How to convert all image format into .png format?

问题

I am making a small application where I am receiving images from web-service. I am getting the image url. And the format of images is different different like .jpg,.gif,.png etc. And I want to save these images into my sandbox and later on show it into image view.

To do this I am giving a self name and gave the extension to .png. But at the time of retrieving the .png images are shown but different one's are not shown. So can you give me any idea how to convert all images to .png format or any other approach to do this?

回答1:

after you retrieve your images/url save them this way:

NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:savedImagePath atomically:YES];

回答2:

Would it not be easier if you use an image library like SDWebImage which handles all the asynchronous image downloading and caching of the image onto your device?

https://github.com/rs/SDWebImage

Then you can do something like:

[myImageView setImageWithURL:[NSURL URLWithString:@"http://www.domain.com/path/to/image.jpg"]
                   placeholderImage:[UIImage imageNamed:@"placeholder.png"]];

来源：https://stackoverflow.com/questions/12597710/how-to-convert-all-image-format-into-png-format