DataTable转成List

//把一个Datatable 赋值给一个List对象

//定义一个转换类

public class ConvertTool
{
public static List<T> DataConvert<T>(DataTable tb)
{
List<T> lst = new List<T>();
DataConvert<T>(tb, ref lst);
return lst;
}

    public static List<T> DataConvert<T>(DataTable tb, ref List<T> lst)
    {
        for (int i = 0; i < tb.Rows.Count; i++)
        {
            lst.Add(DataConvert<T>(tb.Rows[i]));
        }
        return lst;
    }
    public static T DataConvert<T>(DataRow row)
    {
        var type = typeof(T);
        object obj = type.Assembly.CreateInstance(type.FullName);
        var c = (T)obj;
        DataConvert(row, ref c);
        return c;
    }

    public static T DataConvert<T>(DataRow row, ref T t)
    {
        var ps = t.GetType().GetProperties();
        var tbColumns = row.Table.Columns;
        foreach (var c in ps)
        {
            var colName = c.Name;
            if (tbColumns.Contains(colName))
            {
                object nr = row[colName] == DBNull.Value ? null : row[colName];
                if (nr == null)
                {
                    c.SetValue(t, nr, null);
                }
                else
                {
                    var nrType = c.PropertyType;
                    if (nrType == typeof(decimal) || nrType == typeof(decimal?))
                    {
                        nr = Convert.ToDecimal(nr);
                    }
                    else if (nrType == typeof(Int64) || nrType == typeof(Int64?))
                    {
                        nr = Convert.ToInt64(nr);
                    }
                    else if (nrType == typeof(double) || nrType == typeof(double?))
                    {
                        nr = Convert.ToDouble(nr);
                    }
                    else if (nrType == typeof(Int32) || nrType == typeof(Int32?))
                    {
                        nr = Convert.ToInt32(nr);
                    }
                    else if (nrType == typeof(Int16) || nrType == typeof(Int16?))
                    {
                        nr = Convert.ToInt16(nr);
                    }
                    c.SetValue(t, nr, null);
                }

            }
        }
        return t;
    }
}

定义一个测试的实体类

多种类型全部用上

public class TestClass
{
public int Id { get; set; }
public string Name { get; set; }
public decimal Money { get; set; }
public bool IsValid { get; set; }
public DateTime BirthDay { get; set; }

}

方法调用及显示结果

 public class Program
{
    static void Main(string[] args)
    {
        //定义一个DataTable 并赋值
        DataTable dt = new DataTable("dtTest");
        DataColumn dc = null;
        dc = dt.Columns.Add("Id", Type.GetType("System.Int32"));
        dc = dt.Columns.Add("Name", Type.GetType("System.String"));
        dc = dt.Columns.Add("Money", Type.GetType("System.Decimal"));
        dc = dt.Columns.Add("IsValid", Type.GetType("System.Boolean"));
        dc = dt.Columns.Add("BirthDay", Type.GetType("System.DateTime"));
        DataRow newRow;
        newRow = dt.NewRow();
        newRow["Id"] = "1";
        newRow["Name"] = "测试1";
        newRow["IsValid"] = true;
        newRow["Money"] = 100.00m;
        newRow["BirthDay"] = DateTime.Now ;
        dt.Rows.Add(newRow);

        newRow = dt.NewRow();
        newRow["Id"] = "2";
        newRow["Name"] = "测试2";
        newRow["IsValid"] = true;
        newRow["Money"] = 100.00m;
        newRow["BirthDay"] = DateTime.Now;
        dt.Rows.Add(newRow);

        //调用DataTable转成List
        List<TestClass> Li = ConvertTool.DataConvert<TestClass>(dt); 

        

    }
}

现在有很多流行的ORM框架，直接取出来对象数据很方便，不用再转。实现原理大同小异；