标签: retaincount

这个问题关系到这一个,但更简单.[我想我可能接近这些愚蠢问题的结尾,可以开始认真的事业:)].

我有一个retain属性,并设置为这样:

UINavigationController *thing = [[UINavigationController alloc] initWithRootViewController:one];
    // thing's retain count is one
navController = thing;
    // thing's retain count is still one!
[thing release];
    // now retain count is zero, which is wrong

我无法理解为什么保留计数变为零.navController被定义为

@property (nonatomic, retain) UINavigationController *navController;

财产不应该将保留计数增加一个吗？

我有一个问题,即发布视图的次数太多了.虽然理论上很简单,因为我将uiview移动到uiview,这是uiview的一个子类,并且是动画的,所以它不是我可以轻松修复的东西.它只会在一定条件下崩溃10%,即使在这些条件下也只有30%的时间.

换句话说,它有点复杂.有时在我的dealloc方法中,此UIView的保留计数已经为1(在视图发布时会释放),因此不应再次释放.所以我做的是这样的:

if ([mainView retainCount] > 1) {
    NSLog(@"released");
    [mainView release];
}

与发布的崩溃一致通常被称为,但并非总是如此,并且当我有时期望它崩溃时它几乎发生.我用这个代码检查了泄漏,它从不泄漏.

现在实际的问题......由于保留计数而释放一些东西是错误的吗？我已经尝试了许多不同的方法来解决这个问题,到目前为止,这是唯一可靠且无泄漏的方法.

编辑:如果没有,那么将一个UIView复制到另一个UIView的更好方法是什么？

mainView = newView;
[newView release];

我尝试先释放mainView,然后在newView上调用copy,但这会崩溃.以上也很有效,除非保留计数有时比预期低1,即使它从未在代码中释放任何其他内容.

我用这个代码.

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.

    view = [[UIView alloc] init];

    [_window addSubview:view];

    [view release];

    NSLog(@"count - %d", [view retainCount]);

    [self.window makeKeyAndVisible];

    return YES;

}


- (IBAction)click{

    NSLog(@"count - %d", [view retainCount]); 

}

当我点击uibutton时 - 我的视图保留计数= 2.为什么会发生这种情况？

我创建了一组相同的自定义类型的对象.所有对象都具有方法showDeleteButton了hideDeleteButton.我发现当我隐藏删除按钮(删除它)按钮时,按下了retainCounter == 2.

这里的代码:

-(void)showDeleteButton {
if(!isDeleteButtonLoaded) { // Check that method was't triggered twice
    UIButton *aDeleteButton = [[UIButton alloc] initWithFrame:CGRectMake(-3, -7, 30, 29)]; // RC == 1
    [aDeleteButton setImage:[UIImage imageNamed:@"close_button.png"] forState:UIControlStateNormal];
    [self addSubview:aDeleteButton]; // RC == 2
    [aDeleteButton addTarget:self action:@selector(deleteButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
    deleteButton = aDeleteButton;
    [aDeleteButton release]; // RC == 1
    isDeleteButtonLoaded = YES;
    NSLog(@"delete button retain count (created): %d", [deleteButton retainCount]);
    [self setNeedsDisplay];
}

}

-(void)deleteButtonPressed:(id)sender {
[delegate deleteImageAtPath:self.imageFullPath];

}

-(void)hideDeleteButton {
if(isDeleteButtonLoaded) {
    NSLog(@"delete …

我已经分析了我的项目:这就是结果:

什么意思,怎么解决这个问题？

我将手动管理NSMutableDictionay的内存,而不使用自动释放.并且mutableDictonary中的每个对象都是NSArray,每次我在mutableDictionary中添加一个数组时,我将使用

NSArray *newArray = [[NSArray arrayWithArray:anArray] retain]
[mutableDict setObject:newArray forKey:@"aKey"];

问题是,我怎么能保证没有内存泄漏？我在dealloc中直接使用[mutableDict release]是好的吗？mutableDict的retainCount是否等于其对象的所有retainCounts(保留的数组)的总和？

据我所知,如果一个对象的保留计数变为0,则会调用dealloc.但是我将保留计数设置为-1.这是什么意思？

我使用以下代码 -

    Demo *obj1 = [[Demo alloc] init];
    NSString *s = [[NSString alloc] initWithString:@"mithilesh"];
    NSString *s1 = [NSString stringWithString:s];
    [s release];
    object_setInstanceVariable(obj1, [propertyName cString], s1);
    //printing retain count 
    NSLog(@"retain count of name = %i",[obj1.name retainCount]);

