Deserialization problem. Can't set value of new field

[Joe]

Hello,

I'm trying to deserialize my objects (which derive from CollectionBase)
using the special constructor. Everything works fine until I go to set the
value. I get the following error:
"Object type cannot be converted to target type."

The property Value of newField = 'ArrayList' and val also shows as
ArrayList'.

What could be wrong?

public MyCollection(SerializationInfo info, StreamingContext context)
{
Type entityType = this.GetType();

string fieldName = string.Empty;

foreach (SerializationEntry entry in info)
{
fieldName = entry.Name;

if (fieldName.IndexOf('+') > -1 )
{
string []names = fieldName.Split('+');
string baseType = names[0];

fieldName = names[1];

while (entityType.Name != baseType)
entityType = entityType.BaseType;
}
else
entityType = this.GetType();

MemberInfo []members = entityType.GetMember(fieldName,
MemberTypes.Field, BindingFlags.NonPublic |
BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);

if (members.Length > 0)
{
FieldInfo newField = members[0] as FieldInfo;

object val = entry.Value;

if (val != null)
{
if (!newField.FieldType.IsInstanceOfType(val) )
val = Convert.ChangeType(val, newField.FieldType);
}

try
{
// throws error - "Object type cannot be converted to target type."
newField.SetValue(entry, val);
}
catch (Exception ex)
{
int stop = 0;
}
}
}
}

Many thanks,
Joe

 

[Joe]

I sort of worked around this by creating a Surrogate class for the
BinaryFormatter.

My next problem is to deal with new members which are initialized in the
constructor.

I added a new field to my class (a hashtable) and now when the class is
deserialized that member doesn't get initialized. Is there a way to handle
this using the Surrogate?

 

[Joe]

Never mind. I can implement IDeserializationCallback.

I sort of worked around this by creating a Surrogate class for the
BinaryFormatter.

My next problem is to deal with new members which are initialized in the
constructor.

I added a new field to my class (a hashtable) and now when the class is
deserialized that member doesn't get initialized. Is there a way to handle
this using the Surrogate?

Hello,

I'm trying to deserialize my objects (which derive from CollectionBase)
using the special constructor. Everything works fine until I go to set
the value. I get the following error:
"Object type cannot be converted to target type."

The property Value of newField = 'ArrayList' and val also shows as
ArrayList'.

What could be wrong?

public MyCollection(SerializationInfo info, StreamingContext context)
{
Type entityType = this.GetType();

string fieldName = string.Empty;

foreach (SerializationEntry entry in info)
{
fieldName = entry.Name;

if (fieldName.IndexOf('+') > -1 )
{
string []names = fieldName.Split('+');
string baseType = names[0];

fieldName = names[1];

while (entityType.Name != baseType)
entityType = entityType.BaseType;
}
else
entityType = this.GetType();

MemberInfo []members = entityType.GetMember(fieldName,
MemberTypes.Field, BindingFlags.NonPublic |
BindingFlags.NonPublic | BindingFlags.Public |
BindingFlags.Instance);

if (members.Length > 0)
{
FieldInfo newField = members[0] as FieldInfo;

object val = entry.Value;

if (val != null)
{
if (!newField.FieldType.IsInstanceOfType(val) )
val = Convert.ChangeType(val, newField.FieldType);
}

try
{
// throws error - "Object type cannot be converted to target type."
newField.SetValue(entry, val);
}
catch (Exception ex)
{
int stop = 0;
}
}
}
}

Many thanks,
Joe