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Databinding for CheckState

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Jan asked on 09 Feb 2010, 09:52 AM

I started with the example with the Leages and Division (as example for data binding from the Demo) and added a tristate checkbox to the treeview and a "bool?" in each class. Initially all items are set to "true".

    
            public League(string name) 
        
            { 
        
              _name = name; 
        
              _divisions = new List<Division>(); 
        
              _selected = true; 
        
            } 
        
            string _name; 
        
            bool? _selected; 
        
            public string Name { get { return _name; } } 
        
            public bool? Selected { get { return _selected; } }

As described here I added the CheckStateConverter class which also handles the Indeterminate state.

    
            public class CheckStateConverter : IValueConverter 
        
            { 
        
              public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 
        
              { 
        
                bool? result = (bool?)value; 
        
                ToggleState returnValue = ToggleState.Indeterminate; 
        
                if (result == true) 
        
                  returnValue = ToggleState.On; 
        
                else 
        
                { 
        
                  if (result == false) 
        
                    returnValue = ToggleState.Off; 
        
                } 
        
                return returnValue; 
        
              } 
        
            //....

The data binding works fine, but the thing I can't understand: If I expand "League A" and "Division A" and uncheck "Team I", "League A" and "Division A" also switch to "unchecked" instead of "indeterminate". If I uncheck "League A" and check it again the whole tree behaves correctly. What is wrong in my example?

Thanks in advance!
Jan

Databinding for CheckState

5 Answers, 1 is accepted