C#读取对象实例的值和对对象的属性自动赋值方法

using System;

using System.Data;

using System.Reflection;

namespace DBUtility

{

/// <summary>

/// 对象实例操作辅助类

/// </summary>

public static class InstanceHelper

{

/// <summary>

/// 根据对象的属性名称，获取属性的值（用于根据对象自动完成参数化sql语句的赋值操作）

/// </summary>

/// <param name="propertyName">属性名称(忽略大小写)</param>

/// <param name="objectInstance">对象实例</param>

/// <param name="objectType">对象实例类型</param>

/// <returns>属性的值</returns>

public static object GetPropertyValue(string propertyName, object objectInstance, Type objectType)

{

PropertyInfo pi = objectType.GetProperty(propertyName, BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);

if (pi == null)

throw new ArgumentException("自动设置参数值失败。参数化变量名称" + propertyName + "必须和对象中的属性名称一样。");

if (!pi.CanRead)

throw new ArgumentException("自动设置参数值失败。对象的" + propertyName + "属性没有get方式，无法读取值。");

object value = pi.GetValue(objectInstance, null);

if (value == null)

value = DBNull.Value;

else if (pi.PropertyType.Name == "DateTime" && Convert.ToDateTime(value) == DateTime.MinValue)

value = DBNull.Value;//防止数据库是smalldatetime类型时DateTime.MinValue溢出

return value;

}

/// <summary>

/// 将DataReader中的数据自动赋值到对象实例对应的属性

/// 注意：对象实例的属性名称必须和数据库列名相同，可忽略大小写

/// </summary>

/// <param name="dataReader">SqlDataReader等数据阅读器获取的一行数据</param>

/// <param name="objectInstance">对象实例</param>

/// <param name="objectType">对象实例类型</param>

public static void SetPropertyValue(IDataReader dataReader, object objectInstance, Type objectType)

{

for (int i = 0; i < dataReader.FieldCount; i++)

{

PropertyInfo pi = objectType.GetProperty(dataReader.GetName(i), BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);

if (pi != null && pi.CanWrite && dataReader[i] != DBNull.Value)

{

//如果是int?、bool?、double?等这种可空类型，获取其实际类型，如int?的实际类型是int

Type baseType = Nullable.GetUnderlyingType(pi.PropertyType);

if (baseType != null)

pi.SetValue(objectInstance, Convert.ChangeType(dataReader[i], baseType), null);

else

pi.SetValue(objectInstance, Convert.ChangeType(dataReader[i], pi.PropertyType), null);//设置对象值

}

}

}

#region 用于Oracle数据库操作

/// <summary>

/// 根据对象的属性名称，获取属性的值（用于根据对象自动完成参数化sql语句的赋值操作）

/// </summary>

/// <param name="propertyName">属性名称(忽略大小写)</param>

/// <param name="objectInstance">对象实例</param>

/// <param name="objectType">对象实例类型</param>

/// <returns>属性的值</returns>

public static object GetPropertyValue2(string propertyName, object objectInstance, Type objectType)

{

PropertyInfo pi = objectType.GetProperty(propertyName, BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);

if (pi == null)

throw new ArgumentException("自动设置参数值失败。参数化变量名称必须和对象中的属性名称一样。");

if (!pi.CanRead)

throw new ArgumentException("自动设置参数值失败。对象的" + propertyName + "属性没有get方式，无法读取值。");

object value = pi.GetValue(objectInstance, null);

if (value == null)

value = DBNull.Value;

else if (pi.PropertyType.Name == "DateTime" && Convert.ToDateTime(value) == DateTime.MinValue)

value = DBNull.Value;

else if (pi.PropertyType.Name == "Boolean")//oracle数据库用char(1)作为bool类型

value = OraBit(Convert.ToBoolean(value));

return value;

}

/// <summary>

/// 将DataReader中的数据自动赋值到对象实例对应的属性

/// 注意：对象实例的属性名称必须和数据库列名相同，可忽略大小写

/// </summary>

/// <param name="dataReader">OracleDataReader获取的一行数据</param>

/// <param name="objectInstance">对象实例</param>

/// <param name="objectType">对象实例类型</param>

public static void SetPropertyValue2(IDataReader dataReader, object objectInstance, Type objectType)

{

for (int i = 0; i < dataReader.FieldCount; i++)

{

PropertyInfo pi = objectType.GetProperty(dataReader.GetName(i), BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);

if (pi != null && pi.CanWrite && dataReader[i] != DBNull.Value)

{

Type baseType = Nullable.GetUnderlyingType(pi.PropertyType);//获取其实际类型，如int?的实际类型是int

if (baseType != null)//如果是int?、bool?、double?等可空类型

{

if (baseType.Name == "Boolean")

pi.SetValue(objectInstance, OraBool(dataReader[i].ToString()), null);

else

pi.SetValue(objectInstance, Convert.ChangeType(dataReader[i], baseType), null);

}

else

{

if (pi.PropertyType.Name == "Boolean")

pi.SetValue(objectInstance, OraBool(dataReader[i].ToString()), null);

else

pi.SetValue(objectInstance, Convert.ChangeType(dataReader[i], pi.PropertyType), null);//设置对象值

}

}

}

}

/// <summary>

/// Converter to use boolean data type with Oracle

/// </summary>

/// <param name="value">Value to convert</param>

/// <returns></returns>

public static string OraBit(bool value)

{

if (value)

return "Y";

else

return "N";

}

/// <summary>

/// Converter to use boolean data type with Oracle

/// </summary>

/// <param name="value">Value to convert</param>

/// <returns></returns>

public static bool OraBool(string value)

{

if (value.Equals("Y"))

return true;

else

return false;

}

#endregion

}

}

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