/// <summary>
        /// Returns the zero-based index of the first occurrence of the specified 
        /// <see cref="FormMappingDataRelation"/> in the <see cref="FormMappingDataRelationList"/>.
        /// </summary>
        /// <param name="value">The <see cref="FormMappingDataRelation"/> object 
        /// to locate in the <see cref="FormMappingDataRelationList"/>.
        /// This argument can be a null reference.
        /// </param>    
        /// <returns>
        /// The zero-based index of the first occurrence of <paramref name="value"/> 
        /// in the <see cref="FormMappingDataRelationList"/>, if found; otherwise, -1.
        /// </returns>
        /// <remarks>Please refer to <see cref="ArrayList.IndexOf"/> for details.</remarks>
        public virtual int IndexOf(FormMappingDataRelation value)
        {
            if ((object) value == null)
            {
                for (int i = 0; i < this._count; i++)
                    if ((object) this._array[i] == null)
                        return i;

                return -1;
            }

            for (int i = 0; i < this._count; i++)
                if (value.Equals(this._array[i]))
                    return i;

            return -1;
        }