/// <summary>
/// Get the value to display through reflection on <paramref name="item"/> using property <see cref="DisplayMemberPath"/>
/// </summary>
/// <param name="item">Item to get value from.</param>
/// <returns>Value of the property <see cref="DisplayMemberPath"/> if not <c>null</c>; otherwise ToString()</returns>
/// <exception cref="ArgumentException">If no property with name <see cref="DisplayMemberPath"/> is found</exception>
protected virtual string GetDisplayMember(object item)
{
if (DisplayMemberFunc != null)
{
return(DisplayMemberFunc(item));
}
if (item == null)
{
return(string.Empty);
}
if (IsPrimitive(item) || string.IsNullOrEmpty(DisplayMemberPath))
{
return(item.ToString());
}
// Find the property by walking the display member path to find any nested properties
var propertyPathParts = DisplayMemberPath.Split('.');
object propertyValue = item;
foreach (var propertyPathPart in propertyPathParts)
{
var propInfo = propertyValue.GetType().GetTypeInfo().GetDeclaredProperty(propertyPathPart);
if (propInfo == null)
{
throw new ArgumentException($"No property '{propertyPathPart}' was found on '{propertyValue.GetType().FullName}'");
}
propertyValue = propInfo.GetValue(propertyValue);
}
if (propertyValue == null)
{
throw new ArgumentException($"No property '{DisplayMemberPath}' was found on '{item.GetType().FullName}'");
}
return(propertyValue as string);
}
private void CheckSelectedPropertyInfo()
{
object firstItem = null;
foreach (var item in ItemsSource)
{
firstItem = item;
break;
}
if (firstItem == null)
{
return;
}
if (DisplayMemberPath.IsNullOrEmpty())
{
throw new Exception("Property 'DisplayMemberPath' can not be null or empty.");
}
if (SelectedMemberPath.IsNullOrEmpty())
{
throw new Exception("Property 'SelectedMemberPath' can not be null.");
}
_selectedPropertyInfo = firstItem.GetType().GetProperty(SelectedMemberPath);
_displayPropertyInfo = firstItem.GetType().GetProperty(DisplayMemberPath);
if (_displayPropertyInfo == null)
{
throw new Exception("'" + DisplayMemberPath + "' does not existed.");
}
if (_selectedPropertyInfo == null || _selectedPropertyInfo.PropertyType != typeof(bool))
{
throw new Exception("'" + SelectedMemberPath + "' does not existed , or is not 'bool' type.");
}
}
