将图像数据保存在图像视图中

Question

在应用程序中，我创建了一个图像视图，其中包含从手机库中选择或由相机拍摄的图像。但是当我回到前一个场景时，选择的图像消失了。我希望它保存在图像视图中并有一个清除按钮来删除它。相机功能有效，但图像不会停留在图像视图中。

相机功能： .h 文件

@interface FMEImageView : UIViewController <UINavigationControllerDelegate, UIImagePickerControllerDelegate> {
IBOutlet UIImageView *ImageView;
UIImagePickerController *picker;

UIImage *image;

}

- (IBAction)Takephoto:(id)sender;
- (IBAction)Chosenphoto:(id)sender;
@end

.m 文件

- (IBAction)Takephoto:(id)sender{
picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
[picker setSourceType:UIImagePickerControllerSourceTypeCamera];
[self presentViewController:picker animated:YES completion:NULL];


}

- (IBAction)Chosenphoto:(id)sender{
picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
[picker setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
[self presentViewController:picker animated:YES completion:NULL];


 }

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{

image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
[ImageView setImage:image];
[self dismissViewControllerAnimated:YES completion:NULL];
}

- (void) imagePickerControllerDidCancel:(UIImagePickerController *)picker {
[self dismissViewControllerAnimated:YES completion:NULL];
}

Answer 1

我认为，您必须将图像保存到应用程序的文档目录中。

获取图像数据。

NSData *imgData = UIImagePNGRepresentation(image);

将其写入文档目录。

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
NSString *documentsPath = [paths objectAtIndex:0]; 
NSString *filePath = [documentsPath stringByAppendingPathComponent:@"image.png"];//Choose name for the image. 

[imgData writeToFile:filePath atomically:YES]; //Write the file

获取数据并将其显示在 imageView 上。

再次，获取文件路径。

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
NSString *documentsPath = [paths objectAtIndex:0]; 
NSString *filePath = [documentsPath stringByAppendingPathComponent:@"image.png"];//Name you have given    

NSData *imgData = [NSData dataWithContentsOfFile:filePath];
UIImage *image = [UIImage imageWithData:imgData];

imageView.image = image;

最好做个函数来获取文档目录的路径。

希望对你有帮助。

Answer 2

您可能每次都在使用新实例。初始化后使用相同的实例。