Gets the current value of the page's stroking color.
grayStroke() is valid only when the page's stroking color space is HPDF_CS_DEVICE_GRAY.
when succeed, it returns the current value of the page's stroking color. Otherwise it returns 0.
See Implementation
Gets the current value of the page's stroking color.
grayStroke() is valid only when the page's stroking color space is HPDF_CS_DEVICE_GRAY.