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如何从executescript转换json数组

.net-core selenium c# javascript

-1

surfmuggle · 技术社区 · 7 年前

范围

我想用selenium进行自动化的web测试并执行javascript。弦 func1 包含我的js函数并将其传递给 ExecuteScript(func1) 它返回一个如下所示的对象数组 {label:'start', time: 121} 是的。

我想把结果 ExecuteScript 进入之内 List<timings>

var result = jsExecutor.ExecuteScript(func1); 
var list = (ReadOnlyCollection<object>)result;
var timings = (List<Timing>)list;

我收到了错误

 Cannot convert type 'System.Collections.ObjectModel.ReadOnlyCollection<object>' 
 to 'System.Collections.Generic.List<CoreConsoleApp.TestExecutions.Timing>'

这是Func1

string func1= @"var t = window.performance.timing;
  var timings = [];
  timings.push({ label: 'navigationStart', time: t.navigationStart  });
  timings.push({ label: 'PageLoadTime', time: t.loadEventEnd - t.navigationStart  });

return timings;" // result is an array of js-objects

下面的代码是selenium部分的一个片段

 public struct Timing
 {
   public string label;
   public int time;            
 }

 using (var driver = new FirefoxDriver())
 {
  ...
  var jsExecutor = (IJavaScriptExecutor)driver;
  var result = jsExecutor.ExecuteScript(func1); 
  var list = (ReadOnlyCollection<object>)result;
 }

问题

硒文档指出 ExecuteScript attempts to return a List 一个数组。 func1应该返回数组 {label: string, time: number} 结果应该很容易预测 var list = (ReadOnlyCollection<object>)result 进入之内 List<string,int> timings = (List<timings>)list;

如何将“system.collections.objectmodel.readonlycollection”强制转换为列表?

更多信息

启动Firefox var driver = new FirefoxDriver() 打开URL driver.Navigate().GoToUrl(url); 找到某个按钮 IWebElement button = driver.FindElement(By.Name("btnK")); 提交表格 button.Submit(); 提交后执行javascript 执行脚本(函数1) 并将结果写入控制台

最重要的是工作。但是我很难将javascript转换成一个c对象列表。

所以我的解决办法是

var result = jsExecutor.ExecuteScript(func1); 
var list = (ReadOnlyCollection<object>)result;

foreach (object item in list)
{   
    var timing = (Dictionary<string, object>)item;
    foreach(KeyValuePair<string, object> kvp in timing)
    {
       Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
    }                    
 }

这表明:

 Key = label, Value = navigationStart
 Key = time, Value = 1529720672670
 Key = label, Value = PageLoadTime
 Key = time, Value = 1194
 Key = label, Value = DOMContentLoadedTime
 Key = time, Value = 589
 Key = label, Value = ResponseTime

3 回复 | 直到 7 年前

bit 7 年前

你需要反序列化 result 进入所需的 List<Timings> 是的。

从中引用json.net包 here
反序列化 结果 (假设是 string )具体如下:

List<Timing> timings = JsonConvert.DeserializeObject<List<Timing>>(result);

以下是有关序列化的一些基本帮助: https://www.newtonsoft.com/json/help/html/SerializingJSON.htm

teamchong 7 年前

在返回之前尝试序列化数据。

string func1= @"var t = window.performance.timing;
var timings = [];
timings.push({ label: 'navigationStart', time: t.navigationStart  });
timings.push({ label: 'PageLoadTime', time: t.loadEventEnd - t.navigationStart  });

return JSON.stringify(timings);" // result is string

并使用 Json.NET

using Newtonsoft.Json.Linq;

string result = Convert.ToString(jsExecutor.ExecuteScript(func1));
Console.Write("result = " + result);
List<Timing> list = JToken.Parse(result).ToObject<List<Timing>>();
Console.Write("result = " + JToken.FromObject(list));

// or access using dynamic
dynamic dynamicList = JToken.Parse(jsExecutor.ExecuteScript(func1)); 
for (var i = 0; i < dynamicList.Count; i++) {
   Console.Write(dynamicList[i]);
}

surfmuggle 7 年前

问题是 var result = jsExecutor.ExecuteScript(func1); 与预期不同。

这个 result 看起来像 List<object>() 我创造了这个 linqpad 程序:

var dictionary1= new Dictionary<string, object>();

dictionary1.Add("label", (object)"PageloadTime");
dictionary1.Add("time", (object)"1087");    
var dictionary2= new Dictionary<string, object>()
{ 
    {"label", (object)"DOMContentLoadedTime"},
    {"time", (object)"494"}
};

var list = new List<object>(); // this is the structure of result
list.Add(dictionary1);
list.Add(dictionary2);  
list.Dump();

如果你打电话 list.Dump(); 看起来是这样的:

如您所见,该结构包含n个此类词典 Dictionary<string, object>(); 因此,我尝试了两个嵌套循环来更好地理解对象的嵌套

Object result = jsExecutor.ExecuteScript(func1); // 

var resultCollection = (ReadOnlyCollection<object>)result;       
foreach (Dictionary<string, object> item in resultCollection)
{
   Console.WriteLine("{0} ", item.GetType()); 
   foreach (KeyValuePair<string, object> kvp in item)
   {
     Console.WriteLine("Keys: {0} Values: {1}", kvp.Key, kvp.Value);
   }
}

最后

// create a structure similar to result
var list = new List<object>(); 
list.Add(dictionary1);
list.Add(dictionary2);  

var timings = new List<Timing>();

foreach (Dictionary<string, object> dict in list)
{       
    Console.WriteLine("Label = {0}  Value ={1} "
              , (string)dict["label"]
              , (string)dict["time"]);
    // create a timing object
    var t = new Timing();
    t.label = (string)dict["label"];
    t.time = (string)dict["time"];
    timings.Add(t);
}

因为有时我得到一个无效的强制转换异常 (int)dict["time"] 我将属性time从int改为string。

更新

正如Steven Chong建议的那样我改变了功能 func1 要返回字符串:

public static string jsGetTiming(){

    // func1 is the javascript function that will get executed
    string func1= @"var t = window.performance.timing; 
    var PageLoadTime =  t.loadEventEnd - t.navigationStart;            
    var ResponseTime = t.responseEnd - t.requestStart;            

    var timings = 'navigationStart=' + t.navigationStart;
        timings += '|PageLoadTime=' + PageLoadTime;        
        timings += '|ResponseTime=' + ResponseTime;            
     return timings;";

   return func1;
}

执行字符串 功能1 作为一个函数,你可以这样调用它

 Object result = jsExecutor.ExecuteScript(MyClass.jsGetTiming());
 // result is a string and looks like this
result = 
 navigationStart=1534377023791|PageLoadTime=943  
   |DOMContentLoadedTime=434|ResponseTime=337
   |Response=269|DomainLookup=0
   |LoadEvent=5|UnloadEvent=8
   |DOMContentLoadedEvent=17