Questions about dynamically creating class instances

suguang

I wrote the code in the same namespace like this: (The main function is to create his instance based on the class name "String" that I wrote). The following code is valid:
namespace WindowsApplication1
{
    public partial class Form1: Form
    {
        public Form1 ()
        {
            InitializeComponent ();
            Type typ = Type.GetType ("WindowsApplication1.myCls");
            ConstructorInfo info = typ.GetConstructor (new Type [] {});
            info.Invoke (new object [] {});
            
        }
    }

    public class myCls
    {
        public myCls ()
        {
            MessageBox.Show ("");
        }
        public myCls (int a)
        {
            MessageBox.Show (a.ToString ());
        }
    }
}
If you move the above code, the code in the Form1 constructor to another class, and encapsulate it into a DLL, and then call the external class myCls again, you will be prompted to refer to the empty object. Why?

shygza

Did you add a DLL reference?
Is the namespace consistent after moving?

chali88

The description is not clear

suguang

The dll has been added to the reference, the results of the consistent and inconsistent namespaces are the same, I hope the heroes help

karimul

I also encountered this problem, and it seems that it can only be solved by reflection.
I don't know if it is feasible without reflection?

snowwhite

WindowsApplication1.myCls is just the name of the class, so if reflection is used, .NET will only find the definition of myCls in the current assembly (dll).

For example, if the Dll file name after Form1 and myCls are compiled is AAA.DLL, then use the following statement:

Type typ = Type.GetType("WindowsApplication1.myCls,AAA");

ntxydh

If you call this overloaded method, you will see an error message

Type typ = Type.GetType("WindowsApplication1.myCls", true);