Question

我在这里撕扯我的头发。我的RootViewController从plist加载一个字符串数组。当它加载它工作正常。然后我点击一行将其发送到新的视图控制器。如果我回去，桌子仍然正常，所以我点击另一行按预期工作。现在，如果我回去滚动，我会发现指向cell.textLabel.text = [self.faceCategories objectAtIndex:indexPath.row];

的崩溃

以下摘要源代码：

// RootViewController.h

#import <UIKit/UIKit.h>

@class DetailViewController;

@interface RootViewController : UITableViewController {
    NSMutableArray *faceCategories;
}
@property (nonatomic, retain) NSMutableArray *faceCategories;
@end

RootViewController实现 // RootViewController.m

#import "RootViewController.h"

@synthesize faceCategories;

- (void)viewDidLoad
{
    [super viewDidLoad]; 

    // Init array
    if (self.faceCategories == nil) {
        NSLog(@"NIL NIL NIL NIL NIL NIL NIL NIL NIL");
        NSError *error;
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); //Create a list of paths.
        NSString *documentsDirectory = [paths objectAtIndex:0]; //Get a path to your documents directory from the list.
        NSString *path = [documentsDirectory stringByAppendingPathComponent:@"faceCategories.plist"]; //Create a full file path.

        NSFileManager *fileManager = [NSFileManager defaultManager];

        if (![fileManager fileExistsAtPath: path]) //Check if file exists.

        {
            NSString *bundle = [[NSBundle mainBundle] pathForResource:@"faceCategories" ofType:@"plist"]; //Get a path to your plist created before in bundle directory (by Xcode).
            [fileManager copyItemAtPath:bundle toPath: path error:&error]; //Copy this plist to your documents directory.
        }
        // Zombies percentages after
        NSMutableArray *fileContents = [[NSMutableArray alloc] initWithContentsOfFile: path]; // 55.6%
        self.faceCategories = [[NSMutableArray alloc] initWithArray:fileContents copyItems:YES]; // 33.3%
        [fileContents release]; // 11.1%

    }
}

// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    /////////////////////////////
    // CRASH HERE only after I return to this view controller a couple of times
    // If I enable breakpoints and add a log I can see that faceCategories still contains the right number of objects
    /////////////////////////////
    cell.textLabel.text = [self.faceCategories objectAtIndex:indexPath.row];

    return cell;
}


- (void)dealloc
{
    [faceCategories release];
    [super dealloc];
}

@end

虽然我的记忆管理技巧是基本的，但我看不出有什么特别的错误，所以如果有人这么善良，我会欣赏一双新的眼睛？我觉得特别奇怪的是，当我回到根视图控制器几次时它才会显现出来。

完整来源 - http://pastebin.com/5XzwN0bA

Answer 1

尝试修改：// Zombies percentages after之后的三行：

NSMutableArray *fileContents = [[NSMutableArray alloc] initWithContentsOfFile:path];
self.faceCategories = fileContents;
[fileContents release];

Answer 2

虽然不完全是一个修复，但我发现摆脱这些错误的最简单方法是启用ARC。要执行此操作，请转到编辑＆gt;重构＆gt;转换为Objective-C ARC。

阅读各种ARC博客文章，但这样做意味着我完全忘记了内存管理，并专注于新功能。

苦苦挣扎于EXC_BAD_ACCESS和UITableViewCell

2 个答案: