好了，两天以来我一直试图解决我在cellForRowAtIndex方法中的错误，让我先说我已经跟踪了这个方法的错误，错误是[CFDictionary image]或[Not a “类型图像”消息发送到解除分配的实例。
我知道调试标志，NSZombie，MallocStack和其他人，他们帮助我将其缩小到这个方法以及原因，但除了重新设计应用程序UI之外我不知道如何解决。
那么我想要做什么，以及这段代码，显示购买细节，其中包含项目，项目在自己的部分，现在当处于编辑模式时，在底部出现一个单元格标签为“添加新项目”的项目部分，此按钮将显示添加项目控制器的模态视图，项目已添加，视图返回到购买详细信息屏幕，刚刚添加的项目位于上方的部分中“添加新项目”单元格，问题发生在我滚动项目部分关闭屏幕并返回查看应用程序崩溃与EXC_BAD_ACCESS，或即使我不滚动，而是点击导航栏上的后退按钮，仍然是相同的错误
- (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
现在我知道导致错误的是什么，我如何解决它，我已经尝试了我所知道的一切以及我不知道的一些但仍然没有进展，请不要重新设计如何解决这个问题的任何建议是我的目标，也许我正在做一个我无法看到的错误，但如果这是自动释放的本质，那么我将重新设计。
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
答案 0 :(得分：0)
与添加项控制器有关的事情可能会过度释放您添加的singleItem中的图像。然后，当单元格在屏幕外滚动并重新使用时，它会被释放，然后在重新显示时崩溃。如果这是真的，问题将出在-cellForRowAtIndexPath：。
之外如果你没有看到任何明显的东西，你可以使用gdb命令bt 3（左右）在[PurchaseItem retain]和[PurchaseItem release]上放置连续断点，然后查看释放它的内容。您可能需要查看图像本身的保留和释放。
您是否尝试运行静态代码分析器以查看是否存在相关的内存管理错误？
另一件事：将消息-image发送到图像似乎很奇怪。 singleItem.image的类究竟是什么？
答案 1 :(得分：0)
在AddItemViewController中查看你的save：方法，我看不到保留项目的位置。它是自动释放的，所以它需要保留在某个地方。有可能：
[purchase addItemsObject:item]
保留它，但我必须看到该代码。
编辑：
将此添加到save：方法：
[item retain];
我没看到如何保留项目。由于它的自动释放项目将是一个糟糕的指针，导致您的错误。并且因为当你卸载/加载视图和viewDidLoad：references项时你说错误显示为iself，我认为这是一个很好的可能性。我不完全确定，因为我不知道购买的等级等级。