Пример #1
0
        private bool VerifyEqual(object knownValue, Type knownType, object itemValue, DynamicValueConverter converter)
        {
            object tempValue = knownValue;
 
            if (knownType != null && itemValue != null)
            { 
                Type itemType = itemValue.GetType(); 

                // determine if selectedValue is comparable to itemValue, convert if necessary 
                // using a DefaultValueConverter
                if (!knownType.IsAssignableFrom(itemType))
                {
                    tempValue = converter.Convert(knownValue, itemType); 
                    if (tempValue == DependencyProperty.UnsetValue)
                    { 
                        // can't convert, keep original value for the following object comparison 
                        tempValue = knownValue;
                    } 
                }
            }

            return Object.Equals(tempValue, itemValue); 
        }
Пример #2
0
        private object FindItemWithValue(object value)
        {
            if (!HasItems)
                return DependencyProperty.UnsetValue; 

            // use a representative item to determine which kind of binding to use (XML vs. CLR) 
            BindingExpression bindingExpr = PrepareItemValueBinding(Items.GetRepresentativeItem()); 

            if (bindingExpr == null) 
                return DependencyProperty.UnsetValue;   // no suitable item found

            // optimize for case where there is no SelectedValuePath (meaning
            // that the value of the item is the item itself, or the InnerText 
            // of the item)
            if (string.IsNullOrEmpty(SelectedValuePath)) 
            { 
                // when there's no SelectedValuePath, the binding's Path
                // is either empty (CLR) or "/InnerText" (XML) 
                string path = bindingExpr.ParentBinding.Path.Path;
                Debug.Assert(String.IsNullOrEmpty(path) || path == "/InnerText");
                if (string.IsNullOrEmpty(path))
                { 
                    // CLR - item is its own selected value
                    if (Items.Contains(value)) 
                        return value; 
                    else
                        return DependencyProperty.UnsetValue; 
                }
                else
                {
                    // XML - use the InnerText as the selected value 
                    return FindXmlNodeWithInnerText(value);
                } 
            } 

            Type selectedType = (value != null) ?  value.GetType() : null; 
            object selectedValue = value;
            DynamicValueConverter converter = new DynamicValueConverter(false);

            foreach (object current in Items) 
            {
                bindingExpr.Activate(current); 
                object itemValue = bindingExpr.Value; 
                if (VerifyEqual(value, selectedType, itemValue, converter))
                { 
                    bindingExpr.Deactivate();
                    return current;
                }
            } 
            bindingExpr.Deactivate();
 
            return DependencyProperty.UnsetValue; 
        }