DataTables and custom types

Question

I created a class called CustomData which uses another one called CustomOptions as one of its fields. I want to use the CustomData in a DataTable as values. Here's a short overview (simplified, the fields are private and the accessors public, mostly readonly and the set is done by custom methods);

enum CustomDataOptionType
{
 // Some values, not important
}

class CustomOptions
{
 public CustomDataOptionType type { get; }
 public Dictionary<string, string> values { get; }
 // Some Methods to set the values
}

class CustomData
{
 public CustomOptions options { get; }
 // Some Methods to set the options
}

So, in the "actual" class that uses the ones above, I create a DataTable, using columns that are typeof(CustomData).

But when I try to access the columns, e.g. by

DataRow Row = data.Rows.Find("bla");
Row["colmn1"].options; // Not possible

Why can't I access the options-field?

Answer 1

You need to cast it into the type CustomData.

((CustomData)Row["colmn1"]).options

Answer 2

Because the Row["column1"] returns "object". You need cast the value to your type:

((CustomData)Row["column1"]).Options.

EDIT: If you want handle the NULL values, you should use this:

CustomData data = Row["column1"] as CustomData;
if ( null != data ) {
    // do what you want
}

Or you can use a extension methods for simplify it:

public static DataRowExtensionsMethods {
    public static void ForNotNull<T>( this DataRow row, string columnName, Action<T> action ) {
        object rowValue = row[columnName];
        if ( rowValue is T ) {
            action( (T)rowValue );
        }
    }
}
// somewhere else
Row.ForNotNull<CustomData>( "column1", cutomData => this.textBox1.Text = customData.Username );