//recommend reading:
// How to: Make Thread-Safe Calls to Windows Forms Controls
// https://docs.microsoft.com/en-us/dotnet/framework/winforms/controls/how-to-make-thread-safe-calls-to-windows-forms-controls
private void WriteOutput(string text)
{
if (this.Output1.InvokeRequired)
{
StringArgReturningVoidDelegate d = new StringArgReturningVoidDelegate(WriteOutput);
this.Invoke(d, new object[] { text });
}
else
{
Output1.Text = Output1.Text + text + "\n---------------\n";
Output1.SelectionStart = Output1.Text.Length;
Output1.ScrollToCaret();
}
}
