有一个 BNRItemStore 的单例类，但是当我尝试调用它时，我得到了导致 ARC 问题的上述错误。已将错误注释掉。
细节视图控制器.m
#import "DetailViewController.h"
#import "BNRItem.h"
#import "BNRImageStore.h"
#import "BNRItemStore.h"
@implementation DetailViewController
@synthesize item;
-(id)initForNewItem:(BOOL)isNew
{
self = [super initWithNibName:@"DetailViewController" bundle:nil];
if(self){
if (isNew) {
UIBarButtonItem *doneItem = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemDone
target:self
action:@selector(save:)];
[[self navigationItem] setRightBarButtonItem:doneItem];
UIBarButtonItem *cancelItem = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemCancel
target:self
action:@selector(cancel:)];
[[self navigationItem] setLeftBarButtonItem:cancelItem];
}
}
return self;
}
-(id)initWithNibName:(NSString *)nibName bundle:(NSBundle *)bundle
{
@throw [NSException exceptionWithName:@"Wrong initializer"
reason:@"Use initForNewItem:"
userInfo:nil];
return nil;
}
-(void)viewDidLoad
{
[super viewDidLoad];
UIColor *clr = nil;
if ([[UIDevice currentDevice]userInterfaceIdiom]== UIUserInterfaceIdiomPad) {
clr = [UIColor colorWithRed:0.875 green:0.88 blue:0.91 alpha:1];
} else {
clr = [UIColor groupTableViewBackgroundColor];
}
[[self view]setBackgroundColor:clr];
}
- (void)viewDidUnload {
nameField = nil;
serialNumberField = nil;
valueField = nil;
dateLabel = nil;
imageView = nil;
[super viewDidUnload];
}
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[nameField setText:[item itemName]];
[serialNumberField setText:[item serialNumber]];
[valueField setText:[NSString stringWithFormat:@"%d", [item valueInDollars]]];
// Create a NSDateFormatter that will turn a date into a simple date string
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterNoStyle];
// Use filtered NSDate object to set dateLabel contents
[dateLabel setText:[dateFormatter stringFromDate:[item dateCreated]]];
NSString *imageKey = [item imageKey];
if (imageKey) {
// Get image for image key from image store
UIImage *imageToDisplay = [[BNRImageStore sharedStore]imageForKey:imageKey];
// Use that image to put on the screen in imageview
[imageView setImage:imageToDisplay];
} else {
// Clear the imageview
[imageView setImage:nil];
}
}
-(void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
// Clear first responder
[[self view]endEditing:YES];
// "Save" changes to item
[item setItemName:[nameField text]];
[item setSerialNumber:[serialNumberField text]];
[item setValueInDollars:[[valueField text] intValue]];
}
-(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)io
{
if ([[UIDevice currentDevice]userInterfaceIdiom]==UIUserInterfaceIdiomPad) {
return YES;
} else {
return (io==UIInterfaceOrientationPortrait);
}
}
-(void)setItem:(BNRItem *)i
{
item = i;
[[self navigationItem] setTitle:[item itemName]];
}
- (IBAction)takePicture:(id)sender {
if ([imagePickerPopover isPopoverVisible]) {
// If the popover is already up, get rid of it
[imagePickerPopover dismissPopoverAnimated:YES];
imagePickerPopover = nil;
return;
}
UIImagePickerController *imagePicker =
[[UIImagePickerController alloc]init];
// If our device has a camera, we want to take a picture, otherwise, we
// just pick from the photo library
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
[imagePicker setSourceType:UIImagePickerControllerSourceTypeCamera];
} else {
[imagePicker setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
// This line of code will generate a warning right now, ignore it
[imagePicker setDelegate:self];
//Place image picker on the screen
// Check for iPad device before instantiating the popover controller
if ([[UIDevice currentDevice]userInterfaceIdiom]==UIUserInterfaceIdiomPad) {
// Create a new popover controller that will display the imagepicker
imagePickerPopover = [[UIPopoverController alloc]initWithContentViewController:imagePicker];
[imagePickerPopover setDelegate:self];
// Display the popover controller; sender
// is the camera bar button item
[imagePickerPopover presentPopoverFromBarButtonItem:sender permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
} else {
[self presentViewController:imagePicker animated:YES completion:nil];
}
}
}
-(void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController
{
NSLog(@"User dismissed popover");
imagePickerPopover = nil;
}
- (IBAction)backgroundTapped:(id)sender {
[[self view]endEditing:YES];
}
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSString *oldKey = [item imageKey];
// Did the item already have an image?
