graph is vanished in tabpage

[jagadeeshv]

Hi,
this is jagadeesh, iam visual studio 10 IDE and c# language for one grafical application .
for that application i used tabpages, one of that tab pages i have to draw graph in that page.it works also but while i selected another page the control goes to that page, after return to graph page the graph is vanished.but i didn't want that .any body can help abiut this problem.

thankyou,

[rliq]

1) How are you drawing the graph?
2) In which part of your code are you drawing the graph?

Post some of your code here.

[jagadeeshv]

here iam sending my sample code which is run in timer block
this graph raises between voltage and time

private void timer1_Tick_1(object sender, EventArgs e)
{
  Graphics g = this.tabLoadPage.CreateGraphics();
  //System.Drawing.Drawing2D.GraphicsState graph = g.Save();
  //g.Restore(graph);
  if (flg == true)
  {

    y1 = y2;
    x2 = x2 + 5; // for increse time leve
    flg = false;

  }
  else if (flg == false)
  {
    x1 = x2;      // here i iam taking reference point of time level
    y2 = Convert.ToInt16(398 - ((dta[load_val] / 1000) * 32.25)); ; // for increse voltage level
    flg = true;
  }
  g.DrawLine(p, x1, y1, x2, y2);
}

this code was working in tabpage1(tabloadpage).if i press next tab page ,the controll goes to that age at that time graph is vanished .this is my problem please help me
thank you,

[jagadeeshv]

the timer was refereshed for every 1 second

[rliq]

You need to draw all of the lines every time in your Paint handler.

I just wrote this code, it may help you make some progress.

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        List<Point> _points = new List<Point>();

        Random _random = new Random();
       
        public Form1()
        {
            InitializeComponent();

            // at least two points are required...
            _points.Add(new Point(0, 0));
            _points.Add(new Point(this.Width, this.Height));

            timer1.Start();
        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            g.DrawLines(Pens.Blue, _points.ToArray());
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            _points.Add(new Point(_random.Next(this.Width), _random.Next(this.Height)));
            this.Invalidate();
        }
    }
}

[jagadeeshv]

Thank you Sir, your suggestion is useful to me.