My question is:
I have this MyAutoCompleteBox, ACBoxDest (it inherits from AutoCompleteBox just with a new event EnterKeyDown but that should be irrelevant to my question) where the ItemsSource is just a list of strings set in the codebehind.
I want to bind the text inside ACBoxDest to always be the same as a public field I have in the codebehind called DestPath.
Currently, when I change the DestPath variable in the codebehind, it doesn't also change the ACBoxDest text in the gui.
The .xaml:
<MyACBox:MyAutoCompleteBox x:Name="ACBoxDest" FilterMode="StartsWith"
Text="{Binding Path=DestPath, Mode=TwoWay}"
ItemContainerStyle="{StaticResource containerStyle}"
Populating="ACBoxDestPopulating"
KeyboardNavigation.TabIndex="1"
EnterKeyDown="EnterKeyHandler"
GotFocus="ACBoxDestFocused"
LostFocus="ACBoxDestUnfocused" />
The codebehind:
public string DestPath {get;set;}
...
private void Initialize()
{
DestPath = _DEFAULT_TARGET_PATH;
if (!ACBoxDest.Text.Equals(DestPath))
MessageBox.Show("ACBoxDest.Text != DestPath");
}
^ For simplicity in explaining debugging, the MessageBox pops up every time. This means that the text inside ACBoxDest is not equal to DestPath, even though they're bound Mode=TwoWay. Does anybody know why this is happening and how I can fix it?
Much appreciated. Thanks.
Your "DestPath" needs to be a property if you want to use it in Binding.
The source of the binding can be any public property, including properties of other controls, common language runtime (CLR) objects, XAML elements, ADO.NET DataSets, XML Fragments, and so forth.
More details at MSDN
As per comments below: In order to update your UI when property gets updates, your VM class needs to implement INotifyPropertyChanged, and in "set" of DestPath you need to raise property changed event. this MSDN link has details and sample code.