ADO.NET:检查字段名称是否存在于IDATARATION

尝试{…}捕获{…} 布洛克,但这是某种 . 一些替代品?

/// <summary>
/// Returns column value from IDataRecord only if field_name exists.
/// </summary>
public static Tresult ValueIfExists<Tresult>(this IDataRecord record, string field_name)
{
    try { return record.Value<Tresult>(record.GetOrdinal(field_name)); }
    catch { return default(Tresult); }
}

/// <summary>
/// Returns column value from IDataRecord accecing by index.
/// </summary>
public static Tresult Value<Tresult>(this IDataRecord record, int field_index)
{
    return record.IsDBNull(field_index) ? default(Tresult) :
              (Tresult)Convert.ChangeType(record[field_index], typeof(Tresult));
}

我改变了我的 函数来反映您的想法,因此它看起来如下:

public static Tresult ValueIfExists2<Tresult>(this IDataRecord record, string field_name)
{
    for (int index = 0; index < record.FieldCount; index++)
    {
        if (record.GetName(index).Equals(field_name, StringComparison.InvariantCulture))
        {
            return record.Value<Tresult>(record.GetOrdinal(field_name));
        }
    }
    return default(Tresult);
}