使用WebDriver，Nunit和C＃测试具有不同选项的多个浏览器时，出现OpenQA.Selenium.DriverServiceNotFoundException错误。

Question

这是我用于跨浏览器测试的代码的框架。当我运行代码时，它会给我OpenQA.Selenium.DriverServiceNotFoundException错误

using NUnit.Framework;
using OpenQA.Selenium;
using OpenQA.Selenium.Firefox;
using OpenQA.Selenium.IE;
using OpenQA.Selenium.Chrome;

namespace MultipleBrowserTesting

{
[TestFixture(typeof(FirefoxDriver))]
[TestFixture(typeof(ChromeDriver))]
[TestFixture(typeof(InternetExplorerDriver))]
public class BlogTest<TWebDriver> where TWebDriver : IWebDriver, new()
{
    private IWebDriver _driver;

[Test]
public void Can_Visit_Google()
{
    _driver = new TWebDriver();

    // Navigate
    _driver.Manage().Window.Maximize();
    _driver.Navigate().GoToUrl("http://www.google.com/");
}

[TestFixtureTearDown]
public void FixtureTearDown()
{
    if (_driver != null) 
        _driver.Close();
}
}
}