CGContextSetLineDash

Sets the pattern for dashed lines in a graphics context.

Declaration

extern void CGContextSetLineDash(CGContextRef c, CGFloat phase, const CGFloat *lengths, size_t count);

c:
The graphics context to modify.
phase:
A value that specifies how far into the dash pattern the line starts, in units of the user space. For example, passing a value of 3 means the line is drawn with the dash pattern starting at three units from its beginning. Passing a value of 0 draws a line starting with the beginning of a dash pattern.
lengths:
An array of values that specify the lengths of the painted segments and unpainted segments, respectively, of the dash pattern—or NULL for no dash pattern.
For example, passing an array with the values [2,3] sets a dash pattern that alternates between a 2-user-space-unit-long painted segment and a 3-user-space-unit-long unpainted segment. Passing the values [1,3,4,2] sets the pattern to a 1-unit painted segment, a 3-unit unpainted segment, a 4-unit painted segment, and a 2-unit unpainted segment.
count:
If the lengths parameter specifies an array, pass the number of elements in the array. Otherwise, pass 0.