想要从网站上提取数据填充字典，但我在添加它们时失败了。

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英文:

Wants to populate dictionary with data from website, but I fail on adding them

问题

我正在尝试创建一个方法，以从密码保护的网页上获取数据。我使用了Selenium Web Driver来成功连接到网站并登录，但我想将数据存储到我创建的字典中。

  1. // 自定义参数
  2. public class Params_Rezervation
  3. {
  4.     public string Time { get; set; } 
  5.     public string Guests { get; set; } 
  6.     public string Name { get; set; } 
  7.     public string Email { get; set; } 
  8.     public string Status { get; set; } 
  9.     public string Text { get; set; } 
  10.     public string Table { get, set; } 
  11. }
  13. 这是我想在我的字典中拥有的自定义参数，以便我可以访问它们。我尝试创建这个字典。
  15. ```csharp
  16. public static Dictionary<int, Params_Rezervation> rezervace_data = new Dictionary<int, Params_Rezervation>();

然后，我尝试从网站中填充它，但在将数据添加到字典时失败。

  1. public static void LoadReservation()
  2. {
  3.     // 设置Chrome参数
  4.     var chromeOptions = new ChromeOptions();
  5.     chromeOptions.AddArguments("--headless");
  7.     // 隐藏控制台
  8.     var chromeDriverService = ChromeDriverService.CreateDefaultService();
  9.     chromeDriverService.HideCommandPromptWindow = true;
  11.     try
  12.     {
  13.         using (var browser = new ChromeDriver(chromeDriverService, chromeOptions))
  14.         {
  15.             // 设置网站
  16.             browser.Navigate().GoToUrl("specific website");
  18.             // 输入密码 + 提交
  19.             browser.FindElement(By.Id("pwbox-580")).SendKeys("password");
  20.             browser.FindElement(By.Name("Submit")).Click();
  22.             // 查找特定表格
  23.             IWebElement tableElement = browser.FindElement(By.XPath("//*[@id=\"post-580\"]/div/div[2]/table"));
  25.             // 查找行
  26.             IList<IWebElement> rows = tableElement.FindElements(By.XPath(".//tr"));
  28.             // 数据
  29.             int number = 0;
  31.             foreach (IWebElement row in rows)
  32.             {
  33.                 // 查找特定列
  34.                 IList<IWebElement> columns = row.FindElements(By.XPath(".//th"));
  36.                 // 错误行，我不知道如何继续
  37.                 rezervace_data.Add(number, new Params_Rezervation());
  39.                 // 数据填充
  40.                 rezervace_data[number].Time = columns[0].Text;
  41.                 rezervace_data[number].Guests = columns[1].Text;
  42.                 rezervace_data[number].Name = columns[2].Text;
  43.                 rezervace_data[number].Email = columns[3].Text;
  44.                 rezervace_data[number].Text = columns[4].Text;
  45.                 rezervace_data[number].Table = columns[5].Text;
  47.                 number++;
  48.             }
  49.         }
  50.     }
  51.     catch (Exception ex)
  52.     {
  53.         MessageBox.Show("加载数据时发生错误！\n" + ex, "错误", MessageBoxButtons.OK, MessageBoxIcon.Information);
  54.     }
  55. }

我得到的错误：
System.NullReferenceException:“对象引用未设置为对象的实例。”
System.Collections.Generic.Dictionary<TKey, TValue>.this[TKey].get返回null。

我正在尝试学习编程，所以如果有人告诉我需要更改什么，将非常有帮助，因为我是通过自学和网站学习的。

英文:

I am trying to make method where I could scrap data from webpage that's behind password locked form. I used Selenium Web Driver to successfully connect to website and login there, but I would like to store the data do Dicitonary that I made.

