问题
I am trying to set a value to a Nested Property of Class dynamically using reflection. Could anyone help me to do this.
I am having a class Region
like below.
public class Region
{
public int id;
public string name;
public Country CountryInfo;
}
public class Country
{
public int id;
public string name;
}
I have a Oracle Data reader to provide the Values from the Ref cursor.
which will give me as
Id,name,Country_id,Country_name
I could able to assign the values to the Region.Id, Region.Name by below.
FieldName="id"
prop = objItem.GetType().GetProperty(FieldName, BindingFlags.Public | BindingFlags.Instance);
prop.SetValue(objItem, Utility.ToLong(reader_new[ResultName]), null);
And for the Nested Property I could able to do the assign values to the as below by creating a Instance by reading the Fieldname.
FieldName="CountryInfo.id"
if (FieldName.Contains('.'))
{
Object NestedObject = objItem.GetType().GetProperty(Utility.Trim(FieldName.Split('.')[0]), BindingFlags.Public | BindingFlags.Instance);
//getting the Type of NestedObject
Type NestedObjectType = NestedObject.GetType();
//Creating Instance
Object Nested = Activator.CreateInstance(typeNew);
//Getting the nested Property
PropertyInfo nestedpropinfo = objItem.GetType().GetProperty(Utility.Trim(FieldName.Split('.')[0]), BindingFlags.Public | BindingFlags.Instance);
PropertyInfo[] nestedpropertyInfoArray = nestedpropinfo.PropertyType.GetProperties();
prop = nestedpropertyInfoArray.Where(p => p.Name == Utility.Trim(FieldName.Split('.')[1])).SingleOrDefault();
prop.SetValue(Nested, Utility.ToLong(reader_new[ResultName]), null);
Nestedprop = objItem.GetType().GetProperty(Utility.Trim(FieldName.Split('.')[0]), BindingFlags.Public | BindingFlags.Instance);
Nestedprop.SetValue(objItem, Nested, null);
}
The above assign values to Country.Id
.
But Since I am creating instance each and every time I could not able to get the previous Country.Id
value if I go for the Next Country.Name.
Could anybody tell could to assign values to the objItem(that is Region).Country.Id
and objItem.Country.Name
. Which means how to assign values to the Nested Properties instead of creating instance and assigning everytime.
Thanks in advance.!
回答1:
You should be calling PropertyInfo.GetValue
using the Country
property to get the country, then PropertyInfo.SetValue
using the Id
property to set the ID on the country.
So something like this:
public void SetProperty(string compoundProperty, object target, object value)
{
string[] bits = compoundProperty.Split('.');
for (int i = 0; i < bits.Length - 1; i++)
{
PropertyInfo propertyToGet = target.GetType().GetProperty(bits[i]);
target = propertyToGet.GetValue(target, null);
}
PropertyInfo propertyToSet = target.GetType().GetProperty(bits.Last());
propertyToSet.SetValue(target, value, null);
}
回答2:
Get Nest properties e.g., Developer.Project.Name
private static System.Reflection.PropertyInfo GetProperty(object t, string PropertName)
{
if (t.GetType().GetProperties().Count(p => p.Name == PropertName.Split('.')[0]) == 0)
throw new ArgumentNullException(string.Format("Property {0}, is not exists in object {1}", PropertName, t.ToString()));
if (PropertName.Split('.').Length == 1)
return t.GetType().GetProperty(PropertName);
else
return GetProperty(t.GetType().GetProperty(PropertName.Split('.')[0]).GetValue(t, null), PropertName.Split('.')[1]);
}
来源:https://stackoverflow.com/questions/12294242/how-to-set-vaues-to-the-nested-property-using-c-sharp-reflection