如何向类类型的命名数组添加值

我有一个用ConfigurationArray类包装的Array Configuration[]，如何使用ConfigurationArray向数组添加值。

public class ConfigurationArray
{
    [DataMember(Name = "configurations")]
    public Configuration[] Configurations { get; set; }
}
public class Configuration
{        
    [DataMember(Name = "configurationType")]
    public string ConfigurationType { get; set; }
    [DataMember(Name = "configurationValue")]
    public string ConfigurationValue { get; set; }
}