React Native Bridging: Passing JSON to Swift funct

2019-07-19 22:52发布

问题:

Im a rookie in Swift and Objective-C but Im trying to make a bridge from React Native to Swift, and send a JSON and a JSON Array as params to Swift.

Inside React I would like to call this function:

startTrack('some url string', { artist: 'Bruce Springsteen', title: 'Born in the USA' }, [{ url: 'url', type: 'image' }, { url: 'another url', type: 'link' ]})

So a string, an object, and a object array.

In my bridge objective-c file i have this:

RCT_EXTERN_METHOD(startTrack:(NSString *)url trackinfo:(NSDictionary *)trackinfo slides:(NSDictionaryArray *)slides)

And in my swift file i have tried a lot of combinations but nothing seems to go through:

  @objc func startTrack(url: String, trackinfo: [String: Any], slides: [[String: Any]]) {
    print("Play test", url, trackinfo, slides)
  }

I get this error message:

How can I send my params all the way through to my Swift file?

Thanks

/Peter

回答1:

Your objective-c method signature set trackingInfo as NSDictionary, but your Swift method signature accepts a Dictionary<String: Any>so this two signature doesn't match.

You have to re-write your method and manually manage NSDictionary to Dictionary cast:

Objective-c

RCT_EXTERN_METHOD(startTrack:(NSString *)url trackinfo:(NSDictionary *)trackinfo slides:(NSDictionaryArray *)slides)

Swift

@objc func startTrack(url: String, trackinfo: NSDictionary, slides: [NSDictionary]) {
    guard let infoDictionary = trackinfo as? [String: Any],
          let slidesDictionary = slides as? [[String: Any]] else {
        return
    } 
    print("Play test", url, infoDictionary, slidesDictionary)
}

JS

startTrack(
  "some url string",
  { artist: "Bruce Springsteen", title: "Born in the USA" },
  [{ url: "url", type: "image" }, { url: "another url", type: "link" }]
);

**notice that you have a typo on JS part