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尝试读取 mshtml.HTMLDocument 属性会导致以下异常：

mscorlib.dll 中出现“System.InvalidCastException”类型的未处理异常附加信息：指定的强制转换无效。发生了

这发生在“object script = doc.Script;”这一行上。

代码：

using System;
using System.Reflection;
using mshtml;
using SHDocVw;

namespace ConsoleApp12
{
    class Program
    {
        static void Main(string[] args)
        {
            string command = string.Empty;

            while (command != "exit")
            {
                Console.Write("Enter command: ");
                command = Console.ReadLine();

                if (command == "go")
                {
                    ShellWindows shellWindows = new SHDocVw.ShellWindows();
                    foreach (var shellWindow in shellWindows)
                    {
                        var ie = shellWindow as SHDocVw.InternetExplorer;
                        if (ie != null)
                        {
                            var doc = ie.Document as HTMLDocument;
                            if (doc != null)
                            {
                                if (doc.title.Contains("Test Page"))
                                {
                                    object script = doc.Script;
                                    script.GetType().InvokeMember("DoSomething", BindingFlags.InvokeMethod, null, script, null);
                                }
                            }
                        }
                    }
                }
                else
                {
                    Console.WriteLine("Unrecognized command");
                }
            }
        }
    }
}

这是我正在使用的测试页面：

<!DOCTYPE html>
<html>
<head>
  <title>Test Page</title>
</head>
<body>

<script>

function sayHello()
{
    alert('Hello');
}

</script>

<h1>My First Heading</h1>
<p>My first paragraph.</p>

</body>
</html>

这是我的项目参考：

    <Reference Include="Interop.SHDocVw">
      <HintPath>..\..\..\TestApp\lib\Interop.SHDocVw.dll</HintPath>
      <EmbedInteropTypes>True</EmbedInteropTypes>
    </Reference>
    <Reference Include="Microsoft.mshtml, Version=7.0.3300.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
      <EmbedInteropTypes>False</EmbedInteropTypes>
    </Reference>
4

1 回答 1

0

原来我需要做的就是将它作为单线程单元运行。这个答案给了我我需要的提示： https ://stackoverflow.com/a/19275241/2382032

using System;
using System.Reflection;
using System.Threading;
using mshtml;
using SHDocVw;

namespace ConsoleApp12
{
    class Program
    {
        static void Main(string[] args)
        {
            string command = string.Empty;

            while (command != "exit")
            {
                Console.Write("Enter command: ");
                command = Console.ReadLine();

                if (command == "go")
                {
                    Thread thread = new Thread(() =>
                    {
                        ShellWindows shellWindows = new SHDocVw.ShellWindows();
                        foreach (var shellWindow in shellWindows)
                        {
                            var ie = shellWindow as SHDocVw.InternetExplorer;
                            if (ie != null)
                            {
                                var doc = ie.Document as HTMLDocument;
                                if (doc != null)
                                {
                                    if (doc.title.Contains("Test Page"))
                                    {
                                        object script = doc.Script;
                                        script.GetType().InvokeMember("sayHello", BindingFlags.InvokeMethod, null, script, null);
                                    }
                                }
                            }
                        }
                    });
                    thread.SetApartmentState(ApartmentState.STA);
                    thread.Start();
                }
                else
                {
                    Console.WriteLine("Unrecognized command");
                }
            }
        }
    }
}
于 2020-05-27T01:31:24.810 回答