输出:

   retain count of name = -1

方法stringWithString返回的字符串:何时获取释放？

我写了下面这段代码:

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{

GameViewController *gameViewController = [[GameViewController alloc]initWithLevelNumber:([levelGroup intValue]*100+indexPath.row) Bonus:NO];

NSLog(@"Retain Counter =%d",gameViewController.retainCount);

[navController pushViewController:gameViewController animated:YES];
[gameViewController release];

NSLog(@"Retain Counter=%d",gameViewController.retainCount);

[tableView deselectRowAtIndexPath:indexPath animated:YES];
}

两个日志的结果按顺序1和6!这怎么可能？我只调用一次alloc方法并在将控制器推到堆栈后释放.. alloc-> + 1,push-> + 1,release-> -1 = 1或不？

当我将它从堆栈中弹出时,我希望视图控制器是dealloc'd ..

我们都知道retain方法会为+1 retainCount,释放时会保留-1 retainCount,如果retainCount == 0,则对象dealloc.但是我遇到了一个问题,下面的代码运行得到了荒谬的结果

#import <Foundation/Foundation.h>
@interface Person : NSObject
@property(nonatomic, retain) NSString *name;
@property(nonatomic, assign) NSInteger age;

@end

@implementation Person
- (id)init
{
    self = [super init];
    if (self) {
        self.name = @"name";
        self.age = 20;
    }
    return self;
}

- (void)dealloc
{
    NSLog(@"dealloc");
    [super dealloc];
}
@end

int main(int argc, const char * argv[])
{
    Person *per1 = [[Person alloc] init];
    NSLog(@"retainCount = %lu -- 1",[per1 retainCount]);
    [per1 release];
    [per1 retain];
    NSLog(@"retainCount = %lu -- 2",[per1 retainCount]); …

我在NSNumber整个应用程序(非ARC)中使用不同的语法.为了更加了解情况,我试着看看如何NSNumber保留s,具体取决于它们的初始化语法.所以我做了以下事情:

NSNumber* a = @1;
NSNumber* b = [[NSNumber alloc] initWithInt:2];
NSNumber* c = [NSNumber numberWithInt:3];

NSLog(@"%d | %d | %d", a.retainCount, b.retainCount, c.retainCount);

这个代码片段是用按钮点击执行的,输出让我感到困惑(重复点击):

73 | 27 | 6
78 | 159 | 22
78 | 160 | 22
78 | 161 | 22
78 | 162 | 22
78 | 163 | 22
85 | 169 | 22
85 | 170 | 22
85 | 171 | 22
85 | 172 | 22

现在这并没有真正的目的(至少在我的情况下不是这样),但我想知道这些 …

通过简单的保留/释放方案查看此代码片段:

#import <Foundation/Foundation.h>

@interface SomeClass : NSObject
@end

@implementation SomeClass
@end

int main(int argc, const char * argv[])
{
    SomeClass *aClass = [[SomeClass alloc] init];
    NSLog(@"retainCount: %lu", [aClass retainCount]);

    [aClass retain];
    NSLog(@"retainCount: %lu", [aClass retainCount]);

    [aClass release];
    NSLog(@"retainCount: %lu", [aClass retainCount]);

    [aClass release];
    NSLog(@"retainCount: %lu", [aClass retainCount]);

    return 0;
}

这是结果输出:

2013-04-29 17:33:50.695 retainCount: 1
2013-04-29 17:33:50.697 retainCount: 2
2013-04-29 17:33:50.697 retainCount: 1
2013-04-29 17:33:50.698 retainCount: 1

最后一个retainCount应为"0"或应用程序崩溃.为什么结果为"1"？!

请不要标记重复: - 我创建了几行

NSString *str = [[NSString alloc] init];
str = @"Test";
NSLog(@"%d",[str retainCount]);

和输出是-1.请解释.

请解决这个问题.

NSString *S1 = @"abc";
//retain count of s1 ??

NSString *S2 = [S1 copy];
//retain count of s2 and s1 ??

NSString *S3 = [S2 copy];
//retain count of s3 and s2 ??

NSString *S4 = [S3 retain];
//retain count of s4 and s3 ??

NSString *S1 = @"xyz";
//retain count of s1, s2, s3 and s4 ??

不建议retainCount因为我认为没有给出确切的结果.