攻略 10-4: 缩放图像 

-(void)configureDetailsWithImage:(UIImage *)image label:(NSString *)label showsButtons:(BOOL)showsButton
{
    self.imageView.image = image;
    self.detailDescriptionLabel.text = label;
    if (showsButton == NO)
    {
        self.selectImageButton.hidden = YES;
        self.clearImageButton.hidden = YES;
    }
    else if (showsButton == YES)
    {
        self.selectImageButton.hidden = NO;
        self.clearImageButton.hidden = NO;
    }
}
-(void)setMainImage:(UIImage *)image
{
    [self.filteredImages removeAllObjects];
    if (image != nil)
    {
        [self populateImageViewWithImage:image];
    }
    
    _mainImage = image;
    NSIndexPath *currentIndexPath = self.tableView.indexPathForSelectedRow;
    [self.tableView reloadData];
    [self.tableView selectRowAtIndexPath:currentIndexPath animated:YES scrollPosition:UITableViewScrollPositionTop];
}
 1 + (UIImage *)scaleImage:(UIImage *)image toSize:(CGSize)size
 2 {
 3     UIGraphicsBeginImageContext(size);
 4     [image drawInRect:CGRectMake(0, 0, size.width, size.height)];
 5     UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
 6     UIGraphicsEndImageContext();
 7     return scaledImage;
 8 }
 9 
10 + (UIImage *)aspectScaleImage:(UIImage *)image toSize:(CGSize)size
11 {
12     if (image.size.height < image.size.width)
13     {
14         float ratio = size.height / image.size.height;
15         CGSize newSize = CGSizeMake(image.size.width * ratio, size.height);
16         
17         UIGraphicsBeginImageContext(newSize);
18         [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
19     }
20     else
21     {
22         float ratio = size.width / image.size.width;
23         CGSize newSize = CGSizeMake(size.width, image.size.height*ratio);
24         
25         UIGraphicsBeginImageContext(newSize);
26         [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
27     }
28     UIImage *aspectScaledImage = UIGraphicsGetImageFromCurrentImageContext();
29     UIGraphicsEndImageContext();
30     return aspectScaledImage;
31 }
32 
33 + (UIImage *)aspectFillImage:(UIImage *)image toSize:(CGSize)size
34 {
35     UIGraphicsBeginImageContext(size);
36     if (image.size.height< image.size.width)
37     {
38         float ratio = size.height/image.size.height;
39         [image drawInRect:CGRectMake(0, 0, image.size.width*ratio, size.height)];
40     }
41     else
42     {
43         float ratio = size.width/image.size.width;
44         [image drawInRect:CGRectMake(0, 0, size.width, image.size.height*ratio)];
45     }
46     UIImage *aspectScaledImage = UIGraphicsGetImageFromCurrentImageContext();
47     UIGraphicsEndImageContext();
48     return aspectScaledImage;
49 }
 1 - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
 2 {
 3     if (self.mainImage != nil)
 4     {
 5         UIImage *image;
 6         NSString *label;
 7         BOOL showsButtons = NO;
 8         if (indexPath.row == 0)
 9         {
10             image = self.mainImage;
11             label = @"Select an Image to Display";
12             showsButtons = YES;
13         }
14         else if (indexPath.row == 1)
15         {
16             image = [MasterViewController scaleImage:self.mainImage toSize:self.detailViewController.imageView.frame.size];
17             label = @"Chosen Image Resized";
18         }
19         else if (indexPath.row == 2)
20         {
21             image = [MasterViewController aspectScaleImage:self.mainImage toSize:self.detailViewController.imageView.frame.size];
22             label = @"Chosen Image Scaled";
23         }
24         else if (indexPath.row == 3)
25         {
26             image = [self.filteredImages objectAtIndex:0];
27             CGSize contentSize = self.detailViewController.imageView.frame.size;
28             image = [MasterViewController aspectScaleImage:image toSize:contentSize];
29             label = @"Hue Adjustment";
30         }
31         else if (indexPath.row == 4)
32         {
33             image = [self.filteredImages objectAtIndex:1];
34             CGSize contentSize = self.detailViewController.imageView.frame.size;
35             image = [MasterViewController aspectScaleImage:image toSize:contentSize];
36             label = @"Straightening Filter";
37         }
38         else if (indexPath.row == 5)
39         {
40             image = [self.filteredImages objectAtIndex:2];
41             CGSize contentSize = self.detailViewController.imageView.frame.size;
42             image = [MasterViewController aspectScaleImage:image toSize:contentSize];
43             label = @"Series Filter";
44         }
45         [self.detailViewController configureDetailsWithImage:image label:label showsButtons:showsButtons];
46     }
47 }

 

posted @ 2016-06-12 17:57  FMDN  阅读(212)  评论(0)    收藏  举报