c# - Tic tac toe vs computer class -

i writing tic tac toe game. logic in class that's why have difficulties. board matrix. firstly, put x when click button, computer choose block put o. in class save value of matrix element don't know how show on winform. here part of code..

public string togglenextletter() {         if (!changedletterx)         {             changedletterx = true;             return this.nextletter = "x";         }          changedletterx = false;         movecomputer();         return this.nextletter = "o"; } 

//reserve position of x form

public string[,] matrix(int row, int col, string value) {         this.field[row, col] = value;          return this.field;     }  public string[,] movecomputer()     {          //priority 1: tick tac toe         //priority 2: block x tic tac toe         //priority 3: go corner space         //priority 4: pick open space          string move;          move = lookforwinorblock("o"); //look win         if(move == null)         {             move = lookforwinorblock("x"); //look block             if (move == null)             {                 move = lookforcorner();                 if (move == null)                 {                     move = lookforopenspace();                 }             }         }          return move; }  private void btn_click(object sender, eventargs e) {         button btn = (button)sender;         int btnrow = convert.toint32(btn.tag) / 10;         int btncol = convert.toint32(btn.tag) % 10;         btn.text = game.togglenextletter();         game.matrix(btnrow, btncol, btn.text);         btn.enabled = false;         //btn.text = game.togglenextletter();          if (game.haswinner())         {             foreach (var control in controls)             {                 try                 {                     button b = (button)control;                     b.enabled = false;                 }                 catch { }             }             messagebox.show("the winner " + btn.text);         }     } 

just separate functions

public string[,] movecomputer() {     // add line     makeplay(btnrow, btncol, btntext);      return move; }   private void btn_click(object sender, eventargs e) {     button btn = (button)sender;     int btnrow = convert.toint32(btn.tag) / 10;     int btncol = convert.toint32(btn.tag) % 10;     btn.text = game.togglenextletter();     makeplay((btnrow, btncol, btn.text); }  private void makeplay(int btnrow, int btncol, string btntext) {     game.matrix(btnrow, btncol, btn.text);     btn.enabled = false;     //btn.text = game.togglenextletter();      if (game.haswinner())     {         foreach (var control in controls)         {             try             {                 button b = (button)control;                 b.enabled = false;             }             catch { }         }         messagebox.show("the winner " + btn.text);     } }