System.Data.Common.DataColumnMappingCollection.IndexOf C# (CSharp) Method

        public int IndexOf(object value)
        {
            if (null != value)
            {
                ValidateType(value);
                for (int i = 0; i < Count; ++i)
                {
                    if (_items[i] == value)
                    {
                        return i;
                    }
                }
            }
            return -1;
        }

        [EditorBrowsableAttribute(EditorBrowsableState.Advanced)]   // MDAC 69508
        static public DataColumnMapping GetColumnMappingBySchemaAction(DataColumnMappingCollection columnMappings, string sourceColumn, MissingMappingAction mappingAction)
        {
            if (null != columnMappings)
            {
                int index = columnMappings.IndexOf(sourceColumn);
                if (-1 != index)
                {
#if DEBUG
                    if (AdapterSwitches.DataSchema.TraceInfo)
                    {
                        Debug.WriteLine("mapping match on SourceColumn \"" + sourceColumn + "\"");
                    }
#endif
                    return(columnMappings.items[index]);
                }
            }
            if (ADP.IsEmpty(sourceColumn))
            {
                throw ADP.InvalidSourceColumn("sourceColumn");
            }
            switch (mappingAction)
            {
            case MissingMappingAction.Passthrough:
#if DEBUG
                if (AdapterSwitches.DataSchema.TraceInfo)
                {
                    Debug.WriteLine("mapping passthrough of SourceColumn \"" + sourceColumn + "\"");
                }
#endif
                return(new DataColumnMapping(sourceColumn, sourceColumn));

            case MissingMappingAction.Ignore:
#if DEBUG
                if (AdapterSwitches.DataSchema.TraceWarning)
                {
                    Debug.WriteLine("mapping filter of SourceColumn \"" + sourceColumn + "\"");
                }
#endif
                return(null);

            case MissingMappingAction.Error:
#if DEBUG
                if (AdapterSwitches.DataSchema.TraceError)
                {
                    Debug.WriteLine("mapping error on SourceColumn \"" + sourceColumn + "\"");
                }
#endif
                throw ADP.MissingColumnMapping(sourceColumn);
            }
            throw ADP.InvalidMissingMappingAction(mappingAction);
        }