Question

我尝试在图片视图中加载相册中的图片，然后点击按钮调整大小，然后按另一个按钮以使用新尺寸保存图片。

Evrything运行良好，但保存的图像与原始图像大小相同。

这是我到目前为止所做的：

    - (IBAction)chooseImage:(id)sender
{
    self.imagePicker = [[UIImagePickerController alloc] init];
    self.imagePicker.delegate = self;
    [self.imagePicker setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
    [self presentViewController:self.imagePicker animated:YES completion:nil];
    }

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    self.chosenImage = info[UIImagePickerControllerOriginalImage];
    [self.imageView setImage:self.chosenImage];
    [self dismissViewControllerAnimated:YES completion:nil];
}

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

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


- (IBAction)reSize:(id)sender

{
    CGRect newFrame = CGRectMake(20, 49, 280, 200);
    [UIView animateWithDuration:0.25f
                     animations:^{
                         self.imageView.frame = newFrame;
                     }];
}

- (IBAction)saveImage:(id)sender
{
       UIImageWriteToSavedPhotosAlbum(_chosenImage, self, nil, nil);
}


@end

Answer 1

UIImageView* image = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"whatever"]];

CGSize size = image.bounds.size;
UIGraphicsBeginImageContext(size);

CGContextRef context = UIGraphicsGetCurrentContext();
CGAffineTransform flipVertical = CGAffineTransformMake(
        1, 0, 0, -1, 0, size.height
);
CGContextConcatCTM(context, flipVertical);  
CGContextDrawImage(context, image.bounds, image.image.CGImage);
UIImage *resized = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

UIImageWriteToSavedPhotosAlbum(resized, self, nil, nil);

将image替换为您要绘制的已调整大小的图像视图。

Answer 2

您可以通过创建UIImage类别来重用此调整大小代码，还有一个现有的良好UIImage类别可以进行图像调整大小，很少有其他东西可以找到它的用法here。

调整uiimage中的图像大小并将其保存为相册的新大小

2 个答案: