How to get string length

[Mindset]

Hi
I developed a simple indicator here that shows the high and the low of the current bar or any other prior bar.

I have had a request to reduce the footprint of this indicator.

so.. if I have a price of say 4006.5 what I want to do is to show 06.5.

How do I measure the string length please and how do I access the correct characters?

I use the following in a DrawText line curently.

string decstr = "N" + Decimal.ToString();//Dec places
string lowstr = "   " + (Low[NBar] - TickSize).ToString(decstr);

I have found the word MeasureString but somehow I can't seem to get it to work!?

[NinjaTrader_JoshP]

Hi Mindset,

This is C# string manipulation. Google "C# string manipulation". You will find several links showing you different methods of how to get what you want. Good luck.

[Mindset]

so slow

Hi Josh

Ok found what I wanted and incorporated it into my simple indicator.
it now loads up like glue - I am talking 25seconds to change an input per chart. Ironically the msdn says this string manipulation is particularly fast so is it the way it's coded?

[ protected override void OnBarUpdate()
{
if (Historical) return;


string decstr = "N" + Decimal.ToString();//Dec places
string finallow = (( Low[NBar]- TickSize).ToString(decstr)).Substring(Chars);// Chars is an Input int variable
string finalhigh = ( (High[NBar] + TickSize).ToString(decstr).Substring(Chars));



//SizeF size = MeasureString(lowstr.ToString(decstr), txtFont);

DrawText("HighText", false, " " + finalhigh , 0, High[0]+ (TickSize * Math.Abs( Offset)) ,Color.Blue, txtFont, StringAlignment.Near, Color.Transparent, Color.Transparent, 50);
DrawText("LowText", false, " " + finallow,0, Low[0] - (TickSize*Math.Abs( Offset)),Color.Red, txtFont, StringAlignment.Near, Color.Transparent, Color.Transparent, 50);

}

[NinjaTrader_JoshP]

Unfortunately I do not know. You will just have to play with it. You could just try trimming off the beginning part of the string instead.

[mrlogik]

mindset,

I recall reading something about string manipulation being slow.

It was recommended to me during my masters to use StringBuilder if string manipulation speed is critical.

I don't know to much to help you, but you can look in that direction.

hope this helps.

[Mindset]

thanks mrlogic I shall try and work through that and see if I can improve the speed - I did reload NT however and it improved considerably but there is definitely a drop off in performance now.

[NinjaTrader_Ray]

MeasureString() is a complete resource hog, I highly advise that you use it sparingly. In some of our system indicators such as BarTimer, this method is called once with the exception if the user changes the font in which case it needs to be called again.

[Mindset]

Hi Ray

Yes I found it in Bar timer strangely.
It seems using operands like "+" in strings causes lots of memory pressure or some such technical stuff that is not good.
I have got round it by doing the calculations separately

double l = Low[NBar] - TickSize;
string finallow = h.ToString(decstr).Substring(3);

I can't seem to get the hang of stringbuilder yet - I eagerly await the arrival of my book on C#.

[Mindset]

up the learning curve

I paid for a consultant to do some work for me (not this indicator) and this little bit of formatting popped up which I have used here - does away with a whole variable and much more elegant.

string finallow = String.Format("{0}",( Low[NBar]- TickSize)).Substring(chars);

[NinjaTrader_Bertrand]

Thanks for posting this snippet Mindset!