How can I use c# picturebox to show matlab‘ fig？

I want show fig in my c# picturebox.It will show a messagebox “Application error--0xe0434f4d and 0x7c812aeb"

main code of C#:

st.mathplot((MWNumericArray)mt_a, (MWNumericArray)mt_d, (MWCharArray)mt_c, (MWCharArray)mt_xlab, (MWCharArray)mt_ylab);
            //string command1;
            String path = Directory.GetCurrentDirectory();
            path = path + "C:\test1.jpg";

              pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
              pictureBox1.Image = Image.FromFile(path);

the st.mathplot is matlab'file like:

function mathplot(h,D,xlabel1,ylabel1,title1)
for x=-10:0.1:10,
   if x>D
   y=h;
   hold on;
   xlabel(xlabel1);
   ylabel(ylabel1);
   title(title1);
   plot(x,y);
   elseif x<-D
   y=-h; 
   hold on;
   xlabel(xlabel1);
   ylabel(ylabel1);
   title(title1);
   plot(x,y);

     else
     y=h/(D*x);
     hold on;
     xlabel(xlabel1);
     ylabel(ylabel1);
     title(title1);
     plot(x,y);
     set(gcf,'color',[1,1,1]); 
     %mkdir image;
        % ========================
     saveas(gcf,'C:\test1.jpg','jpg')
     end
  end