为什么我可以将 IWebDriver 转换为 IJavaScriptExecutor？答案

【问题标题】：How come I can cast IWebDriver to IJavaScriptExecutor?为什么我可以将 IWebDriver 转换为 IJavaScriptExecutor？
【发布时间】：2014-05-31 11:30:37
【问题描述】：

谁能解释一下这个“魔法”？

public interface IWebDriver : ISearchContext, IDisposable
{
    string CurrentWindowHandle { get; }
    string PageSource { get; }
    string Title { get; }
    string Url { get; set; }
    ReadOnlyCollection<string> WindowHandles { get; }

    void Close();
    IOptions Manage();
    INavigation Navigate();
    void Quit();
    ITargetLocator SwitchTo();
}

public interface ISearchContext
{
    IWebElement FindElement(By by);
    ReadOnlyCollection<IWebElement> FindElements(By by);
}

public interface IJavaScriptExecutor
{
    object ExecuteAsyncScript(string script, params object[] args);
    object ExecuteScript(string script, params object[] args);
}

怎么来的

(this.Driver as IJavaScriptExecutor).ExecuteScript("console.log('wtf?')");

工作正常吗？

【问题讨论】：

标签： c# javascript .net inheritance selenium

【解决方案1】：

是的，默认实现是这样的，当演员发生时它实际上是IWebDriver-> ChromeDriver -> RemoteWebDriver -> IJavaScriptExecutor

public class RemoteWebDriver : IWebDriver, IDisposable, ISearchContext, IJavaScriptExecutor, IFindsById, IFindsByClassName, IFindsByLinkText, IFindsByName, IFindsByTagName, IFindsByXPath, IFindsByPartialLinkText, IFindsByCssSelector, IHasInputDevices, IHasCapabilities, IAllowsFileDetection
{
    protected static readonly TimeSpan DefaultCommandTimeout;

    public RemoteWebDriver(ICapabilities desiredCapabilities);
    public RemoteWebDriver(ICommandExecutor commandExecutor, ICapabilities desiredCapabilities);
    public RemoteWebDriver(Uri remoteAddress, ICapabilities desiredCapabilities);
    public RemoteWebDriver(Uri remoteAddress, ICapabilities desiredCapabilities, TimeSpan commandTimeout);

    public ICapabilities Capabilities { get; }
    protected ICommandExecutor CommandExecutor { get; }
    public string CurrentWindowHandle { get; }
    public virtual IFileDetector FileDetector { get; set; }
    public IKeyboard Keyboard { get; }
    public IMouse Mouse { get; }
    public string PageSource { get; }
    protected SessionId SessionId { get; }
    public string Title { get; }
    public string Url { get; set; }
    public ReadOnlyCollection<string> WindowHandles { get; }

    public void Close();
    protected virtual RemoteWebElement CreateElement(string elementId);
    public void Dispose();
    protected virtual void Dispose(bool disposing);
    protected virtual Response Execute(string driverCommandToExecute, Dictionary<string, object> parameters);
    public object ExecuteAsyncScript(string script, params object[] args);
    public object ExecuteScript(string script, params object[] args);
    public IWebElement FindElement(By by);
    protected IWebElement FindElement(string mechanism, string value);
    public IWebElement FindElementByClassName(string className);
    public IWebElement FindElementByCssSelector(string cssSelector);
    public IWebElement FindElementById(string id);
    public IWebElement FindElementByLinkText(string linkText);
    public IWebElement FindElementByName(string name);
    public IWebElement FindElementByPartialLinkText(string partialLinkText);
    public IWebElement FindElementByTagName(string tagName);
    public IWebElement FindElementByXPath(string xpath);
    public ReadOnlyCollection<IWebElement> FindElements(By by);
    protected ReadOnlyCollection<IWebElement> FindElements(string mechanism, string value);
    public ReadOnlyCollection<IWebElement> FindElementsByClassName(string className);
    public ReadOnlyCollection<IWebElement> FindElementsByCssSelector(string cssSelector);
    public ReadOnlyCollection<IWebElement> FindElementsById(string id);
    public ReadOnlyCollection<IWebElement> FindElementsByLinkText(string linkText);
    public ReadOnlyCollection<IWebElement> FindElementsByName(string name);
    public ReadOnlyCollection<IWebElement> FindElementsByPartialLinkText(string partialLinkText);
    public ReadOnlyCollection<IWebElement> FindElementsByTagName(string tagName);
    public ReadOnlyCollection<IWebElement> FindElementsByXPath(string xpath);
    public IOptions Manage();
    public INavigation Navigate();
    public void Quit();
    protected virtual void StartClient();
    protected void StartSession(ICapabilities desiredCapabilities);
    protected virtual void StopClient();
    public ITargetLocator SwitchTo();
}

【讨论】：

【解决方案2】：

这是因为IWebDriver 的main implementation implements IJavaScriptExecutor 提供了实现of those methods。

您尚未提供显示如何实例化驱动程序的代码，但它们都继承自 RemoteWebDriver：示例是 ChromeDriver

【讨论】：