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在方法作用域中释放“引用”变量

xcode cocoa-touch iphone objective-c

typeoneerror · 技术社区 · 15 年前

在objective-c(cocoa touch)中,我有一系列的uiviewcontrollers可以在它们之间切换。

- (void)switchViews:(id)sender
{
    UIButton *button = (UIButton *)sender;
    UIViewController *nextViewController;
    int tag = button.tag;

    switch (tag)
    {
        // -- has already been created
        case kFinancialButton:
            nextViewController = financials;
            break;

        case kSocialButton:
            if (social == nil)
            {
                SocialViewController *socialViewController = [[SocialViewController alloc] initWithNibName:@"SocialViewController" bundle:nil];
                social = socialViewController;
                [socialViewController release];
            }
            nextViewController = social;
            break;

        case kTicketingButton:
            if (ticketing == nil)
            { 
                TicketingViewController *ticketingViewController = [[TicketingViewController alloc] initWithNibName:@"TicketingViewController" bundle:nil];
                ticketing = ticketingViewController;
                [ticketingViewController release];
            }
            nextViewController = ticketing;
            break;
    }

        ///////
------> // -- [button/nextViewController release]????
        ///////

    [self setActiveButton:button];
}

如您所见,我正在将一个视图控制器分配给“nextviewcontroller”。我想知道的是,我是否需要释放这个“local”变量,或者是否可以不使用它,因为它只指向我的一个视图控制器(我在dealloc中释放)。我不认为“标签”需要释放,因为它是一个“原始的”,对吧?巴顿怎么样?我不太明白应该和不应该明确发布什么,所以我可能是过于谨慎了。提前谢谢。

1 回复 | 直到 15 年前

Bryan McLemore 15 年前

一般来说你只需要 release 一个变量 retain D init D或 copy D

编辑:

在多读了一点代码之后,您可能会遇到其他错误值的问题。下面的代码对我来说更有意义。这假设财务、社会和票务 @synthesized 伊瓦尔斯

- (void)switchViews:(id)sender
{
    UIButton *button = (UIButton *)sender;
    UIViewController *nextViewController;
    int tag = button.tag;

    switch (tag)
    {
        // -- has already been created
        case kFinancialButton:
            nextViewController = self.financials;
            break;

        case kSocialButton:
            if (!social) {
                self.social = [[[SocialViewController alloc] initWithNibName:@"SocialViewController" bundle:nil] autorelease];
            }
            nextViewController = self.social;
            break;

        case kTicketingButton:
            if (!ticketing) {
                self.ticketing = [[[TicketingViewController alloc] initWithNibName:@"TicketingViewController" bundle:nil] autorelease];
            }
            nextViewController = self.ticketing;
            break;
    }

    // Do something with nextViewController I'd assume

    [self setActiveButton:button];
}