UIWebview/WKWebView javascript调用处理两个返回值？

Question

我有一个返回多个值的 javascript 函数。我正在尝试使用 Webview 在我的 iOS 应用程序中调用该函数。我曾尝试搜索类似的问题，但一无所获。检查下面的代码。仅供参考，单个返回值工作正常，我在调用“webview 完成”委托后调用此 javascript。

//Javascript function
function listABCs() constant returns (uint noOfABCs, address[] retABCAddresses) {
    return (abcAddresses.length, abcAddresses);
}

//iOS code
let script = "getAbcList()"
wkWebView?.evaluateJavaScript(script, completionHandler: { (response: Any?, error:Error?) in
       print("\n Error \(String(describing: error))")
       let res = response as? String
       print("Response = \(String(describing: response))")
})

提前致谢。

Answer 1

您可以在第一次收到您的值后添加一个布尔值，将其设置为 true

//Create a variable received response
var receivedResponse = false

let script = "getKycList()"
wkWebView?.evaluateJavaScript(script, completionHandler: { (response: Any?, error:Error?) in
   print("\n Error \(String(describing: error))")
   if !receivedResponse {
      if let res = response as? String {
          // use the response now
          print("Response = \(res)")

         // set the receivedResponse to true
         receivedResponse = true
      }

   }

})

Answer 2

我通过返回字典而不是字符串来解决这个问题，然后在 iOS 中使用字典来检索值。

Javascript 代码：

function customDictFrom(val1, val2) {

    var data_to_pass = {
        'val1': val1,
        'val2': val2
    };

    return data_to_pass;
}

function listABCs() constant returns (uint noOfABCs, address[] retABCAddresses) {
    var data_to_pass = customDictFrom(abcAddresses.length, abcAddresses);
    return data_to_pass;
}

Swift（原生）处理：

let script = "getAbcList()"
wkWebView?.evaluateJavaScript(script, completionHandler: { (response: Any?, error:Error?) in
       print("\n Error \(String(describing: error))")
       let res = response as? [String: Any] //Your response is here as a dictionary
       print("Response = \(String(describing: response))")
})

希望这会有所帮助。