我使用uiimagepickercontroller有一个有趣的小问题，并想知道是否有人对可能发生的事情有任何见解。用户可以使用相机拍照或从照片库中选择，直到奶牛连续多次回家。我的问题在于允许用户恢复到应用随附的原始图像。这是流程：
恢复原始图像当应用程序关闭然后再次打开时，它可以正常工作。有时，如果您在应用程序中导航到其他视图，然后返回到他们刚刚添加了自己的图像的详细视图，它将起作用。为何延迟？我已经搜索了两个星期，但没有发现任何类似于我的问题或任何有任何帮助的解决方案（比如重新加载图像所在的标题视图）。有什么想法吗？
此外，我已经弄清楚如何使用文档将图像保存到iCloud，但无法弄清楚如何检索它们，因此没有代码。这是完全不同的问题。即使没有该代码，似乎也会发生同样的事情。
感谢您花时间看看这个！
以下是一些代码：
-(void)bookImageTapped:(UIGestureRecognizer *)gesture
{
URBAlertView *changeImageAlertView = [[URBAlertView alloc] initWithTitle:@"Add A New Book Cover Image" message:nil cancelButtonTitle:@"Cancel" otherButtonTitles:@"Use Camera", @"Open Gallery", @"Use Original Photo", nil];
[changeImageAlertView setHandlerBlock:^(NSInteger buttonIndex, URBAlertView *alertView) {
[self checkPermission];
if (PHAuthorizationStatusAuthorized)
{
if(buttonIndex == 0)
{
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
UIImagePickerController *pickerController = [[UIImagePickerController alloc] init];
pickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
pickerController.delegate = self;
pickerController.allowsEditing = NO;
pickerController.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
[self presentViewController:pickerController animated:YES completion:nil];
}];
[alertView hide];
}
else
{
NSLog(@"Camera not available");
[alertView hide];
}
}
else if (buttonIndex == 1)
{
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
UIImagePickerController *pickerController = [[UIImagePickerController alloc] init];
pickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
pickerController.delegate = self;
pickerController.allowsEditing = NO;
pickerController.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
[self presentViewController:pickerController animated:YES completion:nil];
}];
[alertView hide];
}
else if (buttonIndex == 2)
{
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
[self restoreOriginalPhoto];
}];
[alertView hide];
}
else
{
NSLog(@"button 2 cancel");
[alertView hide];
}
}
}];
[changeImageAlertView show];
}
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(nonnull NSDictionary<NSString *,id> *)info
{
[picker dismissViewControllerAnimated:YES completion:nil];
_book.largeBookImage = [info objectForKey:UIImagePickerControllerOriginalImage];
_book.largeBookImage = [self scaleImage:_book.largeBookImage toSize:CGSizeMake(120, 168)];
_bookImageView.image = _book.largeBookImage;
_book.wasNewImageAdded = YES;
_book.originalImageUsed = NO;
NSString * documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
[self saveImage:_book.largeBookImage withFileName:_book.bookImageID ofType:@"jpg" inDirectory:documentsDirectory];
}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
[picker dismissViewControllerAnimated:YES completion:nil];
}
-(void)saveImage:(UIImage *)image withFileName:(NSString *)imageName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath
{
if ([[extension lowercaseString] isEqualToString:@"png"])
{
[UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]] options:NSAtomicWrite error:nil];
//Create a URL to the local file
NSURL *resourceURL = [NSURL fileURLWithPath:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]]];
if (resourceURL)
{
CKAsset *asset = [[CKAsset alloc] initWithFileURL:resourceURL];
//create a record object
CKRecord *bookCover = [[CKRecord alloc] initWithRecordType:@"Bookcover"];
//set the record's fields
bookCover[@"title"] = _book.title;
bookCover[@"bookImage"] = asset;
/* TO SAVE A RECORD */
//get the public database
CKContainer *appContainer = [CKContainer defaultContainer];
CKDatabase *publicDatabase = [appContainer publicCloudDatabase];
[publicDatabase saveRecord:bookCover completionHandler:^(CKRecord *bookCover, NSError *error) {
if (error)
{
//insert error handling
return;
}
//insert succesfully saved record code
NSLog(@"png record saved after using picker!");
}];
}
}
else if ([[extension lowercaseString] isEqualToString:@"jpg"] || [[extension lowercaseString] isEqualToString:@"jpeg"])
{
[UIImageJPEGRepresentation(image, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]] options:NSAtomicWrite error:nil];
//Create a URL to the local file
NSURL *resourceURL = [NSURL fileURLWithPath:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]]];
if (resourceURL)
{
CKAsset *asset = [[CKAsset alloc] initWithFileURL:resourceURL];
//create a record object
CKRecord *bookCover = [[CKRecord alloc] initWithRecordType:@"Bookcover"];
//set the record's fields
bookCover[@"title"] = _book.title;
bookCover[@"bookImage"] = asset;
/* TO SAVE A RECORD */
//get the public database
CKContainer *appContainer = [CKContainer defaultContainer];
CKDatabase *publicDatabase = [appContainer publicCloudDatabase];
[publicDatabase saveRecord:bookCover completionHandler:^(CKRecord *bookCover, NSError *error) {
