UIWebview / WKWebView javascript調用處理兩個返回值？

Question

我有一個JavaScript函數，可以返回多個值。 我正在嘗試使用Webview在我的iOS應用中調用該函數。 我曾嘗試搜索類似的問題，但一無所獲。 檢查下面的代碼。 僅供參考，單返回值可以正常工作，我在調用“ webview完成”委托后調用此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))")
})

提前致謝。

Answer 1

您可以在第一次將值設置為true時添加布爾值

//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

我通過返回字典而不是字符串來解決此問題，然后在iOS中使用字典來檢索值。

JavaScript代碼：

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（本機）處理：

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))")
})

希望這可以幫助。