Selected TextBlocks value in Listbox wpf

If the list box is multi-selectable, you can use the property SelectedItems, otherwise you can use the property SelectedItem, SelectedValue or SelectedIndex. You will come to the item reference, which can actually be of any type, not just string, so the compile-time type of the returned object is System.Object; you can check up its runtime type, but from your design your know what is it. It should be either TextBlock or some UI elements with to child text blocks (I don't know you exact design as you did not share any code, but you should know it). This way, you come to the instance of TextBlock, so you can extract the text using the property TextBlock.Text. That's all.

Please see:
http://msdn.microsoft.com/en-us/library/system.windows.controls.listbox.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.selector.selectedindex.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.selector.selecteditem.aspx[^]
http://msdn.microsoft.com/en-us/library/system.windows.controls.listbox.selecteditems.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.controls.primitives.selector.selectedvalue.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.controls.textblock.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.controls.textblock.text.aspx[^].

—SA