How to get length of Ploy line Annotation

Dear Sir i'm using leadtools trial v18. sir How to get length of Ploy line Annotation.

The v18 is no longer available for evaluation, please download and evaluate v19.

Since you posted this under Dicom/Medical Imaging, I assume that you are using Medical Viewer.

You can use PolyRuler annotations instead of PolyLine annotations, which gives you the length of the polyruler object.
You can check this by running "Medical Viewer 32-bit" that you find under:

[LEADTOOLS 19]\Shortcuts\Medical Viewers\.NET Class Libraries\Medical Viewer\Main Medical Viewer Demo

As for the display of the poly ruler, you can remove the Ticks so its display will be almost similar to the PolyLine object display.

If above approach doesn't meet your requirement or you face problems applying PolyRuler object, send me the full details about the problem and which control you are using.

Thank you for reply,
i want free hand poly line. i want to draw zig zag style. this style does not cover in poly rular.free hand poly line does not display distance.

You can use the same approach for freehand because in the end it's a poly-line, but you will have to create the poly-ruler yourself after getting the points of the freehand polyline.
If you don't want to use this approach, you can calculate the length of the polyline by getting the points for the poly line and then calculate the distance between every two consecutive points using the distance formula, which is square root of [(delta X)2+(delta Y)2] as shown in the attached image.