Windows UI自动化

Question

我正在测试以下示例代码,并且每当我尝试运行它时,我将在下面显示错误.但是,calc.exe进程是成功执行的,那么句柄如何可能为null或为零？我希望你能理解我想要解决的问题.谢谢!代码示例来自http://www.mathpirate.net/log/tag/system-windows-automation/

UIAutomationClient.dll中发生未处理的"System.ArgumentException"类型异常附加信息:hwnd不能是IntPtr.Zero或null.

//Launches the Windows Calculator and gets the Main Window's Handle.
Process calculatorProcess = Process.Start("calc.exe");
calculatorProcess.WaitForInputIdle();
IntPtr calculatorWindowHandle = calculatorProcess.MainWindowHandle;

//Here I use a window handle to get an AutomationElement for a specific window.
AutomationElement calculatorElement = AutomationElement.FromHandle(calculatorWindowHandle);

if(calculatorElement == null)
{
    throw new Exception("Uh-oh, couldn't find the calculator...");
}

//Walks some of the more interesting properties on the AutomationElement.
Console.WriteLine("--------Element");
Console.WriteLine("AutomationId: {0}", calculatorElement.Current.AutomationId);
Console.WriteLine("Name: {0}", calculatorElement.Current.Name);
Console.WriteLine("ClassName: {0}", calculatorElement.Current.ClassName);
Console.WriteLine("ControlType: {0}", calculatorElement.Current.ControlType.ProgrammaticName);
Console.WriteLine("IsEnabled: {0}", calculatorElement.Current.IsEnabled);
Console.WriteLine("IsOffscreen: {0}", calculatorElement.Current.IsOffscreen);
Console.WriteLine("ProcessId: {0}", calculatorElement.Current.ProcessId);

//Commented out because it requires another library reference. However, it's useful to see that this exists.
//Console.WriteLine("BoundingRectangle: {0}", calculatorElement.Current.BoundingRectangle);

Console.WriteLine("Supported Patterns:");
foreach (AutomationPattern supportedPattern in calculatorElement.GetSupportedPatterns())
{
    Console.WriteLine("\t{0}", supportedPattern.ProgrammaticName);
}

Answer 1

您误解了WaitForInputIdle（对于该函数当前的功能来说，这是一个非常糟糕的名字）。您甚至在创建主窗口之前就询问主窗口的地址。结果，您最终将无效的窗口句柄传递给其他函数。

编辑：我强烈建议使用 UI 自动化库，例如white如果您要使用它进行认真的工作。