How to enable a start button after clicking stop buttons

I want to enable my start button after clicking all the three stop buttons.

I tried to place the button btn4.enabled = false inside the (sender == btn3), but the start button will be enabled if I first clicked on that button.

The three stop buttons can be clicked in random order.

Here's my code so far:

namespace SlotMachine
{
    class SlotMac
    {
        private Form f;
        Button btn1 = new Button(); // First stop
        Button btn2 = new Button(); // Second stop
        Button btn3 = new Button(); // Third stop
        Button btn4 = new Button(); // Start
        Timer Clock;    // Tick
        Timer Clock1;   // Tick
        Timer Clock2;   // Tick
        Int32 tick = 0;
        Label tb = new Label();
        int[] nNum = new int[3];

        public SlotMac()
        {
            f = new Form();
            f.Text = "Slot Machine";
            //f.Size = new Size(800, 700);
            f.FormBorderStyle = FormBorderStyle.FixedSingle;
        }

        PictureBox[] pics = new PictureBox[7];
        PictureBox[] pics1 = new PictureBox[7];
        PictureBox[] pics2 = new PictureBox[7];
        //PictureBox pb = new PictureBox();

        public void Launch()
        {
            Random r = new Random();
            int i = 0;
            //int x = 0;
            //int x = 50;

            tb.Location = new Point(205,20);
            f.Controls.Add(tb);

            Clock = new Timer();
            Clock.Interval = 800;
            Clock.Tick += new EventHandler(Clock_Tick);

            Clock1 = new Timer();
            Clock1.Interval = 800;
            Clock1.Tick += new EventHandler(Clock1_Tick);

            Clock2 = new Timer();
            Clock2.Interval = 800;
            Clock2.Tick += new EventHandler(Clock2_Tick);

            for (i = 0; i < pics.Length; i++)
            {
                pics[i] = new PictureBox();
                pics[0].Image = Image.FromFile(i + ".jpg");
                pics[i].SetBounds(50, 100, 100, 100);
                //x += 150;
                f.Controls.Add(pics[i]);
            }

            for (i = 0; i < pics1.Length; i++)
            {
                pics1[i] = new PictureBox();
                pics1[i].Image = Image.FromFile(i + ".jpg");
                pics1[i].SetBounds(200, 100, 100, 100);
                //x += 50;
                f.Controls.Add(pics1[i]);
            }

            for (i = 0; i < pics2.Length; i++)
            {
                pics2[i] = new PictureBox();
                pics2[i].Image = Image.FromFile(i + ".jpg");
                pics2[i].SetBounds(350, 100, 100, 100);
                //x += 50;
                f.Controls.Add(pics2[i]);
            }

            f.SetBounds(10, 20, 500, 500);

            // STOP
            btn1.Location = new Point(50, 250);
            btn1.Height = 40;
            btn1.Width = 100;
            f.Controls.Add(btn1);
            btn1.Text = "STOP";
            this.btn1.Click += new EventHandler(this.MyButtonClick);

            // STOP
            btn2.Location = new Point(200, 250);
            btn2.Height = 40;
            btn2.Width = 100;
            btn2.Text = "STOP";
            f.Controls.Add(btn2);
            this.btn2.Click += new EventHandler(this.MyButtonClick);

            // STOP
            btn3.Location = new Point(350, 250);
            btn3.Height = 40;
            btn3.Width = 100;
            btn3.Text = "STOP";
            f.Controls.Add(btn3);
            this.btn3.Click += new EventHandler(this.MyButtonClick);

            // START
            btn4.Location = new Point(200, 370);
            btn4.Height = 40;
            btn4.Width = 100;
            btn4.Text = "START";
            f.Controls.Add(btn4);
            this.btn4.Click += new EventHandler(btn4_Click);
            f.ShowDialog();
        }

        public void Clock_Tick(object sender, EventArgs e)
        {
            tick++;
            Random r = new Random();
            nNum[0] = r.Next(0, 6);
            for (int i = 0; i < pics.Length; i++)
            {
                pics[0].Image = Image.FromFile(nNum[0] + ".jpg");
                pics[1].Image = Image.FromFile(nNum[0] + ".jpg");
                pics[2].Image = Image.FromFile(nNum[0] + ".jpg");
                pics[3].Image = Image.FromFile(nNum[0] + ".jpg");
                pics[4].Image = Image.FromFile(nNum[0] + ".jpg");
                pics[5].Image = Image.FromFile(nNum[0] + ".jpg");
                pics[6].Image = Image.FromFile(nNum[0] + ".jpg");
            }
        }

        public void Clock1_Tick(object sender, EventArgs e)
        {
            tick++;
            Random r = new Random();
            nNum[1] = r.Next(0, 6);
            for (int i = 0; i < pics.Length; i++)
            {
                pics1[0].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[1].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[2].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[3].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[4].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[5].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[6].Image = Image.FromFile(nNum[1] + ".jpg");
            }
        }

        public void Clock2_Tick(object sender, EventArgs e)
        {
            tick++;
            Random r = new Random();
            nNum[2] = r.Next(0, 6);
            for (int i = 0; i < pics.Length; i++)
            {
                pics2[0].Image = Image.FromFile(nNum[2] + ".jpg");
                pics1[1].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[2].Image = Image.FromFile(nNum[1] + ".jpg");
   开发者_开发问答             pics1[3].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[4].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[5].Image = Image.FromFile(nNum[1] + ".jpg");
                pics1[6].Image = Image.FromFile(nNum[1] + ".jpg");
            }
        }

        public void MyButtonClick(object sender, EventArgs e)
        {
            if (sender == btn1)
            {
                Clock.Stop();
            }

            if (sender == btn2)
            {
                Clock1.Stop();
            }

            if (sender == btn3)
            {
                Clock2.Stop();
            }
            Finish();
        }

        public void btn4_Click(object sender, EventArgs e)
        {
            Clock.Start();
            Clock1.Start();
            Clock2.Start();
            btn4.Enabled = false;
        }

        public void Finish()
        {
            if (nNum[0] == nNum[1] && nNum[0] == nNum[2])
            {
                this.tb.Text = "Congratulations!";
            }
        }
    }
}

You can check if all timers already stopped, like this:

public void MyButtonClick(object sender, EventArgs e)
{

    if (sender == btn1)
    {
        Clock.Stop();
    }

    if (sender == btn2)
    {
        Clock1.Stop();
    }

    if (sender == btn3)
    {
        Clock2.Stop();
    }
    Finish();

    if(!Clock.Enabled && !Clock1.Enabled && !Clock2.Enabled)
       btn4.Enabled = true;
}

Try this for method MyButtonClick:

public void MyButtonClick(object sender, EventArgs e)
{

    if (sender == btn1)
    {
        Clock.Stop();
    }

    if (sender == btn2)
    {
        Clock1.Stop();
    }

    if (sender == btn3)
    {
        Clock2.Stop();
    }
    Finish();

   if (!Clock.Enabled && !Clock1.Enabled && !Clock2.Enabled) btn4.Enabled = true;
}

You could disable each button as they are clicked (which would make sense) and then after they are all disabled, enable the Start button.

if (sender == btn1)
{
    Clock.Stop();
    btn1.Enabled = false; // disable the buttons after they are clicked.
}

if (sender == btn2)
{
    Clock1.Stop();
    btn2.Enabled = false;
}

if (sender == btn3)
{
    Clock2.Stop();
    btn3.Enabled = false;
}

// If all buttons are disabled then enable the Start button.
if (!btn1.Enabled && !btn2.Enabled && !btn3.Enabled)
{
    btn4.Enabled = true;
}

Finish();