+ (UIImage *)getPicZoomImage:(UIImage *)image {
UIImage *img = image;
int h = img.size.height;
int w = img.size.width;
if(h <= PicAfterZoomWidth && w <= PicAfterZoomHeight)
{
image = img;
}
else
{
float b = (float)PicAfterZoomWidth/w < (float)PicAfterZoomHeight/h ? (float)PicAfterZoomWidth/w : (float)PicAfterZoomHeight/h;
CGSize itemSize = CGSizeMake(b*w, b*h);
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0, 0, b*w, b*h);
[img drawInRect:imageRect];
img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
return img;
}
=============== ( two )把图片 圆角 化==================================
static void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth,
float ovalHeight)
{
float fw, fh;
if (ovalWidth == 0 || ovalHeight == 0) {
CGContextAddRect(context, rect);
return;
}
CGContextSaveGState(context);
CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGContextScaleCTM(context, ovalWidth, ovalHeight);
fw = CGRectGetWidth(rect) / ovalWidth;
fh = CGRectGetHeight(rect) / ovalHeight;
CGContextMoveToPoint(context, fw, fh/2); // Start at lower right corner
CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1); // Top right corner
CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); // Top left corner
CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); // Lower left corner
CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // Back to lower right
CGContextClosePath(context);
CGContextRestoreGState(context);
}
+ (id) createRoundedRectImage:(UIImage*)image size:(CGSize)size
{
// the size of CGContextRef
int w = size.width;
int h = size.height;
UIImage *img = image;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace,kCGImageAlphaPremultipliedFirst);
CGRect rect = CGRectMake(0, 0, w, h);
CGContextBeginPath(context);
addRoundedRectToPath(context, rect, 10, 10);
CGContextClosePath(context);
CGContextClip(context);
CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);
CGImageRef imageMasked = CGBitmapContextCreateImage(context);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
return [UIImage imageWithCGImage:imageMasked];
}
=============== (Three)给图片 添加阴影==================================
請先添加库 import QuartzCore.framework
然后要导入头文件 #import <QuartzCore/QuartzCore.h>
[[myView layer] setShadowOffset:CGSizeMake(5, 5)]; //设置阴影起点位置
[[myView layer] setShadowRadius:6]; //设置阴影扩散程度
[[myView layer] setShadowOpacity:1]; //设置阴影透明度
[[myView layer] setShadowColor:[UIColor blueColor].CGColor]; //设置阴影颜色
========== (Four) UIImage 图像 旋转==================================
- (UIImage *)imageRotatedByRadians:(CGFloat)radians
{
return [self imageRotatedByDegrees:radians * 180/M_PI];
}
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees
{
// calculate the size of the rotated view's containing box for our drawing space
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width,self.size.height)];
CGAffineTransform t = CGAffineTransformMakeRotation(degrees * M_PI / 180);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
[rotatedViewBox release];
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, degrees * M_PI / 180);
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2,self.size.width, self.size.height), [self CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
图像旋转更多请看：http://www.catamount.com/blog/1015/uiimage-extensions-for-cutting-scaling-and-rotating-uiimages/
