UIImage图片处理：缩放、设定大小、存储 (转载)

//1.等比率缩放
- (UIImage *)scaleImage:(UIImage *)image toScale:(float)scaleSize{
UIGraphicsBeginImageContext(CGSizeMake(image.size.width * scaleSize, image.size.height * scaleSize);
[image drawInRect:CGRectMake(0, 0, image.size.width * scaleSize, image.size.height * scaleSize)];
UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return scaledImage;
}

//2.自定长宽
- (UIImage *)reSizeImage:(UIImage *)image toSize:(CGSize)reSize{
UIGraphicsBeginImageContext(CGSizeMake(reSize.width, reSize.height));
[image drawInRect:CGRectMake(0, 0, reSize.width, reSize.height)];
UIImage *reSizeImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return reSizeImage;
}

//3.处理某个特定View
//只要是继承UIView的object 都可以处理
//必须先import QuzrtzCore.framework
-(UIImage*)captureView:(UIView *)theView{
CGRect rect = theView.frame;
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[theView.layer renderInContext:context];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}

//4.储存图片
//储存图片这里分成储存到app的文件里, 储存到手机的图片库里
// 储存到app的文件里
NSString *path = [[NSHomeDirectory()stringByAppendingPathComponent:@"Documents"]stringByAppendingPathComponent:@"image.png"];
[UIImagePNGRepresentation(image) writeToFile:pathatomically:YES];