Data-Mapped columns

Data-mapped columns contain keys instead of actual values. For example, the column may contain an integer that represents a country ID, but users should see and edit the corresponding country name instead.

This scenario requires a little more than two lines of code:

C#	Copy Code
// build key-value dictionary var dct = new Dictionary<int, string>(); foreach (var country in GetCountryNames()) { dct[dct.Count] = country; } // assign dictionary to column var c = _flexEdit.Columns["CountryID"]; c.ValueConverter = new ColumnValueConverter(dct); c.HorizontalAlignment = HorizontalAlignment.Left;

Copy Code

// build key-value dictionary 
var dct = new Dictionary<int, string>(); 
foreach (var country in GetCountryNames()) 
{ 
  dct[dct.Count] = country; 
} 
 
// assign dictionary to column 
var c = _flexEdit.Columns["CountryID"]; 
c.ValueConverter = new ColumnValueConverter(dct); 
c.HorizontalAlignment = HorizontalAlignment.Left;

The code starts by building a dictionary that maps country ID values (integers) to country names (strings).

It then uses the dictionary to build a ColumnValueConverter and assigns the converter to the column's ValueConverter property as in the previous examples.

The user will be able to select any countries present in the dictionary, and will not be able to enter any unmapped values.

Finally, the code sets the column alignment to left. Since the column actually contains integer values, it is aligned to the right by default. But since we are now displaying names, left alignment is a better choice here.

The image below shows the appearance of the editor while selecting a value from a list. Notice how the editor supports smart auto-completion, so as the user types “Ger,” the dropdown automatically selects the only valid option “Germany” (and not “Guatemala,” then “Eritrea,” then “Romania”).

WPF Reference

ColumnValueConverter Class

ValueConverter Property

Silverlight Reference

ColumnValueConverter Class

ValueConverter Property