Swift - Cast Int into enum:Int
IosXcodeSwiftIos Problem Overview
I am very new to Swift (got started this week) and I'm migrating my app from Objective-C. I have basically the following code in Objective-C that works fine:
typedef enum : int {
MyTimeFilter1Hour = 1,
MyTimeFilter1Day = 2,
MyTimeFilter7Day = 3,
MyTimeFilter1Month = 4,
} MyTimeFilter;
...
- (void)selectFilter:(id)sender
{
self.timeFilterSelected = (MyTimeFilter)((UIButton *)sender).tag;
[self closeAnimated:YES];
}
When translating it to Swift, I did the following:
enum MyTimeFilter : Int {
case OneHour = 1
case OneDay = 2
case SevenDays = 3
case OneMonth = 4
}
...
@IBAction func selectFilter(sender: AnyObject) {
self.timeFilterSelected = (sender as UIButton).tag as MyTimeFilter
self.close(true)
}
By doing that, I get the error :
> 'Int' is not convertible to 'MyTimeFilter'
I don't know if my approach (using the tag property) is the best, but anyway I need to do this kind of casting in different places in my app. Does anyone have an idea of how to get rid of this error?
Thanks!
Ios Solutions
Solution 1 - Ios
Use the rawValue
initializer: it's an initializer automatically generated for enum
s.
self.timeFilterSelected = MyTimeFilter(rawValue: (sender as UIButton).tag)!
see: The Swift Programming Language § Enumerations
NOTE: This answer has changed. Earlier version of Swift use the class method fromRaw()
to convert raw values to enumerated values.
Solution 2 - Ios
Swift 5
@IBAction func selectFilter(sender: AnyObject) {
timeFilterSelected = MyTimeFilter(rawValue: sender.tag)
}
Solution 3 - Ios
elaborating on Jeffery Thomas's answer. to be safe place a guard statement unwrap the cast before using it, this will avoid crashes
@IBAction func selectFilter(sender: AnyObject) {
guard let filter = MyTimeFilter(rawValue: (sender as UIButton).tag) else {
return
}
timeFilterSelected = filter
}