保存一个 UIImage 并在 UIImageview 上重用它 [英] Save a UIImage and reused it on UIImageview

问题描述

我目前能够拍摄照片或从相机加载并在我的应用程序的 UIImageView 中放置图像，因为我希望能够有一个按钮来保存图像，因此当我重新加载应用程序时，图像是仍然在 UIImageView 中.

I currently have the ability to take a photo or load from the camera and place an image in the UIImageView in my app be i want the ability to have a button that will save the image so when i reload the app the image is still in the UIImageView.

我的虽然是一个按钮，一旦你加载它并在

My though was a button to save the image once you have loaded it and in the

-(void)viewDidLoad

有加载已保存图像的代码，但我不知道如何处理.

have the code to load the image that was saved but i don't know how to approach this.

任何帮助都会很棒.

推荐答案

您可以使用 UIImagePNGRepresentation 或 UIImageJPGRepresentation 将图像转换为 NSData，然后调用 NSData 的 writeToFile... 方法之一将数据保存到文件中.

You can convert images to NSData using either UIImagePNGRepresentation or UIImageJPGRepresentation, then save the data to file calling one of NSData's writeToFile... methods.

然后当你重新启动你的应用程序时，你可以通过调用[UIImage imageWithData:[NSData dataWithContentsOfFile:filePath]]

Then when you restart your application, you can get the image by calling [UIImage imageWithData:[NSData dataWithContentsOfFile:filePath]]

-- 编辑 --

保存图片

UIImage *image = ...;
NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image.png"];
[UIImagePNGRepresentation(image) writeToFile:cachedImagePath atomically:YES];

加载图片

NSString *cachedFolderPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
NSString *cachedImagePath = [cachedFolderPath stringByAppendingPathComponent:@"image.png"];
UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfFile:cachedImagePath]];

我使用了 NSCachesDirectory，因为我假设您不想备份此图像(通过 iCloud 或 iTunes).如果你这样做，那么你会想要使用 NSDocumentDirectory 代替.

I used NSCachesDirectory since I'm assuming you don't want to have this image backed up (either through iCloud or iTunes). If you do then you'd want to use NSDocumentDirectory instead.

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