Knowing Your DataContext
Every control in WPF has a data context, the control can access properties from your data context
Using Snoop
you can select an object on your application and see the Data Context tab to see where your control is bound
In this example we are bound to the application view model object in C#. We can then using data binding to access the currentUserName property of the application view model
Binding – Regular Property
The RadButton property takes the below values
So we have a converter in our user control resources which converts booleans into visibile not
We then use the converter on the RadButton, which will convert our boolean (canAddToWhitelist) into one of the above values using our converter
<UserControl.Resources>
<BooleanToVisibilityConverter x:Key=
"boolToVis"
/>
<UserControl.Resources>
<telerik:RadButton Content=
"Allow"
Visibility=
"{Binding canAddToWhitelist, Converter={StaticResource boolToVis}}"
/>
<Window.Resources>
<sys:String x:Key=
"strHelloWorld"
>Hello, world!</sys:String>
</Window.Resources>
<StackPanel Margin=
"10"
>
<TextBlock Text=
"{StaticResource strHelloWorld}"
/>
</StackPanel>
public
ICommand runDataLoadCommand
get
{
return
new
DelegatingCommand(ShowConfirmRunJob); }
public
void
ShowConfirmRunJob()
Note: this uses the
DelegatingCommand
class
Command Binding With Relative Source and the 2nd Type of Ancestor in Heirarchy
The following code will create a button
<Button Name=
"btnExportUnmatchedReceipts"
Command=
"{Binding ExportToExcelCommand}"
CommandParameter=
"{Binding ElementName=grvSearchList}"
DataContext=
"{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type telerik:RadTabControl},AncestorLevel=2},Path=DataContext}"
/>
This section
"{RelativeSource FindAncestor, AncestorType={x:Type telerik:RadTabControl},AncestorLevel=2}"
Will set the data context of the button to 2 tabcontrols above in the heirarchy
In Snoop this looks like this
So we are getting the DataContext of the top radControl because we have said Ancestor level 2, so it will skip the SearchTabControl
The data content of the radTabControl is the ApplicationViewModel so we can access any of the properties on this data context
So looking at this binding again
<Button Name=
"btnExportUnmatchedReceipts"
Command=
"{Binding ExportToExcelCommand}"
CommandParameter=
"{Binding ElementName=grvSearchList}"
DataContext=
"{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type telerik:RadTabControl},AncestorLevel=2},Path=DataContext}"
/>
And given that the context is the application view model, we can access the property ExportToExcelCommand
So this part of the code works because there is a property called ExportToExcelCommand to bind to
public
ICommand ExportToExcelCommand
get
{
return
new
DelegatingCommand(exportUnmatchedReceipts); }
private
void
exportUnmatchedReceipts(
object
grid)
GridExporter.exportGrid(grid
as
RadGridView);
<Button Name=
"btnExportUnmatchedReceipts"
Command=
"{Binding ExportToExcelCommand}"
CommandParameter=
"{Binding ElementName=grvSearchList}"
DataContext=
"{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type telerik:RadTabControl},AncestorLevel=2},Path=DataContext}"
/>
Create a Button
The data context of the button should be the same as the main tab control (application view model)
We say when the button is clicked it will hit the ExportToExcelCommand on the Application View Model
And we will pass a RadGridView as the parameter using Command Parameter
MSDN Data Binding
Data Binding Overview
Privacy & Cookies: This site uses cookies. By continuing to use this website, you agree to their use.
To find out more, including how to control cookies, see here:
Cookie Policy
