ios 清除 NSUserDefaults

Clearing NSUserDefaults

提问by TonyNeallon

I'm using +[NSUserDefaults standardUserDefaults]to store application settings. This consists of roughly a dozen string values. Is it possible to delete these values permanently instead of just setting them to a default value?

我+[NSUserDefaults standardUserDefaults]用来存储应用程序设置。这包括大约十几个字符串值。是否可以永久删除这些值而不是将它们设置为默认值？

回答by Christopher Rogers

You can remove the application's persistent domain like this:

您可以像这样删除应用程序的持久域：

NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];

In Swift 3 and later:

在 Swift 3 及更高版本中：

if let bundleID = Bundle.main.bundleIdentifier {
    UserDefaults.standard.removePersistentDomain(forName: bundleID)
}

This is similar to the answer by @samvermette but is a little bit cleaner IMO.

这与@samvermette 的答案相似，但 IMO 更简洁一些。

回答by samvermette

This code resets the defaults to the registration domain:

此代码将默认值重置为注册域：

[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];

In other words, it removeObjectForKeyfor every single key you ever registered in that app.

换句话说，它removeObjectForKey适用于您在该应用程序中注册的每个密钥。

Credits to Ken Thomases on this Apple Developer Forums thread.

在此 Apple Developer Forums帖子中感谢 Ken Thomases 。

回答by sbooth

Did you try using -removeObjectForKey?

您是否尝试使用 - removeObjectForKey？

 [[NSUserDefaults standardUserDefaults] removeObjectForKey:@"defunctPreference"];

回答by juliensaad

Here is the answer in Swift:

这是斯威夫特的答案：

let appDomain = NSBundle.mainBundle().bundleIdentifier!
NSUserDefaults.standardUserDefaults().removePersistentDomainForName(appDomain)

回答by Roger Sanoli

If you need it while developing, you can also reset your simulator, deleting all the NSUserDefaults.

如果您在开发时需要它，您还可以重置您的模拟器，删除所有NSUserDefaults.

iOS Simulator -> Reset Content and Settings...

iOS 模拟器 -> 重置内容和设置...

Bear in mind that it will also delete all the apps and files on simulator.

请记住，它还会删除模拟器上的所有应用程序和文件。

回答by folse

NSDictionary *defaultsDictionary = [[NSUserDefaults standardUserDefaults] dictionaryRepresentation];
for (NSString *key in [defaultsDictionary allKeys]) {
                    [[NSUserDefaults standardUserDefaults] removeObjectForKey:key];
}

回答by Adam Waite

In Swift:

在斯威夫特：

let defaults = NSUserDefaults.standardUserDefaults()
defaults.dictionaryRepresentation().keys.forEach { defaults.removeObjectForKey(
extension NSUserDefaults {
    func clear() {
        guard let domainName = NSBundle.mainBundle().bundleIdentifier else {
            return
        }

        self.removePersistentDomainForName(domainName)
    }
}
) }

回答by Valentin Shergin

I love extensions when they make the code cleaner:

我喜欢使代码更简洁的扩展：

extension UserDefaults {
    func clear() {
        guard let domainName = Bundle.main.bundleIdentifier else {
            return
        }
        removePersistentDomain(forName: domainName)
        synchronize()
    }
}

Swift 5

斯威夫特 5

[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:[[NSBundle mainBundle] bundleIdentifier]];

回答by Hemang

Note: This answer has been updated for Swift too.

注意：此答案也已针对 Swift 进行了更新。

What about to have it on one line?

把它放在一条线上怎么样？

Extending @Christopher Rogers answer – the accepted one.

扩展@Christopher Rogers 的回答——已被接受的回答。

[[NSUserDefaults standardUserDefaults] synchronize];

and yes, sometime you may need to synchronizeit,

是的，有时你可能需要synchronize它，

- (void) clearDefaults {
    [[NSUserDefaults standardUserDefaults] removePersistentDomainForName:[[NSBundle mainBundle] bundleIdentifier]];
    [[NSUserDefaults standardUserDefaults] synchronize];
}

I've created a method to do this,

我已经创建了一个方法来做到这一点，

extension UserDefaults {
    class func clean() {
        guard let aValidIdentifier = Bundle.main.bundleIdentifier else { return }
        standard.removePersistentDomain(forName: aValidIdentifier)
        standard.synchronize()
    }
}

---

---

Swift?

斯威夫特？

With swift its even more easy.

有了 swift 就更容易了。

UserDefaults.clean()

And usage:

和用法：

osascript -e 'tell application "iOS Simulator" to quit'
xcrun simctl list devices | grep -v '^[-=]' | cut -d "(" -f2 | cut -d ")" -f1 | xargs -I {} xcrun simctl erase "{}"

回答by Daniel Gomez Rico

I found this:

我找到了这个：

##代码##

Source: https://gist.github.com/ZevEisenberg/5a172662cb576872d1ab

来源：https: //gist.github.com/ZevEisenberg/5a172662cb576872d1ab