private void Form1_Load(object sender, EventArgs e) { DigitTextBox1 = new DigitTextBox(); DigitTextBox1.Name = "DigitTextBox1"; DigitTextBox1.Location = new System.Drawing.Point(80, 15); DigitTextBox1.Size = new System.Drawing.Size(80, 10); DigitTextBox1.TabIndex = 1; DigitTextBox1.Text = ""; DigitTextBox2 = new DigitTextBox(); DigitTextBox2.Name = "DigitTextBox2"; DigitTextBox2.Location = new System.Drawing.Point(80, 40); DigitTextBox2.Size = new System.Drawing.Size(80, 10); DigitTextBox2.TabIndex = 2; DigitTextBox2.Text = ""; this.Controls.Add(DigitTextBox1); this.Controls.Add(DigitTextBox2); try //Try to get an active instance of Inventor { try { m_inventorApp = System.Runtime.InteropServices.Marshal.GetActiveObject("Inventor.Application") as Inventor.Application; } catch { Type inventorAppType = System.Type.GetTypeFromProgID("Inventor.Application"); m_inventorApp = System.Activator.CreateInstance(inventorAppType) as Inventor.Application; //Must be set visible explicitly m_inventorApp.Visible = true; } } catch { System.Windows.Forms.MessageBox.Show("Error: couldn't create Inventor instance"); } }