private void ShowProgress(int i)
{
if (lblOutput.InvokeRequired)
{
// This is hit if a background thread calls ShowProgress()
var showProgressDel = new ShowProcessDelegate(ShowProgress);
this.BeginInvoke(showProgressDel, new object[] { i });
}
else
{
lblOutput.Text = i.ToString();
pbStatus.Value = i;
}
}
private void ShowProgress(int i)
{
// this is hit if a background thread calls ShowProgress
if (lblOutput.InvokeRequired)
{
// trick here is to assign the ShowProcess method to ShowProcessDelegate
var del = new ShowProcessDelegate(ShowProgress);
this.BeginInvoke(del, new object[] { i });
}
else
{
lblOutput.Text = i.ToString();
pbStatus.Value = i;
}
}
//update of controls will takes place here
private void ShowProgress(int i)
{
//1- we need to check if a label needs to be invoked in the GUI thread
// - you can do that using "InvokeRequired" property
if (lblOutput.InvokeRequired == true)
{
// 2- if true this is hit by a background thread, so route the data from the background thread to the main thread
// we need to use another delegate and pass the data(i) to the GUI Thread.
// so we need to integrate another delegate with another async invocation, but this particular delegate
// will be involved of routing the data from the background thread to main thread.
// recursive call
var del = new ShowProcessDelegate(ShowProgress);
// using the word "this" which represent the "form" (main thread) with "BeginInvoke" will make
// the main thread to run, so we re call the function and "else" will be hit, because "InvokeRequired" will be false
this.BeginInvoke(del, new Object[] { i });
}
else
{
lblOutput.Text = i.ToString();
pbStatus.Value = i;
}
}
void ShowProgress(string pi, int totalDigits, int digitsSoFar, out bool cancel)
{
if (_pi.InvokeRequired == false) // UI thread running
{
cancel = _calcState == CalcState.Canceled;
if (cancel)
{
_calcState = CalcState.Pending;
_calcButton.Enabled = true;
_calcButton.Text = "Calc";
}
_pi.Text = pi;
_piProgress.Maximum = totalDigits;
_piProgress.Value = digitsSoFar;
}
else
{
ShowProcessDelegate del = new ShowProcessDelegate(ShowProgress);
object[] args = { pi, totalDigits, digitsSoFar, null };
this.Invoke(del, args);
cancel = (bool)args[3];
}
}
