dynamically load DLL exception when calling Activator.Creat eInstance(type, object[])

[Nancy Sui]

I am trying to dynamically load a dll which specifies different rules
for evalution with the following code.
DataRow dr = ds.Tables[0].Rows[0];
string fileName = Convert.ToStrin g(dr["RuleLocati on"]);
assemblyInstanc e = Assembly.Load( fileName );
typeInstance = assemblyInstanc e.GetType( "MSF.Storefront .Rules." +
dr["RuleName"].ToString() , true, false);
Object[] parameter = new Object[1];
if (seg == null)
parameter[0] = cs;
else
parameter[0] = seg;

rule = (Rules.IBaseRul e)Activator.Cre ateInstance(typ eInstance,
parameter);
return rule;

this code works fine if the rules are existing .cs files in the
current project and it loads it fine. The problem is when the program
is already running and then I add a new rule .dll into the bin folder,
then try to load that rule dynamically. I get an exception.

the exception i get is the MissingMethodEx ception, member cannot be
found. So then i create an empty constructor and pass in only the
typeInstance, i get a CastException. What is wrong? Please help.
Thanks.

[Scott Allen]

Nancy:

If I am reading the description of the problem correctly, then it
sounds as if you are trying to create an instance of a type that is in
an assembly that is not loaded. Are you using Assembly.LoadFi le
somewhere to bring that assembly into the process?

--
Scott
http://www.OdeToCode.com/blogs/scott/

On 29 Nov 2004 14:44:08 -0800, na******@gmail. com (Nancy Sui) wrote:

I am trying to dynamically load a dll which specifies different rules
for evalution with the following code.
DataRow dr = ds.Tables[0].Rows[0];
string fileName = Convert.ToStrin g(dr["RuleLocati on"]);
assemblyInstan ce = Assembly.Load( fileName );
typeInstance = assemblyInstanc e.GetType( "MSF.Storefront .Rules." +
dr["RuleName"].ToString() , true, false);
Object[] parameter = new Object[1];
if (seg == null)
parameter[0] = cs;
else
parameter[0] = seg;

rule = (Rules.IBaseRul e)Activator.Cre ateInstance(typ eInstance,
parameter);
return rule;

this code works fine if the rules are existing .cs files in the
current project and it loads it fine. The problem is when the program
is already running and then I add a new rule .dll into the bin folder,
then try to load that rule dynamically. I get an exception.

the exception i get is the MissingMethodEx ception, member cannot be
found. So then i create an empty constructor and pass in only the
typeInstance , i get a CastException. What is wrong? Please help.
Thanks.