我需要将 C# DataTable 转换为通用集合列表
DataTable Columns Respectively
1. EmpId (this is Int DataType)
2. EmpName (this is varchar DataType)
3. EmpAddress (this is varchar DataType)
4. EmpPhone (this is varchar DataType)
5. Status (this is Boolean DataType)
6. EmpRelationKey (this is int DataType)
所以我的 DataTable 包含上述字段的值。在这里我需要将这个值分配到我的列表中
我分别列出变量
class Employee
{
protected int EmpId ;
protected string EmpName =String.Empty;
protected string EmpAddress = String.Empty;
protected string EmpPhone = String.Empty;
protected bool Status ;
protected int EmpRelationKey ;
}
Declaring List
List<Employee> Emp= new List<Employee>
所以现在我需要将 DataTable 值分配给此列表。代码应该很专业。
我试过这个方法
List<Employee>employees = new List<Employee>();
foreach (DataRow row in dt.Rows)
{
employees.Add(new Employee
{
EmpId = Convert.ToInt32(row["EmpId"]),
EmpName = row["EmpName"].ToString() ,
EmpAddress = row["EmpName"].ToString(),
Emphone = row["EmpPhone"].ToString(),
Status = Convert.toBoolean(row["Status"])
});
}
但我不想提及列名，有没有其他方法可以在不提及 DataTable 中的每个列名的情况下分配值
using System.Reflection;
然后，
public static List<T> BindList<T>(DataTable dt)
{
// Example 1:
// Get private fields + non properties
//var fields = typeof(T).GetFields(BindingFlags.NonPublic | BindingFlags.Instance);
// Example 2: Your case
// Get all public fields
var fields = typeof(T).GetFields();
List<T> lst = new List<T>();
foreach (DataRow dr in dt.Rows)
{
// Create the object of T
var ob = Activator.CreateInstance<T>();
foreach (var fieldInfo in fields)
{
foreach (DataColumn dc in dt.Columns)
{
// Matching the columns with fields
if (fieldInfo.Name == dc.ColumnName)
{
// Get the value from the datatable cell
object value = dr[dc.ColumnName];
// Set the value into the object
fieldInfo.SetValue(ob, value);
break;
}
}
}
lst.Add(ob);
}
return lst;
}
使用示例:
DataTable dt1 = SqlHelper.GetTable("select * from employee;");
List<Employee> employees = BindList<Employee>(dt1);
DataTable dt2 = SqlHelper.GetTable("select * from membership;");
List<Membership> lstMembership = BindList<Membership>(dt2);
DataTable dt3 = SqlHelper.GetTable("select * from car order by name;");
List<Car> lstCar = BindList<Car>(dt3);
=====================
扩展版
以上示例假设数据表中的数据与您的类对象的字段具有相同的数据类型。
如果数据与类对象的字段不同怎么办？
比如null？
因此，您可能希望扩展该方法以防万一两种数据类型不同。
public static List<T> BindList<T>(DataTable dt)
{
// Example 1:
// Get private fields + non properties
//var fields = typeof(T).GetFields(BindingFlags.NonPublic | BindingFlags.Instance);
// Example 2: Your case
// Get all public fields
var fields = typeof(T).GetFields();
List<T> lst = new List<T>();
foreach (DataRow dr in dt.Rows)
{
// Create the object of T
var ob = Activator.CreateInstance<T>();
foreach (var fieldInfo in fields)
{
foreach (DataColumn dc in dt.Columns)
{
// Matching the columns with fields
if (fieldInfo.Name == dc.ColumnName)
{
Type type = fieldInfo.FieldType;
// Get the value from the datatable cell
object value = GetValue(dr[dc.ColumnName], type);
// Set the value into the object
fieldInfo.SetValue(ob, value);
break;
}
}
}
lst.Add(ob);
}
return lst;
}
static object GetValue(object ob, Type targetType)
{
if (targetType == null)
{
return null;
}
else if (targetType == typeof(String))
{
return ob + "";
}
else if (targetType == typeof(int))
{
int i = 0;
int.TryParse(ob + "", out i);
return i;
}
else if (targetType == typeof(short))
{
short i = 0;
short.TryParse(ob + "", out i);
return i;
}
else if (targetType == typeof(long))
{
long i = 0;
long.TryParse(ob + "", out i);
return i;
}
else if (targetType == typeof(ushort))
{
ushort i = 0;
ushort.TryParse(ob + "", out i);
return i;
}
else if (targetType == typeof(uint))
{
uint i = 0;
uint.TryParse(ob + "", out i);
return i;
}
else if (targetType == typeof(ulong))
{
ulong i = 0;
ulong.TryParse(ob + "", out i);
return i;
}
else if (targetType == typeof(double))
{
double i = 0;
double.TryParse(ob + "", out i);
return i;
}
else if (targetType == typeof(DateTime))
{
// do the parsing here...
}
else if (targetType == typeof(bool))
{
// do the parsing here...
}
else if (targetType == typeof(decimal))
{
// do the parsing here...
}
else if (targetType == typeof(float))
{
// do the parsing here...
}
else if (targetType == typeof(byte))
{
// do the parsing here...
}
else if (targetType == typeof(sbyte))
{
// do the parsing here...
}
else if........
..................
return ob;
}