The Ruler mark enables the end user to create a line that displays its measurement.

Edit Mode

In Edit mode, end users create this mark as follows:

1. Click the Ruler button.
2. Click where the line begins and drag it to the end of the line.
3. Release the mouse button to complete the line.
4. Right-click the mark after it is created to activate the popup Edit menu. 

Ruler Length Measuring Modes

ImageGear provides two different length measuring modes for Ruler and PolyRuler annotations – Absolute and Relative, which can be changed using ImGearARTPage.AspectKind property.

• Absolute – In this mode, a change to the resolution of the underlying image will not affect the physical measurements of your marks (such as length of the ruler or poly-ruler) on the screen. The physical measurements of your marks on the screen are absolute.

If the physical measurements of your marks need to reflect the changes to the resolution of the underlying image, you should work with pages and marks in Relative mode instead.

• Relative – In this mode, a change to the resolution of the underlying image will affect the physical measurements of your marks (such as length of the ruler or poly-ruler) on the screen. The physical measurements of your marks on the screen are relative to the resolution of the underlying image.

If the physical measurements of your marks need to remain constant regardless of the resolution of the underlying image, you should work with pages and marks in Absolute mode instead.