V WF

     private Button1[,] button1 = new Button1[9, 9];
     private int x,y;
   
    ....
    
    
      public class Button1 : Button
        {
            public int x, y;

            public Button1(int x, int y)
            {
                this.x = x;
                this.y = y;
            }
        }
        
        
    ....
   
    private void Form1_Load(object sender, EventArgs e)
        {

            for (int i = 0; i < 9; i++)
            {
                for (int y = 0; y < 9; y++)
                {
                    button1[i, y] = new Button1(i, y);
                    button1[i, y].MouseDown += new MouseEventHandler(event_MouseDown); //nastaví event  
                    label[i, y].BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
                    button1[i, y].Location = new Point(i * 50 + 50 + i, y * 50 + 50 + y);
                    button1[i, y].BackColor = Color.Bisque;
                    button1[i, y].AutoSize = false;
                    button1[i, y].BringToFront();
                    button1[i, y].Size = new System.Drawing.Size(50, 50);
                    button1[i, y].TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
                    button1[i, y].Font = new System.Drawing.Font("Microsoft Sans Serif", 30F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(238)));
                    this.Controls.Add(button1[i, y]);
                }
            }           
        }



            private void event_MouseDown(object sender, EventArgs e)
        {
            Button1 souradnice = (Button1)sender;
          
                button1[souradnice.x, souradnice.y].BackColor = Color.Coral;
                x = souradnice.x;
                y = souradnice.y;
                button1[x, y].Text = "?";                         
        }
   

Takto lze pracovat i s dalšími třídami a eventy.
K odebrání eventu použijeme znaménko mínus.

        button1[i, y].MouseDown -= new MouseEventHandler(event_MouseDown); //odebere event  
    

Vymazání celého panelu.

    private void btn_Click(object sender, EventArgs e)
   {
    panel1.Controls.Clear();  //vymaže vše z panelu   

    

Vymazání jednoho buttonů z formu.Pokud z cyklu nevyskočíme a buttonů je víc začne mazání zlobit.

    foreach (Control item in panel1.Controls.OfType<ComboBox>())//vymaže ComboBox z panelu  
    {
        panel1.Controls.Remove(item);
        break;               
    }


  
    foreach (Control item in panel1.Controls.OfType<Control>())//vymaže podle jména   
    {
        if (item.Name == "vymaz")
            panel1.Controls.Remove(item); 
            break; 
    }
    

Mazání více buttonů.

    for (int i = 0; i < this.Controls.Count; i++)
            {
                if (this.Controls[i].Name == "button")
                {
                    this.Controls.RemoveAt(i);
                    i--;
                }
            }      
    

Označení textu v textBoxu po cliknutí myší.

    private System.Windows.Forms.TextBox lastFocus; 
    
    
    ...
    
    t.Click += new EventHandler(event_Click);
    
    
    ...
    
     private void event_Click(object sender,  EventArgs e)
        {
           
            TextBox senderTextBox = sender as TextBox;
            if (lastFocus != senderTextBox)
            {
                senderTextBox.SelectAll();
            }
            lastFocus = senderTextBox;   
        }
  

V WPF

            TextBlock tb = new TextBlock();
            tb.VerticalAlignment = System.Windows.VerticalAlignment.Top;
            tb.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
            tb.Margin= new Thickness(20) ;
            tb.Text = "Nápis";
            tb.MouseDown += event_MouseDown;//nastaví event         
            wrapPanel1.Children.Add(tb);
  ------------------------------------------------------------------------------         
            
            private void event_MouseDown(object sender, MouseEventArgs e)
            {
              text.Text="jde to";
              wrapPanel1.Children.Clear();    //smaže wrapPanel         
            }