MysqlHelper使用反射机制智能推算数据类型以及属性名称
时间：2021-07-01 10:21:17
帮助过：3人阅读
class MySqlHelper
{
private string ConnString;
public MySqlHelper(
string connectionString)
{
ConnString =
connectionString;
}
public IList<T> RunMySqlSelect4ReturnList<T>(
string strCommand)
where T :
new()
{
MySqlCommand mySqlCommand =
new MySqlCommand();
mySqlCommand.CommandText =
strCommand.ToString();
IList<PropertyInfo> ilPropertyInfo =
typeof(T).GetProperties().ToList();
//p[0].Name =travel_id;
IList<T> ilResult =
new List<T>
();
DataTable dt =
new DataTable();
using (MySqlConnection conn =
new MySqlConnection(
this.ConnString))
{
conn.Open();
using (MySqlCommand cmd =
mySqlCommand)
{
cmd.Connection =
conn;
using (MySqlDataReader rdr =
cmd.ExecuteReader(CommandBehavior.SequentialAccess))
{
dt.Load(rdr);
}
}
}
foreach (DataRow dr
in dt.Rows)
{
T tItem =
new T();
foreach (
var v
in ilPropertyInfo)
{
if (dt.Columns[v.Name] ==
null)
continue;
ConvertionExtensions.SetValue(tItem, v.Name, dr[v.Name]);
}
ilResult.Add(tItem);
}
return ilResult;
}
public T getSinggleObj<T>(
string strCommand)
where T :
new()
{
MySqlCommand mySqlCommand =
new MySqlCommand();
mySqlCommand.CommandText =
strCommand.ToString();
IList<PropertyInfo> ilPropertyInfo =
typeof(T).GetProperties().ToList();
//p[0].Name =travel_id;
T ilResult =
new T();
DataTable dt =
new DataTable();
using (MySqlConnection conn =
new MySqlConnection(
this.ConnString))
{
conn.Open();
using (MySqlCommand cmd =
mySqlCommand)
{
cmd.Connection =
conn;
using (MySqlDataReader rdr =
cmd.ExecuteReader(CommandBehavior.SequentialAccess))
{
dt.Load(rdr);
}
}
}
if (dt.Rows.Count <=
0)
{
return default(T);
}
else
{
foreach (DataRow dr
in dt.Rows)
{
T tItem =
new T();
foreach (
var v
in ilPropertyInfo)
{
if (dt.Columns[v.Name] ==
null)
continue;
ConvertionExtensions.SetValue(tItem, v.Name, dr[v.Name]);
}
ilResult =
tItem;
}
}
return ilResult;
}
public IList<T> RunMySqlSelect4ReturnList<T>(DataTable dts)
where T :
new()
{
IList<PropertyInfo> ilPropertyInfo =
typeof(T).GetProperties().ToList();
//p[0].Name =travel_id;
IList<T> ilResult =
new List<T>
();
DataTable dt =
dts;
foreach (DataRow dr
in dt.Rows)
{
T tItem =
new T();
foreach (
var v
in ilPropertyInfo)
{
if (dt.Columns[v.Name] ==
null)
continue;
ConvertionExtensions.SetValue(tItem, v.Name, dr[v.Name]);
}
ilResult.Add(tItem);
}
return ilResult;
}
}
public static class ConvertionExtensions
{
public static T ConvertTo<T>(
this IConvertible convertibleValue)
{
var t =
typeof(T);
if (
null ==
convertibleValue)
{
return default(T);
}
if (!
typeof(T).IsGenericType)
{
return (T)Convert.ChangeType(convertibleValue,
typeof(T));
}
else
{
Type genericTypeDefinition =
typeof(T).GetGenericTypeDefinition();
if (genericTypeDefinition ==
typeof(Nullable<>
))
{
return (T)Convert.ChangeType(convertibleValue, Nullable.GetUnderlyingType(
typeof(T)));
}
}
throw new InvalidCastException(
string.Format(
"Invalid cast from type \"{0}\" to type \"{1}\".", convertibleValue.GetType().FullName,
typeof(T).FullName));
}
public static void SetValue(
object inputObject,
string propertyName,
object propertyVal)
{
//find out the type
Type type =
inputObject.GetType();
//get the property information based on the type
System.Reflection.PropertyInfo propertyInfo =
type.GetProperty(propertyName);
//find the property type
Type propertyType =
propertyInfo.PropertyType;
//Convert.ChangeType does not handle conversion to nullable types
//if the property type is nullable, we need to get the underlying type of the property
var targetType = IsNullableType(propertyInfo.PropertyType) ?
Nullable.GetUnderlyingType(propertyInfo.PropertyType) : propertyInfo.PropertyType;
//Returns an System.Object with the specified System.Type and whose value is
//equivalent to the specified object.
propertyVal =
Convert.ChangeType(propertyVal, targetType);
//Set the value of the property
propertyInfo.SetValue(inputObject, propertyVal,
null);
}
private static bool IsNullableType(Type type)
{
return type.IsGenericType && type.GetGenericTypeDefinition().Equals(
typeof(Nullable<>
));
}
}
MysqlHelper使用反射机制智能推算数据类型以及属性名称
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