UIImageView显示处理（圆角，变灰,uiimage放大）

转自：http://blog.csdn.net/cerastes/article/details/31736737

1.UIImageView圆角

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CALayer *l = [cell.imgAvatarImage layer];     

[l setMasksToBounds:YES];  

[l setCornerRadius:6.0];  

2.UIImageView显示圆形

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UIImageView *imageView1 = [[UIImageViewalloc] initWithImage:[UIImageimageNamed:@"image.png"]];  

  

imageView1.frame = CGRectMake(60,100, 100, 100);  

  

imageView1.layer.masksToBounds =YES;  

  

imageView1.layer.cornerRadius =50;  

  

[self.view addSubview:imageView1];  

3.UIImageView变灰效果

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+ (UIImage*)getGrayImage:(UIImage*)sourceImage  

{  

    int width = sourceImage.size.width;  

    int height = sourceImage.size.height;  

      

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();  

    CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);  

    CGColorSpaceRelease(colorSpace);  

      

    if (context == NULL) {  

        return nil;  

    }  

      

    CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);  

    CGImageRef grayImageRef = CGBitmapContextCreateImage(context);  

    UIImage *grayImage = [UIImage imageWithCGImage:grayImageRef];  

    CGContextRelease(context);  

    CGImageRelease(grayImageRef);  

      

    return grayImage;  

}  

4 UIImage设置显示大小

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- (UIImage *)scaleToSize:(UIImage *)img size:(CGSize)size{  

     UIGraphicsBeginImageContext(size);  

         [img drawInRect:CGRectMake(0, 0, size.width, size.height)];  

        UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();  

        // 使当前的context出堆栈  

        UIGraphicsEndImageContext();  

    // 返回新的改变大小后的图片  

    return scaledImage;  

}