Solução do Exemplo1

#pragma once
namespace teste9 {
 using namespace System;
 using namespace System::ComponentModel;
 using namespace System::Collections;
 using namespace System::Windows::Forms;
 using namespace System::Data;
 using namespace System::Drawing;
 /// <summary>
 /// Summary for Form1
 ///
 /// WARNING: If you change the name of this class, you will need to change the
 ///          'Resource File Name' property for the managed resource compiler tool
 ///          associated with all .resx files this class depends on.  Otherwise,
 ///          the designers will not be able to interact properly with localized
 ///          resources associated with this form.
 /// </summary>
 public ref class Form1 : public System::Windows::Forms::Form
 {
   public:
     String ^aux;
     Form1(void)
     {
        InitializeComponent();
        //
        //TODO: Add the constructor code here
        //
     }
    private: System::Windows::Forms::Button^  button1;
    public: 
    protected:
         /// <summary>
         /// Clean up any resources being used.
         /// </summary>
          ~Form1()
          {
             if (components)
             {
                  delete components;
              }
          }
          private: System::Windows::Forms::TextBox^  textBox1;
          protected: 
          private:
              /// <summary>
              /// Required designer variable.
              /// </summary>
              System::ComponentModel::Container ^components;
#pragma region Windows Form Designer generated code
              /// <summary>
              /// Required method for Designer support - do not modify
              /// the contents of this method with the code editor.
              /// </summary>
              void InitializeComponent(void)
              {
                 this->textBox1 = (gcnew System::Windows::Forms::TextBox());
                 this->button1 = (gcnew System::Windows::Forms::Button());
                 this->SuspendLayout();
                 // 
                 // textBox1
                 // 
                 this->textBox1->Location = System::Drawing::Point(87, 84);
                 this->textBox1->Name = L"textBox1";
                 this->textBox1->Size = System::Drawing::Size(347, 20);
                 this->textBox1->TabIndex = 0;
                 this->textBox1->MouseUp += gcnew System::Windows::Forms::MouseEventHandler(this, &Form1::textBox1_MouseUp);
                 // 
                 // button1
                 // 
                 this->button1->Location = System::Drawing::Point(308, 233);
                 this->button1->Name = L"button1";
                 this->button1->Size = System::Drawing::Size(139, 71);
                 this->button1->TabIndex = 1;
                 this->button1->Text = L"Limpar";
                 this->button1->UseVisualStyleBackColor = true;
                 this->button1->Click += gcnew System::EventHandler(this, &Form1::button1_Click);
                 // 
                 // Form1
                 // 
                 this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
                 this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
                 this->ClientSize = System::Drawing::Size(554, 418);
                 this->Controls->Add(this->button1);
                 this->Controls->Add(this->textBox1);
                 this->Name = L"Form1";
                 this->Text = L"Form1";
                 this->ResumeLayout(false);
                 this->PerformLayout();
               }
#pragma endregion
       private: System::Void textBox1_MouseUp(System::Object^  sender, System::Windows::Forms::MouseEventArgs^  e) {
                                 aux = textBox1->SelectedText; 
                       }
       private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {                 			
                                  if(button1->Text == "Limpar")
                                  {   button1->Text = "Desfazer";
                                      textBox1->Text = "";
                                  }else
                                 {   button1->Text = "Limpar";
                                     textBox1->SelectedText = aux;    }	 

} }; }