DataTableExtensions.cs

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using System.Collections.Generic;
using System.Globalization;
 
namespace System.Data;
 
public static class DataTableExtensions
{
    public static EnumerableRowCollection<DataRow> AsEnumerable(this DataTable source)
    {
        DataSetUtil.CheckArgumentNull(source, "source");
        return new EnumerableRowCollection<DataRow>(source);
    }
 
    public static DataTable CopyToDataTable<T>(this IEnumerable<T> source) where T : DataRow
    {
        DataSetUtil.CheckArgumentNull(source, "source");
        return LoadTableFromEnumerable(source, null, null, null);
    }
 
    public static void CopyToDataTable<T>(this IEnumerable<T> source, DataTable table, LoadOption options) where T : DataRow
    {
        DataSetUtil.CheckArgumentNull(source, "source");
        DataSetUtil.CheckArgumentNull(table, "table");
        LoadTableFromEnumerable(source, table, options, null);
    }
 
    public static void CopyToDataTable<T>(this IEnumerable<T> source, DataTable table, LoadOption options, FillErrorEventHandler? errorHandler) where T : DataRow
    {
        DataSetUtil.CheckArgumentNull(source, "source");
        DataSetUtil.CheckArgumentNull(table, "table");
        LoadTableFromEnumerable(source, table, options, errorHandler);
    }
 
    private static DataTable LoadTableFromEnumerable<T>(IEnumerable<T> source, DataTable table, LoadOption? options, FillErrorEventHandler errorHandler) where T : DataRow
    {
        if (options.HasValue)
        {
            LoadOption value = options.Value;
            if ((uint)(value - 1) > 2u)
            {
                throw DataSetUtil.InvalidLoadOption(options.Value);
            }
        }
        using (IEnumerator<T> enumerator = source.GetEnumerator())
        {
            if (!enumerator.MoveNext())
            {
                return table ?? throw DataSetUtil.InvalidOperation(System.SR.DataSetLinq_EmptyDataRowSource);
            }
            if (table == null)
            {
                DataRow current = enumerator.Current;
                if (current == null)
                {
                    throw DataSetUtil.InvalidOperation(System.SR.DataSetLinq_NullDataRow);
                }
                table = new DataTable
                {
                    Locale = CultureInfo.CurrentCulture
                };
                foreach (DataColumn column in current.Table.Columns)
                {
                    table.Columns.Add(column.ColumnName, column.DataType);
                }
            }
            table.BeginLoadData();
            try
            {
                do
                {
                    DataRow current = enumerator.Current;
                    if (current == null)
                    {
                        continue;
                    }
                    object[] values = null;
                    try
                    {
                        switch (current.RowState)
                        {
                        case DataRowState.Detached:
                            if (!current.HasVersion(DataRowVersion.Proposed))
                            {
                                throw DataSetUtil.InvalidOperation(System.SR.DataSetLinq_CannotLoadDetachedRow);
                            }
                            goto case DataRowState.Unchanged;
                        case DataRowState.Unchanged:
                        case DataRowState.Added:
                        case DataRowState.Modified:
                            values = current.ItemArray;
                            if (options.HasValue)
                            {
                                table.LoadDataRow(values, options.Value);
                            }
                            else
                            {
                                table.LoadDataRow(values, fAcceptChanges: true);
                            }
                            break;
                        case DataRowState.Deleted:
                            throw DataSetUtil.InvalidOperation(System.SR.DataSetLinq_CannotLoadDeletedRow);
                        default:
                            throw DataSetUtil.InvalidDataRowState(current.RowState);
                        }
                    }
                    catch (Exception ex)
                    {
                        if (!DataSetUtil.IsCatchableExceptionType(ex))
                        {
                            throw;
                        }
                        FillErrorEventArgs fillErrorEventArgs = null;
                        if (errorHandler != null)
                        {
                            fillErrorEventArgs = new FillErrorEventArgs(table, values)
                            {
                                Errors = ex
                            };
                            errorHandler(enumerator, fillErrorEventArgs);
                        }
                        if (fillErrorEventArgs == null)
                        {
                            throw;
                        }
                        if (!fillErrorEventArgs.Continue)
                        {
                            if ((fillErrorEventArgs.Errors ?? ex) == ex)
                            {
                                throw;
                            }
                            throw fillErrorEventArgs.Errors;
                        }
                    }
                }
                while (enumerator.MoveNext());
            }
            finally
            {
                table.EndLoadData();
            }
        }
        return table;
    }
 
    public static DataView AsDataView(this DataTable table)
    {
        DataSetUtil.CheckArgumentNull(table, "table");
        return new LinqDataView(table, null);
    }
 
    public static DataView AsDataView<T>(this EnumerableRowCollection<T> source) where T : DataRow
    {
        DataSetUtil.CheckArgumentNull(source, "source");
        return source.GetLinqDataView();
    }
}