《《iPhone UIImage扩展方法》.doc

iPhone UIImage扩展方法,支持放大和旋转 #import Foundation/Foundation.h@interface UIImage (CS_Extensions)- (UIImage *)imageAtRect:(CGRect)rect;- (UIImage *)imageByScalingProportionallyToMinimumSize:(CGSize)targetSize;- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize;- (UIImage *)imageByScalingToSize:(CGSize)targetSize;- (UIImage *)imageRotatedByRadians:(CGFloat)radians;- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees;@end; //// UIImage-Extensions.m//// Created by Hardy Macia on 7/1/09.// Copyright 2009 Catamount Software. All rights reserved.//#import UIImage-Extensions.hCGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/M_PI;};@implementation UIImage (CS_Extensions)-(UIImage *)imageAtRect:(CGRect)rect{CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], rect);UIImage* subImage = [UIImage imageWithCGImage: imageRef];CGImageRelease(imageRef);return subImage;}- (UIImage *)imageByScalingProportionallyToMinimumSize:(CGSize)targetSize {UIImage *sourceImage = self;UIImage *newImage = nil;CGSize imageSize = sourceImage.size;CGFloat width = imageSize.width;CGFloat height = imageSize.height;CGFloat targetWidth = targetSize.width;CGFloat targetHeight = targetSize.height;CGFloat scaleFactor = 0.0;CGFloat scaledWidth = targetWidth;CGFloat scaledHeight = targetHeight;CGPoint thumbnailPoint = CGPointMake(0.0,0.0);if (CGSizeEqualToSize(imageSize, targetSize) == NO) {CGFloat widthFactor = targetWidth / width;CGFloat heightFactor = targetHeight / height;if (widthFactor heightFactor)scaleFactor = widthFactor;elsescaleFactor = heightFactor;scaledWidth = width * scaleFactor;scaledHeight = height * scaleFactor;// center the imageif (widthFactor heightFactor) {thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;} else if (widthFactor heightFactor) {thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;}}// th