IPhone development-resize, zoom in or out an image

To change the image size, the iphone has a clever method. The specific content is as follows:

First, create a new graphic environment (graphics context) and draw an image on it (note that the image size is the desired size ). The returned image is the image you want. The Code is as follows:

[Cpp] UIGraphicsBeginImageContext (CGSizeMake (480,320 ));
CGContextRef context = UIGraphicsGetCurrentContext ();
[Image drawInRect: CGRectMake (0, 0,480,320)];
UIImage * smallImage = UIGraphicsGetImageFromCurrentImageContext ();
UIGraphicsEndImageContext ();

From the column zcl316369