将UIImage转换为NSData并使用核心数据保存
我有一个UIImageView其图像通过UIImagePicker设置
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{ [picker dismissViewControllerAnimated:YES completion:nil]; self.gImage.image = [info objectForKey:@"UIImagePickerControllerOriginalImage"]; }
我“尝试”将此图像转换为NSData并使用核心数据保存：
NSData *imageData = UIImagePNGRepresentation(self.gImage.image); NSString *savedData = [[NSString alloc]initWithData:imageData encoding:NSUTF8StringEncoding]; //am is a pointer to my entities class. imageData is just a NSString attribute am.imageData = savedData; NSError *error; if (![self.managedObjectContext save:&error]) { //Handle Error } else { [self dismissViewControllerAnimated:YES completion:nil]; }
然后我尝试将图像加载到一个单独的文件中：
self.cell.gImage.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:self.myEntity.imageData]]];
我不明白为什么这不起作用。 任何帮助是极大的赞赏！
您可以将UIImage转换为NSData，如下所示：
如果PNG图像
UIImage *image = [UIImage imageNamed:@"imageName.png"]; NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(image)];
如果是JPG图片
UIImage *image = [UIImage imageNamed:@"imageName.jpg"]; NSData *imageData = UIImageJPEGRepresentation(image, 1.0);
您可以将它存储在CoreData中（这是一个可能有用的解决方案）：
[newManagedObject setValue:imageData forKey:@"image"];
您可以像这样从CoreData加载数据：
NSManagedObject *selectedObject = [[self yourFetchCOntroller] objectAtIndexPath:indexPath]; UIImage *image = [UIImage imageWithData:[selectedObject valueForKey:@"image"]]; // Set the image to your image view yourimageView.image = image;
对于它的刚刚：
UIImage到NSData
imageData = UIImagePNGRepresentation(image)
用于存储在数据库:::
NSInteger RandomIndex = arc4random() % 1000; NSString *randomImageName =[NSString stringWithFormat:@"Image%i.png",RandomIndex]; NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:randomImageName]; if ([[NSFileManager defaultManager] fileExistsAtPath:savedImagePath]) { [[NSFileManager defaultManager] removeItemAtPath:savedImagePath error:nil]; NSLog(@"file removed from path"); } NSLog(@"Saved Image Path : %@",savedImagePath); NSData* imageData = UIImagePNGRepresentation (image1 ); [imageData writeToFile:savedImagePath atomically:YES]; //am is a pointer to my entities class. imageData is just a NSString attribute am.imageData = randomImageName;
从数据库中获取该图像时，可以编写以下代码…
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:randomImageName]; NSData *myData = [NSData dataWithContentsOfFile:savedImagePath]; UIImage *selectedImage = [UIImage imageWithData:myData];
我认为这对你很有帮助。
在Mac OS上，您可以通过勾选模型中属性的Transformable框，而不是选择特定的变换器，并将UIImage直接分配给属性，让Core Data为您处理。
我不确定它是否适用于iOS，但它可能值得一试。
要将图像转换为NSData，请尝试以下代码…
UIImage *image = [UIImage imageNamed:@"imageName.png"]; NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(image)];
让我知道它是否正常工作.. !!!
快乐的编码!!!!
尝试使用此代码保存图像数据
保存：
NSManagedObjectContext *context = [self managedObjectContext]; newsObj = [NSEntityDescription insertNewObjectForEntityForName:@"Event" inManagedObjectContext:context]; NSData *imageData = UIImagePNGRepresentation(self.gImage.image); [newsObj setValue:imageData forKey:@"imgPng"]; NSError *error; @try{ if (managedObjectContext != nil) { if (![managedObjectContext save:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); } } }@catch (NSException *exception) { NSLog(@"inside exception"); }
要回复试试这个：
NSManagedObjectContext *context = [self managedObjectContext]; NSFetchRequest * fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity1 = [NSEntityDescription entityForName:@"Event" inManagedObjectContext:context]; [fetchRequest setEntity:entity1]; NSError *error; NSArray * array = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error]; if (array == nil) { NSLog(@"Testing: No results found"); }else { NSLog(@"Testing: %d Results found.", [array count]); } NSData * dataBytes = [[array objectAtIndex:0] imgPng];; image = [UIImage imageWithData:dataBytes]; [fetchRequest release]; } @catch (NSException *exception) { NSLog(@"inside exception"); }
此代码将您的图像数据保存到filedata中，您可以在任何地方使用它
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image1 editingInfo:(NSDictionary *)editingInfo { { CGSize destinationSize = CGSizeMake(170,170); UIGraphicsBeginImageContext(destinationSize); [image1 drawInRect:CGRectMake(0,0,destinationSize.width,destinationSize.height)]; UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); NsData *filedata = UIImagePNGRepresentation(newImage); [picker dismissModalViewControllerAnimated:YES]; } }
这是我所做的以及它存储到nsdata的工作。
[productTypeSub setValue:[[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:url]] forKey:@"imgSmall"];
并使用此代码加载到图像
ImgProductType.image= [[UIImage alloc] initWithData:productTypeSub.imgSmall];