Rotating graphics for IOS development (86)

1 Preface
Use the CGAffineTransformMakeRotation/CGContextRotateCTM function to create an affine Rotation Transformation.

2. code example
ZYViewControllerView. m

 

[Plain]-(void) drawRect :( CGRect) rect {
/* Create the path first. Just the path handle .*/
CGMutablePathRef path = CGPathCreateMutable ();
/* Here are our rectangle boundaries */
CGRect rectangle = CGRectMake (10.0f, 10.0f, 200366f, 300366f );
/* Add the rectangle to the path */
CGPathAddRect (path, NULL, rectangle );
/* Get the handle to the current context */
CGContextRef currentContext = UIGraphicsGetCurrentContext ();
/* Save the state of the context to revert back to how it was at this state, later */
CGContextSaveGState (currentContext );
// Rotate 45 degrees clockwise
CGContextRotateCTM (currentContext, (45.0f * M_PI)/180.0f );
/* Add the path to the context */
CGContextAddPath (currentContext, path );
/* Set the fill color to cornflower blue */
[[UIColor colorWithRed: 0.20f green: 0.60f blue: 0.80f alpha: 1.0f] setFill];
/* Set the stroke color to brown */
[[UIColor brownColor] setStroke];
/* Set the line width (for the stroke) to 5 */
CGContextSetLineWidth (currentContext, 5.0f );
/* Stroke and fill the path on the context */
CGContextDrawPath (currentContext, kCGPathFillStroke );
/* Dispose of the path */
CGPathRelease (path );
/* Restore the state of the context */
CGContextRestoreGState (currentContext );
}