iOS使用代码截图详解手机开发

 
 
    // 从view上截图   
    - (UIImage *)getImage {   
           
        UIGraphicsBeginImageContextWithOptions(CGSizeMake(150, 150), NO, 1.0);  //NO，YES 控制是否透明   
        [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];   
        UIImage *image = UIGraphicsGetImageFromCurrentImageContext();   
        UIGraphicsEndImageContext();   
        // 生成后的image   
           
        return image;   
    }   
       
    // 根据给定得图片，从其指定区域截取一张新得图片   
    -(UIImage *)getImageFromImage{   
        //大图bigImage   
        //定义myImageRect，截图的区域   
        CGRect myImageRect = CGRectMake(70, 10, 150, 150);   
        UIImage* bigImage= [UIImage imageNamed:@"mm.jpg"];   
        CGImageRef imageRef = bigImage.CGImage;   
        CGImageRef subImageRef = CGImageCreateWithImageInRect(imageRef, myImageRect);   
        CGSize size;   
        size.width = 150;   
        size.height = 150;   
        UIGraphicsBeginImageContext(size);   
        CGContextRef context = UIGraphicsGetCurrentContext();   
        CGContextDrawImage(context, myImageRect, subImageRef);   
        UIImage* smallImage = [UIImage imageWithCGImage:subImageRef];   
        UIGraphicsEndImageContext();   
        return smallImage;   
    }