UIImageView变灰

1.UIImageView圆角

1. CALayer *l = [cell.imgAvatarImage layer];
2. [l setMasksToBounds:YES];
3. [l setCornerRadius:6.0];

2.UIImageView显示圆形

1. UIImageView *imageView1 = [[UIImageViewalloc] initWithImage:[UIImageimageNamed:@"image.png"]];
2. imageView1.frame = CGRectMake(60,100, 100, 100);
3. imageView1.layer.masksToBounds =YES;
4. imageView1.layer.cornerRadius =50;
5. [self.view addSubview:imageView1];

3.UIImageView变灰效果

1. + (UIImage*)getGrayImage:(UIImage*)sourceImage
2. {
3. int width = sourceImage.size.width;
4. int height = sourceImage.size.height;
5. CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
6. CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);
7. CGColorSpaceRelease(colorSpace);
8. if (context == NULL) {
9. return nil;
10. }
11. CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);
12. CGImageRef grayImageRef = CGBitmapContextCreateImage(context);
13. UIImage *grayImage = [UIImage imageWithCGImage:grayImageRef];
14. CGContextRelease(context);
15. CGImageRelease(grayImageRef);
16. return grayImage;
17. }

4 UIImage设置显示大小

1. - (UIImage *)scaleToSize:(UIImage *)img size:(CGSize)size{
2. UIGraphicsBeginImageContext(size);
3. [img drawInRect:CGRectMake(0, 0, size.width, size.height)];
4. UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
5. // 使当前的context出堆栈
6. UIGraphicsEndImageContext();
7. // 返回新的改变大小后的图片
8. return scaledImage;
9. }