the blog
SelectedItem – Selected Item helps to bind the actual value from the DataSource which will be displayed. This is of type object and we can bind any type derived from object type with this property. Since we will be using the MVVM binding for our combo boxes in that case this is the property which we can use to notify VM that item has been selected.
SelectedValue and SelectedValuePath – These are the two most confusing and misinterpreted properties for combobox. But these properties come to rescue when we want to bind our combobox with the value from already created object. Please check my last scenario in the following list to get a brief idea about the properties.
To answer a little more conceptually:
SelectedValuePath
defines which property (by its name) of the objects bound to the ListBox's ItemsSource
will be used as the item's SelectedValue
.
For example, if your ListBox is bound to a collection of Person
objects, each of which has Name
, Age
, and Gender
properties, SelectedValuePath=Name
will cause the value of the selected Person
's Name
property to be returned in SelectedValue
.
Note that if you override the ListBox's ControlTemplate (or apply a Style) that specifies what property should display, SelectedValuePath
cannot be used.
SelectedItem
, meanwhile, returns the entire Person
object currently selected.
(Here's a further example from MSDN, using TreeView)
Update: As @Joe pointed out, the DisplayMemberPath property is unrelated to the Selected* properties. Its proper description follows:
Note that these values are distinct from DisplayMemberPath
(which is defined on ItemsControl, not Selector), but that property has similar behavior to SelectedValuePath
: in the absence of a style/template, it identifies which property of the object bound to item should be used as its string representation.
Every control that uses Collections to store data have SelectedValue, SelectedItem property. Examples of these controls are ListBox, Dropdown, RadioButtonList, CheckBoxList.
To be more specific if you literally want to retrieve Text of Selected Item then you can write:
ListBox1.SelectedItem.Text;
Your ListBox1 can also return Text using SelectedValue property if value has set to that before. But above is more effective way to get text.
Now, the value is something that is not visible to user but it is used mostly to store in database. We don't insert Text of ListBox1, however we can insert it also, but we used to insert value of selected item. To get value we can use
ListBox1.SelectedValue
SelectedItem
is an object
.
SelectedValue
and SelectedValuePath
are string
s.
for example using the ListBox:
if you say give me listbox1.SelectedValue
it will return the text of the currently selected item.
string value = listbox1.SelectedValue;
if you say give me listbox1.SelectedItem
it will give you the entire object.
ListItem item = listbox1.SelectedItem;
string value = item.value;
Source: Stackoverflow.com