好的，这两天我一直在尝试解决我在 cellForRowAtIndex 方法中遇到的错误，首先说我已经找到了这个方法的错误，错误是 [CFDictionary image] 或 [Not a Type image]消息发送到解除分配的实例。
我知道调试标志、NSZombie、MallocStack 等，它们帮助我将范围缩小到这种方法以及为什么，但除了重新设计应用程序 UI 之外，我不知道如何解决。
所以我想做什么，对于这个代码块，显示一个购买详细信息，其中包含项目，项目在自己的部分中，现在在编辑模式下，项目部分底部出现一个单元格“添加新商品”的标签，此按钮将呈现添加商品控制器的模式视图，添加商品并返回购买详细信息屏幕，刚刚添加的商品在“添加新商品”上方的部分项目”单元格，当我将项目部分滚动到屏幕外并返回查看应用程序崩溃时出现问题，或者即使我不滚动而是点击导航栏上的后退按钮，仍然是同样的错误。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = nil;
switch (indexPath.section)
{
case PURCHASE_SECTION:
{
static NSString *cellID = @"GenericCell";
cell = [tableView dequeueReusableCellWithIdentifier:cellID];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue2
reuseIdentifier:cellID] autorelease];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
switch (indexPath.row)
{
case CATEGORY_ROW:
cell.textLabel.text = @"Category:";
cell.detailTextLabel.text = [self.purchase.category valueForKey:@"name"];
cell.accessoryType = UITableViewCellAccessoryNone;
cell.editingAccessoryType = UITableViewCellAccessoryDisclosureIndicator;
break;
case TYPE_ROW:
cell.textLabel.text = @"Type:";
cell.detailTextLabel.text = [self.purchase.type valueForKey:@"name"];
cell.accessoryType = UITableViewCellAccessoryNone;
cell.editingAccessoryType = UITableViewCellAccessoryDisclosureIndicator;
break;
case VENDOR_ROW:
cell.textLabel.text = @"Payment:";
cell.detailTextLabel.text = [self.purchase.vendor valueForKey:@"name"];
cell.accessoryType = UITableViewCellAccessoryNone;
cell.editingAccessoryType = UITableViewCellAccessoryDisclosureIndicator;
break;
case NOTES_ROW:
cell.textLabel.text = @"Notes";
cell.editingAccessoryType = UITableViewCellAccessoryNone;
break;
default:
break;
}
break;
}
case ITEMS_SECTION:
{
NSUInteger itemsCount = [items count];
if (indexPath.row < itemsCount)
{
static NSString *itemsCellID = @"ItemsCell";
cell = [tableView dequeueReusableCellWithIdentifier:itemsCellID];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:itemsCellID] autorelease];
cell.accessoryType = UITableViewCellAccessoryNone;
}
singleItem = [self.items objectAtIndex:indexPath.row];
cell.textLabel.text = singleItem.name;
cell.detailTextLabel.text = [singleItem.amount formattedDataDisplay];
cell.imageView.image = [singleItem.image image];
}
else
{
static NSString *AddItemCellID = @"AddItemCell";
cell = [tableView dequeueReusableCellWithIdentifier:AddItemCellID];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:AddItemCellID] autorelease];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
cell.textLabel.text = @"Add Item";
}
break;
}
case LOCATION_SECTION:
{
static NSString *localID = @"LocationCell";
cell = [tableView dequeueReusableCellWithIdentifier:localID];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:localID] autorelease];
cell.accessoryType = UITableViewCellAccessoryNone;
}
cell.textLabel.text = @"Purchase Location";
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
cell.editingAccessoryType = UITableViewCellAccessoryNone;
break;
}
default:
break;
}
return cell;
}
singleItem 是核心数据的模态类型 PurchaseItem
既然我知道是什么导致了错误，我该如何解决它，我已经尝试了我所知道的所有内容以及我不知道的一些内容，但仍然没有进展，请任何关于如何在不重新设计的情况下解决这个问题的建议是我的目标，也许我正在做一个我看不到的错误，但如果这是自动释放的性质，我会重新设计。
更新：添加 AddItemController
//
// AddItemViewController.m
// spendTrac
//
// Created by iAm on 3/5/10.
// Copyright 2010 heariamStudios. All rights reserved.
