public ColumnStyle this[DataColumn key]
{
get
{
// first look at the column styles hash table, column itself is the key
if (_columnStyles.TryGetValue(key, out var colstyle))
{
return(colstyle);
}
if (_defaultColumnStyles.TryGetValue(key.GetType(), out colstyle))
{
return(colstyle);
}
// second look to the defaultcolumnstyles hash table, key is the type of the column style
System.Type searchstyletype = key.GetColumnStyleType();
if (null == searchstyletype)
{
throw new ApplicationException("Error: Column of type +" + key.GetType() + " returns no associated ColumnStyleType, you have to overload the method GetColumnStyleType.");
}
else
{
// if not successfull yet, we will create a new defaultColumnStyle
colstyle = (ColumnStyle)Activator.CreateInstance(searchstyletype);
colstyle.ParentObject = this;
_defaultColumnStyles.Add(key.GetType(), colstyle);
return(colstyle);
}
}
set
{
bool hadOldValue = _columnStyles.TryGetValue(key, out var oldStyle);
_columnStyles[key] = value ?? throw new ArgumentNullException("value");
value.ParentObject = this;
if (hadOldValue)
{
oldStyle?.Dispose();
}
else
{
AttachKey(key);
}
}
}
