Find type of nullable properties via reflection
I examine the properties of an object via reflection and continue processing the data type of each property. Here is my (reduced) source:
private void ExamineObjec开发者_运维技巧t(object o)
{
Type type = default(Type);
Type propertyType = default(Type);
PropertyInfo[] propertyInfo = null;
type = o.GetType();
propertyInfo = type.GetProperties(BindingFlags.GetProperty |
BindingFlags.Public |
BindingFlags.NonPublic |
BindingFlags.Instance);
// Loop over all properties
for (int propertyInfoIndex = 0; propertyInfoIndex <= propertyInfo.Length - 1; propertyInfoIndex++)
{
propertyType = propertyInfo[propertyInfoIndex].PropertyType;
}
}
My problem is, that I newly need to handle nullable properties, but I have no clue how to get the type of a nullable property.
possible solution:
propertyType = propertyInfo[propertyInfoIndex].PropertyType;
if (propertyType.IsGenericType &&
propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
{
propertyType = propertyType.GetGenericArguments()[0];
}
Nullable.GetUnderlyingType(fi.FieldType)
will do the work for you check below code for do the thing you want
System.Reflection.FieldInfo[] fieldsInfos = typeof(NullWeAre).GetFields();
foreach (System.Reflection.FieldInfo fi in fieldsInfos)
{
if (fi.FieldType.IsGenericType
&& fi.FieldType.GetGenericTypeDefinition().Equals(typeof(Nullable<>)))
{
// We are dealing with a generic type that is nullable
Console.WriteLine("Name: {0}, Type: {1}", fi.Name, Nullable.GetUnderlyingType(fi.FieldType));
}
}
foreach (var info in typeof(T).GetProperties())
{
var type = info.PropertyType;
var underlyingType = Nullable.GetUnderlyingType(type);
var returnType = underlyingType ?? type;
}
As pointed out by Yves M. it is as simple as below.
var properties = typeof(T).GetProperties();
foreach (var prop in properties)
{
var propType = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
var dataType = propType.Name;
}
I am using a loop to go through all class properties to get the property type. I use the following code:
public Dictionary<string, string> GetClassFields(TEntity obj)
{
Dictionary<string, string> dctClassFields = new Dictionary<string, string>();
foreach (PropertyInfo property in obj.GetType().GetProperties())
{
if (property.PropertyType.IsGenericType && property.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>) && property.PropertyType.GetGenericArguments().Length > 0)
dctClassFields.Add(property.Name, property.PropertyType.GetGenericArguments()[0].FullName);
else
dctClassFields.Add(property.Name, property.PropertyType.FullName);
}
return dctClassFields;
}
This method is easy, fast and safe
public static class PropertyInfoExtension {
public static bool IsNullableProperty(this PropertyInfo propertyInfo)
=> propertyInfo.PropertyType.Name.IndexOf("Nullable`", StringComparison.Ordinal) > -1;
}
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