如何确定数据列的类型是数字、字符串还是日期时间?

如果内置 TypeCode 枚举满足您的需要,然后您可以直接阅读 DataType 您的财产 DataColumn 然后打电话 GetTypeCode ,

TypeCode yourTypeCode = Type.GetTypeCode(yourDataColumn.DataType);

switch (yourTypeCode)
{
    case TypeCode.Byte:
    case TypeCode.SByte:
    case TypeCode.Int16
    case TypeCode.UInt16:
    case TypeCode.Int32:
    case TypeCode.UInt32:
    case TypeCode.Int64:
    case TypeCode.UInt64:
    case TypeCode.Single:
    case TypeCode.Double:
    case TypeCode.Decimal:
        Console.WriteLine("Numeric");
        break;
    case TypeCode.Boolean:
        Console.WriteLine("Bool");
        break;
    case TypeCode.DateTime:
        Console.WriteLine("DateTime");
        break;
    case TypeCode.String:
        Console.WriteLine("String");
        break;
    case TypeCode.Empty:
        Console.WriteLine("Null");
        break;
    default:    // TypeCode.DBNull, TypeCode.Char and TypeCode.Object
        Console.WriteLine("Unknown");
        break;
}

如果 类型码 不满足您的需要,那么您可以简单地将列类型转换为自己的自定义枚举,如中所述。 John's answer .

你可以使用:

var types = new Dictionary<Type, SomeEnum>()
{
    { typeof(int), SomeEnum.Numeric },
    { typeof(long), SomeEnum.Numeric },
    { typeof(string), SomeEnum.String },
    ...
};

Func<Type, object, SomeEnum> getTypeEnum = (type, obj) =>
{
    var result = types.ContainsKey(type)
                     ? types[type]
                     : SomeEnum.Unknown;
    if (obj == null || obj is DBNull)
    {
        result = SomeEnum.Null;
    }

    return result;
};

...

var e = getTypeEnum(col.DataType, row[col]);