Quartz 实现画图片、写文字、画线、椭圆、矩形、棱形等。三

/*绘制图片

     NSString* imagePath = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];

     UIImage* myImageObj = [[UIImage alloc] initWithContentsOfFile:imagePath];

     //[myImageObj drawAtPoint:CGPointMake(0, 0)];

     [myImageObj drawInRect:CGRectMake(0, 0, 320, 480)];

 

     NSString *s = @"我的小狗";

 

     [s drawAtPoint:CGPointMake(100, 0) withFont:[UIFont systemFontOfSize:34.0]];

*/

     

   /*

     NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];

     UIImage *img = [UIImage imageWithContentsOfFile:path];

     CGImageRef image = img.CGImage;

     CGContextSaveGState(context);

     CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);

     CGContextDrawImage(context, touchRect, image);

     CGContextRestoreGState(context);

    */

   

     

     /*NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];

     UIImage *img = [UIImage imageWithContentsOfFile:path];

     CGImageRef image = img.CGImage;

     CGContextSaveGState(context);

 

     CGContextRotateCTM(context, M_PI);

     CGContextTranslateCTM(context, -img.size.width, -img.size.height);

 

     CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);

     CGContextDrawImage(context, touchRect, image);

     CGContextRestoreGState(context);*/

 

/*

     NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];

     UIImage *img = [UIImage imageWithContentsOfFile:path];

     CGImageRef image = img.CGImage;

     

     CGContextSaveGState(context);

 

     CGAffineTransform myAffine = CGAffineTransformMakeRotation(M_PI);

     myAffine = CGAffineTransformTranslate(myAffine, -img.size.width, -img.size.height);

     CGContextConcatCTM(context, myAffine);

 

     CGContextRotateCTM(context, M_PI);

     CGContextTranslateCTM(context, -img.size.width, -img.size.height);

 

     CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);

     CGContextDrawImage(context, touchRect, image);

     CGContextRestoreGState(context);

*/