CoreData使用NSPredicate（swift）有条件地在NSDate上提取 [英] CoreData conditionally fetching on NSDate using NSPredicate (swift)

问题描述

基本上我有一个名为TimeLoc的实体，它有三个属性：时间，纬度和经度。它们的类型分别是Date，Double和Double。

Basically I have an entity called TimeLoc that has three attributes: time, latitude and longitude. And their types are Date, Double and Double respectively. I got stuck when I was trying to make a request with filter on attribute time.

这是我的代码：

...
var appDel: AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate) 
var context: NSManagedObjectContext = self.managedObjectContext!
var request = NSFetchRequest(entityName: "TimeLoc")
var endTime = NSDate()
var startTime = NSDate(timeIntervalSinceNow: -65)
let predicate = NSPredicate(format: "time>= \(startTime) AND time<= \(endTime)")
request.predicate = predicate
var results: NSArray = context.executeFetchRequest(request, error: nil)!
...

我收到以下错误：
'无法解析格式字符串time> = 2015-07-14 03:24:03 +0000 AND time< = 2015-07-14 03:25:08 +0000'

And I got the following error: 'Unable to parse the format string "time>= 2015-07-14 03:24:03 +0000 AND time<= 2015-07-14 03:25:08 +0000"'

我应该如何解决这个问题？我有google，但所有的解决方案，我发现在Objective-C。如果有人可以在Swift回答我，这将是巨大的。

How should I fix this? I have googled a bit but all the solutions I found were in Objective-C. It would be great if someone can answer me in Swift.

编辑：V-Xtreme建议，这个问题的答案可以找到Glauco Neves的答案此问题

As V-Xtreme suggested, an answer to this problem can be find in Glauco Neves's answer to this question

推荐答案

我想你以NSDate格式向谓词发送参数：

I guess you are sending parameters to the predicate in NSDate format :

let predicate = NSPredicate(format: "time>= \(startTime) AND time<= \(endTime)")

b $ b

这里你的startTime和endTime的类型是NSDate。尝试以String格式转换它并将其传递给谓词。它应该工作。

Here your startTime and endTime is of type NSDate . Try to convert it in String format and pass it to the predicate . It should work .

参考： NSPredicate：按NSDate属性的日期过滤对象

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