using System.Windows.Forms.DataVisualization.Charting;
...
private Thread addDataRunner;
private Random rand = new Random();
private System.Windows.Forms.DataVisualization.Charting.Chart chart1;
public delegate void AddDataDelegate();
public AddDataDelegate addDataDel;
...
private void RealTimeSample_Load(object sender, System.EventArgs e)
{
// create the Adding Data Thread but do not start until start button clicked
ThreadStart addDataThreadStart = new ThreadStart(AddDataThreadLoop);
addDataRunner = new Thread(addDataThreadStart);
// create a delegate for adding data
addDataDel += new AddDataDelegate(AddData);
}
private void startTrending_Click(object sender, System.EventArgs e)
{
// Disable all controls on the form
startTrending.Enabled = false;
// and only Enable the Stop button
stopTrending.Enabled = true;
// Predefine the viewing area of the chart
minValue = DateTime.Now;
maxValue = minValue.AddSeconds(120);
chart1.ChartAreas[0].AxisX.Minimum = minValue.ToOADate();
chart1.ChartAreas[0].AxisX.Maximum = maxValue.ToOADate();
// Reset number of series in the chart.
chart1.Series.Clear();
// create a line chart series
Series newSeries = new Series( "Series1" );
newSeries.ChartType = SeriesChartType.Line;
newSeries.BorderWidth = 2;
newSeries.Color = Color.OrangeRed;
newSeries.XValueType = ChartValueType.DateTime;
chart1.Series.Add( newSeries );
// start worker threads.
if ( addDataRunner.IsAlive == true )
{
addDataRunner.Resume();
}
else
{
addDataRunner.Start();
}
}
private void stopTrending_Click(object sender, System.EventArgs e)
{
if ( addDataRunner.IsAlive == true )
{
addDataRunner.Suspend();
}
// Enable all controls on the form
startTrending.Enabled = true;
// and only Disable the Stop button
stopTrending.Enabled = false;
}
/// Main loop for the thread that adds data to the chart.
/// The main purpose of this function is to Invoke AddData
/// function every 1000ms (1 second).
private void AddDataThreadLoop()
{
while (true)
{
chart1.Invoke(addDataDel);
Thread.Sleep(1000);
}
}
public void AddData()
{
DateTime timeStamp = DateTime.Now;
foreach ( Series ptSeries in chart1.Series )
{
AddNewPoint( timeStamp, ptSeries );
}
}
/// The AddNewPoint function is called for each series in the chart when
/// new points need to be added. The new point will be placed at specified
/// X axis (Date/Time) position with a Y value in a range +/- 1 from the previous
/// data point's Y value, and not smaller than zero.
public void AddNewPoint( DateTime timeStamp, System.Windows.Forms.DataVisualization.Charting.Series ptSeries )
{
double newVal = 0;
if ( ptSeries.Points.Count > 0 )
{
newVal = ptSeries.Points[ptSeries.Points.Count -1 ].YValues[0] + (( rand.NextDouble() * 2 ) - 1 );
}
if ( newVal < 0 )
newVal = 0;
// Add new data point to its series.
ptSeries.Points.AddXY( timeStamp.ToOADate(), rand.Next(10, 20));
// remove all points from the source series older than 1.5 minutes.
double removeBefore = timeStamp.AddSeconds( (double)(90) * ( -1 )).ToOADate();
//remove oldest values to maintain a constant number of data points
while ( ptSeries.Points[0].XValue < removeBefore )
{
ptSeries.Points.RemoveAt(0);
}
chart1.ChartAreas[0].AxisX.Minimum = ptSeries.Points[0].XValue;
chart1.ChartAreas[0].AxisX.Maximum = DateTime.FromOADate(ptSeries.Points[0].XValue).AddMinutes(2).ToOADate();
chart1.Invalidate();
}
/// Clean up any resources being used.
protected override void Dispose( bool disposing )
{
if ( (addDataRunner.ThreadState & ThreadState.Suspended) == ThreadState.Suspended)
{
addDataRunner.Resume();
}
addDataRunner.Abort();
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
...