AsInterface Method

Overview

The AsInterface method returns a live, strongly-typed view of a data row as a POCO interface. The returned object is a proxy over the underlying IDataRow, so changes made through the interface are immediately reflected in the row, and changes to the row are visible through the interface.

This overload is a table-level convenience wrapper. It validates the row index, retrieves the row from dataTable.Rows, and then delegates to DataRowExtensions.AsInterface<TInterface>.

Declaration

/// <summary>
/// Gets "live" data row as an interface
/// </summary>
/// <typeparam name="TInterface">POCO interface type</typeparam>
/// <param name="dataTable">Data table</param>
/// <param name="rowIndex">Row index</param>
/// <returns>"Live" data row as an interface</returns>
/// <exception cref="ArgumentOutOfRangeException">Exception is thrown if table does not have row with specified index</exception>
public static TInterface? AsInterface<TInterface>(this IDataTable? dataTable, int rowIndex) where TInterface : class

Namespace and Assembly

Namespace: PocoDataSet.Extensions
Assembly: PocoDataSet.Extensions.dll

Behavior

• If dataTable is null, the method returns default(TInterface).
• If rowIndex is less than 0 or greater than or equal to dataTable.Rows.Count, the method throws ArgumentOutOfRangeException.
• Otherwise, the method retrieves the row at rowIndex and returns DataRowExtensions.AsInterface<TInterface>(dataRow).

Usage Example

Assume there is an interface describing an employment type:

/// <summary>
/// Defines employment type functionality
/// </summary>
internal interface IEmploymentType
{
  int Id { get; set; }
  string Code { get; set; }
  string? Description { get; set; }
}

You can obtain a live POCO interface over an existing row:

// 1. Create an empty data set
IDataSet dataSet = DataSetFactory.CreateDataSet();

// 2. Create an empty data table from POCO interface
IDataTable employmentTypeDataTable = dataSet.AddNewTableFromPocoInterface("EmploymentType", typeof(IEmploymentType));

// 3. Add a row and set values
IDataRow employmentTypeDataRow = employmentTypeDataTable.AddNewRow();
employmentTypeDataRow["Id"] = 1;
employmentTypeDataRow["Code"] = "ET01";
employmentTypeDataRow["Description"] = "Full Time";

// 4. Get data from data row using POCO interface (live projection)
IEmploymentType employmentType = employmentTypeDataTable.AsInterface<IEmploymentType>(0);

// 5. Change data through the interface
employmentType.Code = "ET02";

// 6. Verify that changes propagate to the underlying row
string? updatedCode = employmentTypeDataRow["Code"] as string;

Notes

• AsInterface does not create a copy of the data; it exposes a live projection over the row.
• If you need dataset-level access by table name and row index, see DataSetExtensions.AsInterface.

 

Table of Content POCO DataSet DataTable Extensions Group DataTable Members

 

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Business Process Programming in .Net
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