iphone - 在目标 C 中保存之前更改图像

Question

我在空闲时间创建照片应用程序，但我想知道如何在将图像保存到照片文件夹之前设置图像的宽度和高度

@interface BIDViewController ()

@end

@implementation BIDViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)useCameraRoll:(id)sender {
    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeSavedPhotosAlbum])
    {
        UIImagePickerController *imagePiker = [[UIImagePickerController alloc]init];
        imagePiker.delegate = self;
        imagePiker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        imagePiker.mediaTypes = @[(NSString *) kUTTypeImage];
        imagePiker.allowsEditing =NO;
        [self presentViewController:imagePiker
                           animated:YES completion:nil];
        _newMedia = NO;
    }
}

- (IBAction)useCamera:(id)sender {
    if([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera])
    {
        UIImagePickerController *imagePicker = [[UIImagePickerController alloc]init];
        imagePicker.delegate =  self ;
        imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
        imagePicker.mediaTypes = @[(NSString *) kUTTypeImage];
        i
        imagePicker.allowsEditing = NO;
        [self presentViewController:imagePicker
                           animated:YES completion:nil];
        _newMedia = YES;
    }

}


-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSString *mediaType = info[UIImagePickerControllerMediaType];

    [self dismissViewControllerAnimated:YES completion:nil];

    if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
        UIImage *image = info[UIImagePickerControllerOriginalImage];

        _imageView.image = image;
        if (_newMedia)
            UIImageWriteToSavedPhotosAlbum(image,
                                           self,
                                           @selector(image:finishedSavingWithError:contextInfo:),
                                           nil);
    }
    else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])
    {
        // Code here to support video if enabled
    }
}

-(void)image:(UIImage *)image
finishedSavingWithError:(NSError *)error
 contextInfo:(void *)contextInfo
{
    if (error) {
        UIAlertView *alert = [[UIAlertView alloc]
                              initWithTitle: @"Save failed"
                              message: @"Failed to save image"
                              delegate: nil
                              cancelButtonTitle:@"OK"
                              otherButtonTitles:nil];
        [alert show];
    }
}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [self dismissViewControllerAnimated:YES completion:nil];
}



@end

Answer 1

UIImage在调用之前调整从选取器中检索到的对象的大小UIImageWriteToSavedPhotosAlbum()。这是一些用于轻松调整图像大小的好代码。