wpf TabItem binding IsEnabled - wpf

Question

I would like to bind the IsEnabled property of TabItem to data within my code.
e.g. I have a TabItem defined as follows
<TabItem Name="Tab1" Header="Tab1" IsEnabled="{Binding Path=Tab1Enabled, Mode=TwoWay}">
</TabItem>
And I have defined a data class which inherits from INotifyPropertyChanged as follows
class MyData : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string name)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(name));
}
}
public bool Tab1Enabled
{
get{ return m_tab1Enabled; }
set
{
m_tab1Enabled = value;
OnPropertyChanged("Tab1Enabled");
}
}
}
Then I set the DataContext to my data member.
public partial class MyApp : Window
{
MyData m_myData = new MyData();
MyApp()
{
InitializeComponent();
this.DataContext = m_myData;
}
}
However, when the Tab1Enabled property gets set programatically, the PropertyChanged event is null and so the notification event is not sent.
Thanks in advance.

Answer 1

Im guessing you need to change m_bindinData to the variable you want to bind to (m_myData). I fired up VS2012 and tested your code. Setting m_myData.Tab1Enabled = true; set the tab to enabled and setting m_myData.Tab1Enabled = false; disabled it correctly. Heres what I had.
public partial class MyApp : Window
{
MyData m_myData = new MyData();
MyApp()
{
this.DataContext = m_myData;
InitializeComponent();
m_myData.Tab1Enabled = true;
}
}
class MyData : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string name)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(name));
}
}
public bool Tab1Enabled
{
get { return m_tab1Enabled; }
set
{
m_tab1Enabled = value;
OnPropertyChanged("Tab1Enabled");
}
}
private bool m_tab1Enabled;
}
<TabControl>
<TabItem Name="Tab1" Header="Tab1" IsEnabled="{Binding Path=Tab1Enabled}">
</TabItem>
<TabItem Name="Tab2" Header="Tab2">
</TabItem>
</TabControl>

Answer 2

What about this? Notice the PropertyChangedEventHandler PropertyChanged = PropertyChanged; line in the OnPropertyChanged method.
class MyData : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string name)
{
PropertyChangedEventHandler PropertyChanged = PropertyChanged;
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(name));
}
}
public bool Tab1Enabled
{
get{ return m_tab1Enabled; }
set
{
m_tab1Enabled = value;
OnPropertyChanged("Tab1Enabled");
}
}
}

Answer 3

Your TabItem might not inheriting DataContext of your Window. Try looking into the output window, binding failure error will be there.
As a workaround you can use RelativeSource to travel upto the DataContext of your window and bind with its related property like this -
<TabItem Name="Tab1" Header="Tab1"
IsEnabled="{Binding Path=DataContext.Tab1Enabled,
RelativeSource={RelativeSource Mode=FindAncestor,
AncestorType=Window}, Mode=TwoWay}"/>