//
#import "AddItemViewController.h"
#import "Purchase.h"
#import "PurchaseItem.h"
#import "FormattedDataDisplay.h"
#import "ModalAlert.h"
#import "UtilityBelt.h"
@implementation AddItemViewController
@synthesize purchase, item, itemAmount, itemImage;
@synthesize amountPadBtn, nameAlertBtn, addImageBtn;
@synthesize amountLab, itemNameLab;
@synthesize itemImageView;
#pragma mark -
#pragma mark IBAction Methods
- (void)cancel:(id)sender
{
[self.navigationController popViewControllerAnimated:YES];
}
- (void)save:(id)sender
{
NSManagedObjectContext *context = purchase.managedObjectContext;
if (!item)
{
itemImage = [NSEntityDescription insertNewObjectForEntityForName:@"Image" inManagedObjectContext:context];
item = [NSEntityDescription insertNewObjectForEntityForName:@"PurchaseItem" inManagedObjectContext:context];
[purchase addItemsObject:item];
item.displayOrder = [NSNumber numberWithInteger:[purchase.items count]];
}
NSString *stringAmt = [UtilityBelt charStripper:self.amountLab.text];
NSDecimalNumber *amount = [NSDecimalNumber decimalNumberWithString:stringAmt];
[itemImage setValue:self.itemImageView.image forKey:@"image"];
item.image = itemImage;
item.name = itemNameLab.text;
item.amount = amount;
NSError *error = nil;
if (![context save:&error])
{
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
[self.navigationController popViewControllerAnimated:YES];
}
- (void)amountPadButtonTapped:(id)sender
{
AmountPad *amountPad = [[AmountPad alloc]initWithNibName:@"AmountPad" bundle:nil];
amountPad.delegate = self;
[self.navigationController presentModalViewController:amountPad animated:YES];
[amountPad release];
}
- (void)nameAlertButtonTapped:(id)sender
{
NSString *answer = [ModalAlert ask:@"Name This Item" withTextPrompt:@"item name"];
if (answer)
{
self.itemNameLab.text = [NSString stringWithFormat:@"%@", answer];
}
else
{
[ModalAlert say:@"What, You Don't Know!"];
}
}
- (void)photoButtonTapped:(id)sender
{
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
imagePicker.delegate = self;
imagePicker.allowsEditing = YES;
imagePicker.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:imagePicker.sourceType];
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
}
else {
imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
}
[self presentModalViewController:imagePicker animated:YES];
[imagePicker release];
}
- (void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingImage:(UIImage *)selectedImage
editingInfo:(NSDictionary *)editingInfo
{
// Create a thumbnail version of the image for the item object.
CGSize size = selectedImage.size;
CGFloat ratio = 0;
if (size.width > size.height) {
ratio = 277.3 / size.width;
} else {
ratio = 277.3 / size.height;
}
CGRect rect = CGRectMake(0.0, 0.0, ratio * size.width, ratio * size.height);
UIGraphicsBeginImageContext(rect.size);
[selectedImage drawInRect:rect];
self.itemImageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[self dismissModalViewControllerAnimated:YES];
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
[self dismissModalViewControllerAnimated:YES];
}
#pragma mark -
#pragma mark View Controller Methods
- (void)viewDidLoad
{
if (self.item)
{
self.itemImage = self.item.image;
self.itemImageView.image = [self.item.image image];
self.itemNameLab.text = self.item.name;
self.amountLab.text = [self.item.amount formattedDataDisplay];
}
UINavigationItem *navigationItem = self.navigationItem;
navigationItem.title = @"Item";
UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel
target:self
action:@selector(cancel:)];
self.navigationItem.leftBarButtonItem = cancelButton;
[cancelButton release];
UIBarButtonItem *saveButton = [[UIBarButtonItem alloc] initWithTitle:@"Save"
style:UIBarButtonSystemItemSave
target:self
action:@selector(save:)];
self.navigationItem.rightBarButtonItem = saveButton;
[saveButton release];
[super viewDidLoad];
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload
{
// Release any retained subviews of the main view.
self.amountLab = nil;
self.itemNameLab = nil;
self.addImageBtn = nil;
self.nameAlertBtn = nil;
self.amountPadBtn = nil;
[super viewDidUnload];
}
#pragma mark -
#pragma mark AmountPadDelegate Method
- (void)amountPadDidPressDoneButton:(NSString *)amount
{
NSDecimalNumber *itemAmt = [NSDecimalNumber decimalNumberWithString:amount];
self.amountLab.text = [itemAmt formattedDataDisplay];
[self dismissModalViewControllerAnimated:YES];
}
#pragma mark -
#pragma mark Memory Management
- (void)dealloc
{
[addImageBtn release];
[nameAlertBtn release];
[amountPadBtn release];
[itemAmount release];
[purchase release];
[item release];
[itemImage release];
[itemImageView release];
[amountLab release];
[itemNameLab release];
[super dealloc];
}
@end