将 DataRowCollection 转换为 IEnumable < T >

我想在.NET 3.5中做一些类似的事情。最快的方法是什么？

IEnumerable<DataRow> collection =
TypedDataSet.TypedTableBase<DataRow>.Rows as IEnumerable<DataRow>;

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You can call OfType<DataRow>() on the DataRowCollection.

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最佳答案

Assuming you're using .NET 4.0, which introduces covariance:

// Presumably your table is of some type deriving from TypedTableBase<T>,
// where T is an auto-generated type deriving from DataRow.
IEnumerable<DataRow> collection = myTypedTable;

The table type itself implements IEnumerable<T> where T : DataRow.

Otherwise:

IEnumerable<DataRow> collection = myTypedTable.Cast<DataRow>();

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A simple direct solution is to use the method "Select()" of a System.Data.DataTable object, which produces DataRow[]. From this you can treat as an IEnumerable<DataRow> using Linq like below:

List<MyItem> items = dtItems.Select()
.Select(row => new MyItem(row))
.ToList();

Providing a useful list of objects for each row.

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There is a built in extension method if you include System.Data.DataSetExtensions.dll in to your project that adds a AsEnumerable() method.

IEnumerable<DataRow> collection = TypedDataSet.TypedTableBase<DataRow>.AsEnumerable();