C#将DataTable转换成list的方法

将DataTable转换成List是C#开发中常见的需求，下面是将DataTable转换成List的完整攻略。

步骤1：创建实体类

创建一个实体类作为转换后的对象类型。实体类中的属性需要与DataTable中的列对应。

public class Person
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
}

步骤2：将DataTable转换成List

可以使用LINQ或者foreach循环遍历DataTable并将每一行转换成实体类。

方法一：使用LINQ

List<Person> personList = dataTable.AsEnumerable().Select(row => new Person
{
    Id = row.Field<int>("Id"),
    Name = row.Field<string>("Name"),
    Age = row.Field<int>("Age")
}).ToList();

方法二：使用foreach循环

List<Person> personList = new List<Person>();
foreach (DataRow row in dataTable.Rows)
{
    Person person = new Person
    {
        Id = Convert.ToInt32(row["Id"]),
        Name = row["Name"].ToString(),
        Age = Convert.ToInt32(row["Age"])
    };
    personList.Add(person);
}

示例一：从数据库中读取数据转换成List

using (SqlConnection conn = new SqlConnection("Data Source=.;Initial Catalog=TestDB;Integrated Security=True"))
{
    conn.Open();
    SqlCommand cmd = new SqlCommand("SELECT * FROM Persons", conn);
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    DataTable dataTable = new DataTable();
    adapter.Fill(dataTable);

    List<Person> personList = dataTable.AsEnumerable().Select(row => new Person
    {
        Id = row.Field<int>("Id"),
        Name = row.Field<string>("Name"),
        Age = row.Field<int>("Age")
    }).ToList();
}

示例二：从CSV文件中读取数据转换成List

using (var reader = new StreamReader("path/to/csv/file.csv"))
using (var csv = new CsvReader(reader, CultureInfo.InvariantCulture))
{
    var records = csv.GetRecords<dynamic>();
    DataTable dataTable = new DataTable();
    foreach (var record in records)
    {
        IDictionary<string, object> dictRecord = record as IDictionary<string, object>;
        if (dataTable.Columns.Count == 0)
        {
            foreach (var key in dictRecord.Keys)
            {
                dataTable.Columns.Add(key);
            }
        }
        DataRow dataRow = dataTable.NewRow();
        foreach (var key in dictRecord.Keys)
        {
            dataRow[key] = dictRecord[key];
        }
        dataTable.Rows.Add(dataRow);
    }

    List<Person> personList = new List<Person>();
    foreach (DataRow row in dataTable.Rows)
    {
        Person person = new Person
        {
            Id = Convert.ToInt32(row["Id"]),
            Name = row["Name"].ToString(),
            Age = Convert.ToInt32(row["Age"])
        };
        personList.Add(person);
    }
}

以上就是将DataTable转换成List的完整攻略。