我正在尝试通过 UI 自动化对我的应用程序进行自动化测试（主要TestStack.White用于提供友好的界面；它System.Windows.Automation用作后端）。我有一个大约 200 行的表，我需要测试它的值（实际上我只想测试第一行和最后几行）。我发现单独使用 COM-interop UIAutomationCore，我可以在几分之一秒内枚举行，但前提是我不使用 White 或System.Windows.Automation. 一旦System.Windows.Automation初始化，未来枚举行的 UI 自动化操作就会很慢：
First COM run: it took 0.04 seconds to get 102 rows!
First System.Windows.Automation run: it took 7.18 seconds to get 102 rows!
Second COM run: it took 7.87 seconds to get 102 rows!
我创建了一个简单的 WinForms 测试应用程序（TableTest.exe以验证它是否System.Windows.Automation与我的应用程序无关：
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
var form = new Form() { Text = "TableTest", WindowState = FormWindowState.Maximized };
var dgv = new DataGridView() { Name = "DGV", Dock = DockStyle.Fill, AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill };
dgv.Columns.Add("i", "i");
dgv.Columns.Add("2i", "2i");
dgv.Columns.Add("i^2", "i^2");
dgv.Columns.Add("i^i", "i^i");
for (int i = 0; i < 100; ++i)
dgv.Rows.Add(i, i * 2, i * i, Math.Pow(i, i));
form.Controls.Add(dgv);
Application.Run(form);
}
然后我创建了另一个测试应用程序来测试第一个。它可以用作控制台应用程序或 WinForms 应用程序。首先我使用 COM 自动化进行测试，然后使用 System.Windows.Automation 进行测试，然后再次使用 COM 自动化进行测试。从我上面引用的输出中可以看出，第一个块执行得非常快，接下来的两个块执行得非常慢。如果我注释掉System.Windows.Automation块代码，那么两个 COM 块都会快速执行。
using UIA = Interop.UIAutomationCore;
static void Main(string[] args)
{
var process = System.Diagnostics.Process.Start("TableTest.exe");
System.Threading.Thread.Sleep(500);
var uia = new UIA.CUIAutomation();
var rootCom = uia.GetRootElement();
var windowCom = rootCom.FindFirst(UIA.TreeScope.TreeScope_Children, uia.CreatePropertyCondition(UIA.UIA_PropertyIds.UIA_NamePropertyId, "TableTest"));
var dgvCom = windowCom.FindFirst(UIA.TreeScope.TreeScope_Descendants, uia.CreatePropertyCondition(UIA.UIA_PropertyIds.UIA_AutomationIdPropertyId, "DGV"));
var start = DateTime.Now;
var rowCount = dgvCom.FindAll(UIA.TreeScope.TreeScope_Children, uia.CreatePropertyCondition(UIA.UIA_PropertyIds.UIA_ControlTypePropertyId, UIA.UIA_ControlTypeIds.UIA_CustomControlTypeId)).Length;
var elapsed = (DateTime.Now - start).TotalSeconds;
Console.WriteLine(String.Format("It took {0} seconds to get {1} rows!", elapsed.ToString("f2"), rowCount));
process.Kill();
process = System.Diagnostics.Process.Start("TableTest.exe");
System.Threading.Thread.Sleep(500);
var root = AutomationElement.RootElement;
var window = root.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, "TableTest"));
var dgv = window.FindFirst(TreeScope.Descendants, new PropertyCondition(AutomationElement.AutomationIdProperty, "DGV"));
start = DateTime.Now;
rowCount = dgv.FindAll(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Custom)).Count;
elapsed = (DateTime.Now - start).TotalSeconds;
Console.WriteLine(String.Format("It took {0} seconds to get {1} rows!", elapsed.ToString("f2"), rowCount));
process.Kill();
process = System.Diagnostics.Process.Start("TableTest.exe");
System.Threading.Thread.Sleep(500);
uia = new UIA.CUIAutomation();
rootCom = uia.GetRootElement();
windowCom = rootCom.FindFirst(UIA.TreeScope.TreeScope_Children, uia.CreatePropertyCondition(UIA.UIA_PropertyIds.UIA_NamePropertyId, "TableTest"));
dgvCom = windowCom.FindFirst(UIA.TreeScope.TreeScope_Descendants, uia.CreatePropertyCondition(UIA.UIA_PropertyIds.UIA_AutomationIdPropertyId, "DGV"));
start = DateTime.Now;
rowCount = dgvCom.FindAll(UIA.TreeScope.TreeScope_Children, uia.CreatePropertyCondition(UIA.UIA_PropertyIds.UIA_ControlTypePropertyId, UIA.UIA_ControlTypeIds.UIA_CustomControlTypeId)).Length;
elapsed = (DateTime.Now - start).TotalSeconds;
Console.WriteLine(String.Format("It took {0} seconds to get {1} rows!", elapsed.ToString("f2"), rowCount));
process.Kill();
}
到底是System.Windows.Automation什么在扼杀 UI 自动化的性能？我查看了 White 源代码，但没有看到任何明显的东西。我无法分析 System.Windows.Automation 本身，因为我找不到任何 PDB。我对 UI 自动化不是很熟悉，所以也许对其他人来说很明显。白色是：0.13.0.0我正在 64 位 Windows 7 上进行测试。