iOS动作扩展如何获取小图像

时间:2017-08-22 07:45:23

标签: ios objective-c

在系统照片库中,打开我的动作扩展程序,因为图像太大,扩展程序崩溃了,我怎样才能获得更小的图像?

我尝试使用以下代码,但它不起作用。

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

}];

1 个答案:

答案 0 :(得分:0)

在imageView上加载图像之前。首先调整它的大小。然后在imageView上加载已调整大小的图像。

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

调整图片大小数据:

-(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;
}