if (error)
{
//insert error handling
return;
}
//insert succesfully saved record code
NSLog(@"jpg record saved after using picker!");
}];
}
}
else
{
NSLog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", extension);
}
}
- (UIImage *) scaleImage:(UIImage*)image toSize:(CGSize)newSize
{
UIGraphicsBeginImageContextWithOptions(newSize, NO, 0.0);
[image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
-(void)restoreOriginalPhoto
{
NSLog(@"restore photo called");
_book.originalImageUsed = YES;
_book.wasNewImageAdded = NO;
_bookImageView.image = _book.largeBookImage;
NSString * documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
[self saveImage:_book.largeBookImage withFileName:_book.bookImageID ofType:@"jpg" inDirectory:documentsDirectory];
}
以下是带有imageview的标题视图：
-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
_headerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, tableView.frame.size.width, 26)];
_headerView.backgroundColor = [UIColor colorWithRed:8/255.0 green:46/255.0 blue:46/255.0 alpha:0.8];
if (section == 0)
{
_headerView.backgroundColor = [UIColor whiteColor];
_bookImageView = [[UIImageView alloc] initWithFrame:CGRectMake((tableView.frame.size.width - 120)/2, 6, 120, 168)];
_bookImageView.contentMode = UIViewContentModeScaleAspectFit;
if (_book.wasNewImageAdded)
{
NSString * documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
UIImage * image = [self loadImageWithFileName:_book.bookImageID ofType:@"jpg" inDirectory:documentsDirectory];
_bookImageView.image = image;
}
else
{
_bookImageView.image = _book.largeBookImage;
}
if(_book.originalImageUsed)
{
NSString * documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
UIImage * image = [self loadImageWithFileName:_book.bookImageID ofType:@"jpg" inDirectory:documentsDirectory];
_bookImageView.image = image;
}
UITapGestureRecognizer *bookImageTouched = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(bookImageTapped:)];
bookImageTouched.numberOfTapsRequired = 1;
[_bookImageView addGestureRecognizer:bookImageTouched];
_bookImageView.userInteractionEnabled = YES;
[_headerView addSubview:_bookImageView];
}
答案 0 :(得分：0)
我终于明白了！似乎我把xcode与我的属性名称混淆了。最后，代码最终变得更加简单。
在didFinishPickingMediaWithInfo中，我创建了一个UIImage，然后将其设置为bookImageView.image。后来，当我希望能够将图像更新回原始图像时，我可以调用捆绑资产_book.largeBookImage。瞧！图像能够立即更新。
最相关的代码发布在下面。
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(nonnull NSDictionary<NSString *,id> *)info
{
[picker dismissViewControllerAnimated:YES completion:nil];
_chosenImage = [[UIImage alloc] init];
_chosenImage = [info objectForKey:UIImagePickerControllerOriginalImage];
_bookImageView.image = _chosenImage;
_book.wasNewImageAdded = YES;
_book.originalImageUsed = NO;
NSString * documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
[self saveImage:_chosenImage withFileName:_book.bookImageID ofType:@"jpg" inDirectory:documentsDirectory];
}
-(void)saveImage:(UIImage *)image withFileName:(NSString *)imageName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath
{
if ([[extension lowercaseString] isEqualToString:@"png"])
{
[UIImagePNGRepresentation(image) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"png"]] options:NSAtomicWrite error:nil];
[self.tableView reloadData];
}
else if ([[extension lowercaseString] isEqualToString:@"jpg"] || [[extension lowercaseString] isEqualToString:@"jpeg"])
{
[UIImageJPEGRepresentation(image, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@", imageName, @"jpg"]] options:NSAtomicWrite error:nil];
[self.tableView reloadData];
}
else
{
//NSLog(@"Image Save Failed\nExtension: (%@) is not recognized, use (PNG/JPG)", extension);
}
}
-(void)restoreOriginalPhoto
{
_book.originalImageUsed = YES;
_book.wasNewImageAdded = NO;
_bookImageView.image = _book.largeBookImage;
_backgroundImage.image = _book.largeBookImage;
}
-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
if (section == 0)
{
_bookImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 120, 168)];
_bookImageView.contentMode = UIViewContentModeScaleAspectFit;
_bookImageView.clipsToBounds = YES;
_bookImageView.layer.cornerRadius = 10.0f;
if (_book.wasNewImageAdded)
{
NSString * documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
UIImage * image = [self loadImageWithFileName:_book.bookImageID ofType:@"jpg" inDirectory:documentsDirectory];
_bookImageView.image = image;
}
else
{
_bookImageView.image = _book.largeBookImage;
}
if(_book.originalImageUsed)
{
_bookImageView.image = _book.largeBookImage;
}
}
}
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
if(_book.originalImageUsed)
{
_bookImageView.image = _book.largeBookImage;
}
[self.tableView reloadData];
[self.tableView setContentOffset:CGPointZero animated:NO];
}