How to create user control groupbox object in VC++?

I am trying to extend the groupbox class to a temp_groupbox class which includes two radiobuttons inside the groupbox. I am facing two problems. First, I don't know how to set the two lines of event handler code for the radiobuttons because I think I should set them in the window form class NOT in this temp_groupbox class. Am I right? Second, I can only see a groupbox (small, not the size that I set in this class. Basically, there is something wrong) in my window form and I cannot see any radiobutton (even if I delete those two lines of even handler code.) Please help

        public ref class temp_groupbox: public GroupBox
         {
         public: temp_groupbox(int a, int b, String ^groupboxname){
 
                       // Create and initialize a GroupBox and two RadioButton controls.
                         GroupBox^ groupBox1 = gcnew GroupBox;
                         RadioButton^ radioButton1 = gcnew RadioButton;
                         RadioButton^ radioButton2 = gcnew RadioButton;
 
                       // Add the RadioButtons to the GroupBox.
                         groupBox1->Controls->Add( radioButton1 );
                         groupBox1->Controls->Add( radioButton2 );
 
                         groupBox1->Location = System::Drawing::Point(a, b);
                         groupBox1->Size = System::Drawing::Size(800, 800);
                         groupBox1->TabIndex = 0;
                         groupBox1->TabStop = false;
 
                         radioButton1->Name = L"radioButton1";
                         radioButton2->Name = L"radioButton2";
 
 
                         radioButton1->Size = System::Drawing::Size(85, 17);
                         radioButton2->Size = System::Drawing::Size(85, 17);
 
                         radioButton1->Location = System::Drawing::Point(130, 40);
                         radioButton2->Location = System::Drawing::Point(40, 140);
 
                         radioButton1->TabIndex = 1;
                         radioButton1->TabStop = true;
 
                         radioButton2->TabIndex = 2;
                         radioButton2->TabStop = true;
 
                         radioButton1->UseVisualStyleBackColor = true;
                 ????radioButton1->CheckedChanged += gcnew System::EventHandler(this, radioButton1_CheckedChanged);
                         radioButton2->UseVisualStyleBackColor = true;
                 ????radioButton2->CheckedChanged += gcnew System::EventHandler(this, radioButton2_CheckedChanged);
                         groupBox1->SuspendLayout();
                         groupBox1->ResumeLayout(false);
                         groupBox1->PerformLayout();
             }
 
 
 
         };// end ref class
 

The following is the way that I call the temp_groupbox class form my window form class

            temp_groupbox^ Temp1 = gcnew  temp_groupbox(120, 130, "asd");
         Controls->Add(Temp1);
         SuspendLayout();
         ResumeLayout(false);
 

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