如何使用NSUserDefaults的存储词典的阵列 [英] How to use NSUserDefaults to store an array of dictionaries
本文介绍了如何使用NSUserDefaults的存储词典的阵列的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
尝试存储字典的数组与 NSUserDefaults的
。
VAR theTasks:[[字符串:任何] = [[民:1,称号:榜样,色:红]让默认值= NSUserDefaults.standardUserDefaults()
defaults.setObject(theTasks,forKey:myTasks)
defaults.synchronize()让选择= theTasks [1]
给出错误:
无法将类型'[[字符串:任何]]'价值'?AnyObject到类型期望的参数
块引用>解决方案您只需要把它保存为
AnyObject
数组,并使用NSUserDefaults的
方法arrayForKey
来加载它:让theTasks:[AnyObject] = [[民:1,称号:榜样,色:红]
NSUserDefaults的()的setObject(theTasks,forKey:myTasks)。
如果让loadedTasks NSUserDefaults的=()。arrayForKey(myTasks)作为? [字符串:AnyObject]] {
打印(loadedTasks)
}您还可以创建一个getter和一个setter一个计算的属性来完成所有的幕后工作,你如下:
VAR theTasks:[字符串:AnyObject]] {
获得{
返回NSUserDefaults的()。arrayForKey(myTasks)作为? [字符串:AnyObject]? []
}
集合{
。NSUserDefaults的()的setObject(如为newValue [AnyObject] forKey:myTasks)
}
}打印(theTasks)// [称号:例如,颜色:红,民:1]
theTasks [0] [称号] =又如打印(theTasks)// [称号:另一个例子,颜色:红,民:1]Trying to store an array of dictionaries with
NSUserDefaults
.var theTasks: [[String:Any]] = [["num":1,"title":"example","colour":"red"]] let defaults = NSUserDefaults.standardUserDefaults() defaults.setObject(theTasks, forKey: "myTasks") defaults.synchronize() let selected = theTasks[1]
Gives error:
Cannot convert value of type '[[String:Any]]' to expected argument of type 'AnyObject?'
解决方案You just need to save it as a
AnyObject
array and useNSUserDefaults
methodarrayForKey
to load it:let theTasks: [AnyObject] = [["num":1,"title":"example","colour":"red"]] NSUserDefaults().setObject(theTasks, forKey: "myTasks") if let loadedTasks = NSUserDefaults().arrayForKey("myTasks") as? [[String:AnyObject]] { print(loadedTasks) }
You can also create a computed property with a getter and a setter to do all the work behind the scenes for you as follow:
var theTasks:[[String:AnyObject]] { get { return NSUserDefaults().arrayForKey("myTasks") as? [[String:AnyObject]] ?? [] } set { NSUserDefaults().setObject(newValue as [AnyObject], forKey: "myTasks") } } print(theTasks) // [["title": example, "colour": red, "num": 1]] theTasks[0]["title"] = "another example" print(theTasks) // [["title": another example, "colour": red, "num": 1]]
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