if (oldKey) {
// Delete the old image
[[BNRImageStore sharedStore]deleteImageForKey:oldKey];
}
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
// Create a CFUUID object - it knows how to create unique identifier strings
CFUUIDRef newUniqueID = CFUUIDCreate(kCFAllocatorDefault);
// Create a string from unique identifier
CFStringRef newUniqueIDString = CFUUIDCreateString(kCFAllocatorDefault, newUniqueID); // Incompatible integer to pointer conversion initializing
// Use that unique ID to set our item's imageKey
NSString *key = (__bridge NSString *)newUniqueIDString;
[item setImageKey:key];
// Store image in the BNRImageStore with this key
[[BNRImageStore sharedStore] setImage:image forKey:[item imageKey]];
CFRelease(newUniqueIDString);
CFRelease(newUniqueID);
[imageView setImage:image];
if ([[UIDevice currentDevice]userInterfaceIdiom]==UIUserInterfaceIdiomPad) {
// If on the phone, the image picker is presented modally. Dismiss it.
[self dismissViewControllerAnimated:YES completion:nil];
} else {
// If on the pad, the image picker is in the popover. Dismiss the popover.
[imagePickerPopover dismissPopoverAnimated:YES];
imagePickerPopover = nil;
}
}
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
[textField resignFirstResponder];
return YES;
}
-(void)save:(id)sender
{
[[self presentingViewController]dismissViewControllerAnimated:YES
completion:nil];
}
-(void)cancel:(id)sender
{
// If the user cancelled, then remove the BNRItem from the store
[[BNRItemStore sharedStore]removeItem:item]; // No known class method for selector 'sharedStore'
[[self presentingViewController]dismissViewControllerAnimated:YES completion:nil];
}
DetailViewController.h
#import <UIKit/UIKit.h>
@class BNRItem;
@interface DetailViewController : UIViewController <UINavigationControllerDelegate, UIImagePickerControllerDelegate,UITextFieldDelegate, UIPopoverControllerDelegate>
{
__weak IBOutlet UITextField *nameField;
__weak IBOutlet UITextField *serialNumberField;
__weak IBOutlet UITextField *valueField;
__weak IBOutlet UILabel *dateLabel;
__weak IBOutlet UIImageView *imageView;
UIPopoverController *imagePickerPopover;
}
@property(nonatomic,strong)BNRItem *item;
-(id)initForNewItem:(BOOL)isNew;
- (IBAction)takePicture:(id)sender;
- (IBAction)backgroundTapped:(id)sender;
@end
BNRItemStore.m
#import "BNRItemStore.h"
#import "BNRItem.h"
@implementation BNRItemStore
+ (BNRItemStore *)defaultStore
{
static BNRItemStore *defaultStore = nil;
if(!defaultStore)
defaultStore = [[super allocWithZone:nil] init];
return defaultStore;
}
+ (id)allocWithZone:(NSZone *)zone
{
return [self defaultStore];
}
- (id)init
{
self = [super init];
if(self) {
allItems = [[NSMutableArray alloc] init];
}
return self;
}
- (void)removeItem:(BNRItem *)p
{
[allItems removeObjectIdenticalTo:p];
}
- (NSArray *)allItems
{
return allItems;
}
- (void)moveItemAtIndex:(int)from
toIndex:(int)to
{
if (from == to) {
return;
}
// Get pointer to object being moved so we can re-insert it
BNRItem *p = [allItems objectAtIndex:from];
// Remove p from array
[allItems removeObjectAtIndex:from];
// Insert p in array at new location
[allItems insertObject:p atIndex:to];
}
- (BNRItem *)createItem
{
BNRItem *p = [BNRItem randomItem];
[allItems addObject:p];
return p;
}
@end
BNRItemStore.h
#import <Foundation/Foundation.h>
@class BNRItem;
@interface BNRItemStore : NSObject
{
NSMutableArray *allItems;
}
+ (BNRItemStore *)defaultStore;
- (void)removeItem:(BNRItem *)p;
- (NSArray *)allItems;
- (BNRItem *)createItem;
- (void)moveItemAtIndex:(int)from
toIndex:(int)to;
@end