iOS Swift:调用单例方法 3 次会导致应用程序崩溃 [英] iOS Swift: Calling a singleton method 3 times causes app to crash

问题描述

我有客观/快速的代码并排.我调用了 3 次 swift 单例方法.三遍之后就崩溃了.我有理由相信这可能是内存问题.这是我的代码

I have objective / swift code side by side. I am calling a swift singleton method 3 times. After three times it crashes. I have reason to believe this might be a memory problem. Here is my code

ViewController.m

ViewController.m

-(void)sharedData
{
    // called three times
    sharedData = [SharedData sharedData];
    [sharedData initSyncManager];
}

Swift 共享数据类

Swift sharedData class

class func sharedData() -> SharedData 
{
    struct Singleton 
    {
        static let instance = SharedData()
    }
    return Singleton.instance
}

func initSyncManager()
{

}

这一行的错误是 EXC_BAD_ACCESS (code=EXC_i386_GPFLT)

The error is EXC_BAD_ACCESS (code=EXC_i386_GPFLT) on this line

'return Singleton.instance'

我不知道为什么会发生这种情况.我在 initSyncManager 中根本没有代码，只有当我使用这段代码时才会发生这种崩溃

I have no idea why this is occurring. I have no code in initSyncManager at all and this crash only happens when I use this piece of code

[sharedData initSyncManager];

如果我不调用该方法 3 次，则不会发生崩溃.

If I don't call the method 3 times, the crash doesn't occur.

推荐答案

你可以试试这个，因为我正在使用它(在 Swift 2.1 中)来创建单例类，它对我来说很好:

You may try this, as I am using this (in Swift 2.1) for creating singleton classes and it's working fine for me:

class var sharedInstance: SharedData {
    struct Static {
        static var onceToken: dispatch_once_t = 0
        static var instance: SharedData? = nil
    }
    dispatch_once(&Static.onceToken) {
        Static.instance = SharedData()
    }
    return Static.instance!
}

override init() {
    super.init()
    //initialisation
}

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