在您的特定情况下(所有过程都有相同的列，只有一个过程有额外的一列)，检查阅读器的FieldCount属性来区分它们会更好、更快。

const int NormalColCount = .....
if(reader.FieldCount > NormalColCount)
{
    // Do something special
}

您还可以(出于性能原因)将此解决方案与解决方案迭代解决方案混合使用。

这对我来说很管用:

public static class DataRecordExtensions
{
    public static bool HasColumn(IDataReader dataReader, string columnName)
    {
        dataReader.GetSchemaTable().DefaultView.RowFilter = $"ColumnName= '{columnName}'";
        return (dataReader.GetSchemaTable().DefaultView.Count > 0);
    }
}

对于这个简单的问题，我建议使用try{} catch{}。但是，我不建议在catch中处理异常。

try 
{
  if (string.IsNullOrEmpty(reader["Name"].ToString())) 
  {
    name = reader["Name"].ToString();
  }
}
catch
{
  //Do nothing
}

在一行中，在DataReader检索后使用:

var fieldNames = Enumerable.Range(0, dr.FieldCount).Select(i => dr.GetName(i)).ToArray();

然后,

if (fieldNames.Contains("myField"))
{
    var myFieldValue = dr["myField"];
    ...

Edit

更高效的单行程序，不需要加载模式:

var exists = Enumerable.Range(0, dr.FieldCount).Any(i => string.Equals(dr.GetName(i), fieldName, StringComparison.OrdinalIgnoreCase));

整个问题的关键在这里:

if (-1 == index) {
    throw ADP.IndexOutOfRange(fieldName);
}

如果引用的三行(目前是第72、73和74行)被删除，那么您可以很容易地检查-1，以确定列是否不存在。

确保本机性能的唯一方法是使用基于反射的实现，如下所示:

Usings:

using System;
using System.Data;
using System.Reflection;
using System.Data.SqlClient;
using System.Linq;
using System.Web.Compilation; // I'm not sure what the .NET Core equivalent to BuildManager.cs

基于反射的扩展方法:

/// Gets the column ordinal, given the name of the column.
/// </summary>
/// <param name="reader"></param>
/// <param name="name">The name of the column.</param>
/// <returns> The zero-based column ordinal. -1 if the column does not exist.</returns>
public static int GetOrdinalSoft(this SqlDataReader reader, string name)
{
    try
    {
        // Note that "Statistics" will not be accounted for in this implemenation
        // If you have SqlConnection.StatisticsEnabled set to true (the default is false), you probably don't want to use this method
        // All of the following logic is inspired by the actual implementation of the framework:
        // https://referencesource.microsoft.com/#System.Data/fx/src/data/System/Data/SqlClient/SqlDataReader.cs,d66096b6f57cac74
        if (name == null)
            throw new ArgumentNullException("fieldName");

        Type sqlDataReaderType = typeof(SqlDataReader);
        object fieldNameLookup = sqlDataReaderType.GetField("_fieldNameLookup", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(reader);
        Type fieldNameLookupType;
        if (fieldNameLookup == null)
        {
            MethodInfo checkMetaDataIsReady = sqlDataReaderType.GetRuntimeMethods().First(x => x.Name == "CheckMetaDataIsReady" && x.GetParameters().Length == 0);
            checkMetaDataIsReady.Invoke(reader, null);
            fieldNameLookupType = BuildManager.GetType("System.Data.ProviderBase.FieldNameLookup", true, false);
            ConstructorInfo ctor = fieldNameLookupType.GetConstructor(new[] { typeof(SqlDataReader), typeof(int) });
            fieldNameLookup = ctor.Invoke(new object[] { reader, sqlDataReaderType.GetField("_defaultLCID", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(reader) });
        }
        else
            fieldNameLookupType = fieldNameLookup.GetType();

        MethodInfo indexOf = fieldNameLookupType.GetMethod("IndexOf", BindingFlags.Public | BindingFlags.Instance, null, new Type[] { typeof(string) }, null);

        return (int)indexOf.Invoke(fieldNameLookup, new object[] { name });
    }
    catch
    {
        // .NET Implemenation might have changed, revert back to the classic solution.
        if (reader.FieldCount > 11) // Performance observation by b_levitt
        {
            try
            {
                return reader.GetOrdinal(name);
            }
            catch
            {
                return -1;
            }
        }
        else
        {
            var exists = Enumerable.Range(0, reader.FieldCount).Any(i => string.Equals(reader.GetName(i), name, StringComparison.OrdinalIgnoreCase));
            if (exists)
                return reader.GetOrdinal(name);
            else
                return -1;
        }
    }
}

我也没有让GetSchemaTable工作，直到我发现了这种方法。

基本上我是这样做的:

Dim myView As DataView = dr.GetSchemaTable().DefaultView
myView.RowFilter = "ColumnName = 'ColumnToBeChecked'"

If myView.Count > 0 AndAlso dr.GetOrdinal("ColumnToBeChecked") <> -1 Then
  obj.ColumnToBeChecked = ColumnFromDb(dr, "ColumnToBeChecked")
End If