How do I draw an NSString at an angle?

问题:

Is there a set of string attributes I can specify that will draw the text at an angle when I call:

[label drawAtPoint:textStart withAttributes:attributes];

回答1:

Here's an example that uses a transform to rotate the drawing context. Essentially it's just like setting a color or shadow, just make sure to use -concat instead of -set.

CGFloat rotateDeg = 4.0f;
NSAffineTransform *rotate = [[NSAffineTransform alloc] init];

[rotate rotateByDegrees:rotateDeg];
[rotate concat];

// Lock focus if needed and draw strings, images here.

[rotate release];

回答2:

NSString itself doesn't have rotation, but you can rotate the context. The string will always be drawn "horizontally" as far as the coordinate space goes, but what actual direction that corresponds to depends on the context. Just use NSAffineTransform to spin it as needed.