// Custom params

  1. public class Params_Rezervation
  2. {
  3.     public string Time { get; set; } 
  4.     public string Guests { get; set; } 
  5.     public string Name { get; set; } 
  6.     public string Email { get; set; } 
  7.     public string Status { get; set; } 
  8.     public string Text { get; set; } 
  9.     public string Table { get; set; } 
  10. }

This is the custom params I would like to have in my dicitonary so I could access them. I tried to make this dictionary.

  1. public static Dictionary&lt;int, Params_Rezervace&gt; rezervace_data = new Dictionary&lt;int, Params_Rezervace&gt;();

Then I tried it populate it with data from website, but I fail on adding data to dictionary.

  1. public static void LoadReservation()
  2.     {
  3.         // Setting up a 
  4.         var chromeOptions = new ChromeOptions();
  5.         chromeOptions.AddArguments(&quot;--headless&quot;);
  7.         // Console hiding
  8.         var chromeDriverService = ChromeDriverService.CreateDefaultService();
  9.         chromeDriverService.HideCommandPromptWindow = true;
  11.         try
  12.         {
  13.             using (var browser = new ChromeDriver(chromeDriverService, chromeOptions))
  14.             {
  15.                 // Setting up a website 
  16.                 browser.Navigate().GoToUrl(&quot;specific website&quot;);
  18.                 // Entering password + submiting it
  19.                 browser.FindElement(By.Id(&quot;pwbox-580&quot;)).SendKeys(&quot;password&quot;);
  20.                 browser.FindElement(By.Name(&quot;Submit&quot;)).Click();
  22.                 // Finding the specific table
  23.                 IWebElement tableElement = browser.FindElement(By.XPath(&quot;//*[@id=\&quot;post-580\&quot;]/div/div[2]/table&quot;));
  25.                 // Finding the row
  26.                 IList&lt;IWebElement&gt; rows = tableElement.FindElements(By.XPath(&quot;.//tr&quot;));
  28.                 // Data
  29.                 int number = 0;
  31.                 foreach (IWebElement row in rows)
  32.                 {
  33.                     // Finding specific columns
  34.                     IList&lt;IWebElement&gt; columns = row.FindElements(By.XPath(&quot;.//th&quot;));
  36.                     //The error line where I dont know how to continue 
  37.                     rezervace_data.Add(number, Params_Rezervace);
  39.                     // Data populating
  40.                     rezervace_data[number].Time = columns[0].Text;
  41.                     rezervace_data[number].Guests = columns[1].Text;
  42.                     rezervace_data[number].Name = columns[2].Text;
  43.                     rezervace_data[number].Email = columns[3].Text;
  44.                     rezervace_data[number].Text = columns[4].Text;
  45.                     rezervace_data[number].Table = columns[5].Text;
  47.                     number++;
  48.                 }
  49.             }
  50.         }
  51.         catch (Exception ex)
  52.         {
  53.             MessageBox.Show(&quot;Error while loading data! \n&quot; + ex, &quot;Error&quot;, MessageBoxButtons.OK, MessageBoxIcon.Information);
  54.         }

Error I get:
System.NullReferenceException: 'The object reference is not set to an instance of the object.'

System.Collections.Generic.Dictionary<TKey, TValue>.this[TKey].get returned null.

I trying to learn programming so If someone will answer me what to change it will be very helpfull, because I am learning it by myself and websites 想要从网站上提取数据填充字典，但我在添加它们时失败了。

答案1

得分: 0

你的“错误行”应该是这样的：

rezervace_data.Add(number, new Params_Rezervace());

你需要在类型为 Params_Rezervace 的字典中添加一个对象，而你可以使用 new 关键词来实现这个操作。

英文:

Your “error line” should be something like this:

rezervace_data.Add(number, new Params_Rezervace());

You need to add an object in your dictionary of type Params_Rezervace, and the way you do that is with the new keyword.

huangapple
  • 本文由 发表于 2023年2月19日 22:55:44
  • 转载请务必保留本文链接：https://go.coder-hub.com/75501002.html
  • c#
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