iOS动作扩展如何获取小图像

Question

在系统图片库中，打开我的动作扩展程序，因为图像太大，扩展程序崩溃了，我如何获得较小的图像？

我尝试使用以下代码，但无法正常工作。

NSDictionary * dict =@{NSItemProviderPreferredImageSizeKey:[NSValue valueWithCGSize:CGSizeMake(300, 300)]};
[itemProvider loadItemForTypeIdentifier:(NSString *)kUTTypeImage options:dict completionHandler:^(UIImage *image, NSError *error) {

}];

Answer 1

在将图像加载到imageView上之前。 首先调整它的大小。 然后将调整大小后的图像加载到imageView上。

UIImage *img = [UIImage imageWithData:selectedImgdata];
selectedImage = [self resizeImage:img];

调整图像数据大小：

-(UIImage *)resizeImage :(UIImage *)theImage
{
    if((theImage.size.width > 1024 && theImage.size.height > 768) || (theImage.size.width > 768 && theImage.size.height > 1024) || (theImage.size.width > 1024 && theImage.size.height < 768) || (theImage.size.height > 1024 && theImage.size.width < 768))
    {
        float newHeight,newWidth,oldWidth,oldHeight,scaleFactor;

        if(theImage.size.width > theImage.size.height)
        {
            oldWidth = theImage.size.width;
            scaleFactor = 1024 / oldWidth;

            newHeight = theImage.size.height * scaleFactor;
            newWidth = oldWidth * scaleFactor;
        }
        else
        {
            oldHeight = theImage.size.height;
            scaleFactor = 1024 / oldHeight;

            newWidth = theImage.size.width * scaleFactor;
            newHeight = oldHeight * scaleFactor;
        }

        UIGraphicsBeginImageContextWithOptions(CGSizeMake(newWidth, newHeight), NO, 1.0);
        [theImage drawInRect:CGRectMake(0, 0, newWidth, newHeight)];
        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return newImage;
    }
    return theImage;
}