[英]iOS : How to handle images?
I'm making a photo managing app. 我正在制作照片管理应用。 I have created a class called photo, which has the name of the photo, notes on the photo, and the image. 我创建了一个名为photo的类,它有照片的名称,照片上的注释和图像。 I know how to set the name and notes - they're both NSStrings, but what data type should I use for my image? 我知道如何设置名称和注释 - 它们都是NSStrings,但我应该为我的图像使用什么数据类型?
At the moment, I'm using NSData, is that correct? 目前,我正在使用NSData,这是正确的吗?
Edit 编辑
Apparently, NSData is right. 显然,NSData是对的。 So, how should I get an image from a UIImage into the NSData object and back again? 那么,我应该如何将UIImage中的图像转换为NSData对象并再次返回?
Data from UIImage: 来自UIImage的数据:
NSData *imageData = UIImagePNGRepresentation(image);
Alternatively, UIImage from data: 或者,来自数据的UIImage:
UIImage *image = [UIImage imageWithData:imageData];
You can store your image as an UIImage or NSData 您可以将图像存储为UIImage或NSData
You can simply get one from another: 你可以简单地从另一个:
NSData *data = UIImagePNGRepresentation(image);
UIImage *image=[UIImage imageWithData:data];
In case you need the image for presenting it's better practice to hold an UIImage
instance in youre object transferring it to/from NSData
when you need to save it or get it either from the net or the disk. 如果您需要图像来呈现它,那么当您需要保存或从网络或磁盘获取UIImage
实例时,将对象传输到NSData
或从NSData
传输它是更好的做法。 If youre case is more like file manager then photo viewer, then this answer is not aplicable. 如果你的情况更像文件管理器然后照片查看器,那么这个答案是不适用的。 Anyway the transfering routines were provided to you by previous answer. 无论如何,转移程序是通过以前的答案提供给你的。
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