怎么样去调用下面这个Get_XY()函数啊？


 public void Get_XY()
        {
            InfoBase infobase=new InfoBase ();
            float R_Na = infobase.R_Na;
            float R_Ca = infobase.R_Ca;

            float Na2 = 100 * R_Na / 23 / Y_Sum;
            float Na_x = -1 / 2 * Na2;
            float Na_y = -r * Na_x;
       }
 private void buttonX1_Click(object sender, EventArgs e)
        {              
            Graphics g = pictureBox1.CreateGraphics();
            g.TranslateTransform(halfWidth, halfHeight);
            g.Get_XY();（？）
            g.DrawLine(new Pen(Color.Red), Ca_x, Ca_y, Na_x, Na_y);
       }

能说详细点咯！

这样做呢？
public void Get_XY()
        {
            float R_Na;        
            float R_Ca ;
            float Na2 = 100 * R_Na / 23
            float Na_x = -1 / 2 * Na2;
            float Na_y = -1 * Na_x;
       }
private void buttonX1_Click(object sender, EventArgs e)
        {              
            Graphics g = pictureBox1.CreateGraphics();
            g.Get_XY();（就说这一步调用对吗？为什么上面已经声明这个函数了，下面的g就是不能去调用呢，如果说设置参数的话，又应该怎么做呢？）
            g.DrawLine(new Pen(Color.Red), Ca_x, Ca_y, Na_x, Na_y);//目的就是通过调用上面的函数，利用得出的Ca_x, Ca_y, Na_x, Na_y的这4个值画线；
       }