Nod*_*ame 5 html javascript c# web
我正在尝试从中提取数据的网页.通过查看页面Source中的HTML,我可以在脚本标记中找到我感兴趣的数据.它看起来如下:
<html>
<script type="text/javascript">
window.gon = {};
gon.default_profile_mode = false;
gon.user = null;
gon.product = "shoes";
gon.books_jsonarray = [
{
"title": "Little Sun",
"authors": [
"John Smith"
],
edition: 2,
year: 2009
},
{
"title": "Little Prairie",
"authors": [
"John Smith"
],
edition: 3,
year: 2009
},
{
"title": "Little World",
"authors": [
"John Smith",
"Mary Neil",
"Carla Brummer"
],
edition: 3,
year: 2014
}
];
</script>
</html>
我想要实现的是,使用其URL调用网页,然后从JavaScript中检索'gon'变量并将其存储在C#变量中.换句话说,在C#中,我希望有一个数据结构(例如字典),它将保存'gon'的值.
我已经尝试过研究如何通过C#WebBrowser获取JavaScript中定义的变量,这就是我发现的:
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Net;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;
using mshtml;
namespace Mynamespace
{
public partial class Form1 : Form
{
public WebBrowser WebBrowser1 = new WebBrowser();
private void Form1_Load(object sender, EventArgs e)
{
string myurl = "http://somewebsite.com"; //Using WebBrowser control to load web page
this.WebBrowser1.Navigate(myurl);
}
private void btnGetValueFromJs_Click(object sender, EventArgs e)
{
var mydoc = this.WebBrowser1.Document;
IHTMLDocument2 vDocument = mydoc.DomDocument as IHTMLDocument2;
IHTMLWindow2 vWindow = (IHTMLWindow2)vDocument.parentWindow;
Type vWindowType = vWindow.GetType();
object strfromJS = vWindowType.InvokeMember("mystr",
BindingFlags.GetProperty, null, vWindow, new object[] { });
//Here, I am able to see the string "Hello Sir"
object gonfromJS = vWindowType.InvokeMember("gon",
BindingFlags.GetProperty, null, vWindow, new object[] { });
//Here, I am able to see the object gonfromJS as a '{System.__ComObject}'
object gonbooksfromJS = vWindowType.InvokeMember("gon.books_jsonarray",
BindingFlags.GetProperty, null, vWindow, new object[] { });
//This error is thrown: 'An unhandled exception of type 'System.Runtime.InteropServices.COMException' occurred in mscorlib.dll; (Exception from HRESULT: 0x80020006 (DISP_E_UNKNOWNNAME))'
}
}
}
我能够检索字符串或数字变量的值,例如:
var mystr = "Hello Sir";
var mynbr = 8;
但是,即使我能够看到'gon'变量作为'{System .__ ComObject}'传递,我也不知道如何解析它以查看其子组件的值.如果我可以解析它会很好,但如果没有,我想要的是一个C#数据结构,其中的键/值包含gon变量的所有子信息,尤其是能够查看变量'gon.books_jsonarray'.
任何有关如何实现这一目标的帮助将非常感激.请注意,我无论如何都无法更改源html/javascript,因此,我需要的是一个C#代码,可以实现我的目标.
您可以将 InvokeMember() 的结果强制转换为动态结果，并直接在 C# 代码中使用属性名称。数组索引很棘手，但可以通过 InvokeScript() 的另一种用法来完成，请参阅我的示例：
private void btnGetValueFromJs_Click(object sender, EventArgs e)
{
var mydoc = this.WebBrowser1.Document;
IHTMLDocument2 vDocument = mydoc.DomDocument as IHTMLDocument2;
IHTMLWindow2 vWindow = (IHTMLWindow2)vDocument.parentWindow;
Type vWindowType = vWindow.GetType();
var gonfromJS = (dynamic)vWindowType.InvokeMember("gon",
BindingFlags.GetProperty, null, vWindow, new object[] { });
var length = gonfromJS.books_jsonarray.length;
for (var i = 0; i < length; ++i)
{
var book = (dynamic) mydoc.InvokeScript("eval", new object[] { "gon.books_jsonarray[" + i + "]" });
Console.WriteLine(book.title);
/* prints:
* Little Sun
* Little Prairie
* Little World
*/
}
}