Passing int array as parameter in web user control

Great snippet @mathieu. I needed to use this for converting longs, but rather than making a LongArrayConverter, I wrote up a version that uses Generics.

public class ArrayConverter<T> : TypeConverter
{
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
return sourceType == typeof(string);
}

public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
string val = value as string;
if (string.IsNullOrEmpty(val))
return new T[0];

string[] vals = val.Split(',');
List<T> items = new List<T>();
Type type = typeof(T);
foreach (string s in vals)
{
T item = (T)Convert.ChangeType(s, type);
items.Add(item);
}
return items.ToArray();
}
}

This version should work with any type that is convertible from string.

[TypeConverter(typeof(ArrayConverter<int>))]
public int[] Ints { get; set; }

[TypeConverter(typeof(ArrayConverter<long>))]
public long[] Longs { get; set; }

[TypeConverter(typeof(ArrayConverter<DateTime))]
public DateTime[] DateTimes { get; set; }

If you use DataBinding on one of the parent Controls, you can use a DataBinding Expression:

<uc1:mycontrol runat="server" myintarray="<%# new [] {1, 2, 3} %>" />


With a custom expression builder, you can do something similar. The expression builder:


[ExpressionPrefix("Code")]
public class CodeExpressionBuilder : ExpressionBuilder
{
public override CodeExpression GetCodeExpression(System.Web.UI.BoundPropertyEntry entry, object parsedData, ExpressionBuilderContext context)
{
return new CodeSnippetExpression(entry.Expression.Trim());
}
}

Usage:

<uc1:mycontrol runat="server" myintarray="<%$ Code: new [] {1, 2, 3} %>" />