这个 lambda 表达式的 C# 2.0 等效代码是什么

Question

我需要一个通过打开的资源管理器窗口进行枚举的功能。这是我得到的代码：

delegate bool EnumThreadDelegate(IntPtr hWnd, IntPtr lParam);

[DllImport("user32.dll")]
static extern bool EnumThreadWindows(int dwThreadId, EnumThreadDelegate lpfn, IntPtr lParam);

static IEnumerable<IntPtr> EnumerateProcessWindowHandles(int processID)
{
    List<IntPtr> handles = new List<IntPtr>();

    foreach (ProcessThread thread in Process.GetProcessById(processID).Threads)
    {                                //what is the magic going on beneath this?? :o
        EnumThreadWindows(thread.Id, (hWnd, lParam) => { handles.Add(hWnd); return true;}, IntPtr.Zero);
    }
    return handles;
}

代码在这里继续如下：

[DllImport("coredll.dll")]
static extern int ShowWindow(IntPtr hWnd, int nCmdShow);

const int SW_MINIMIZED = 6;

private void button1_Click(object sender, EventArgs e)
{
    foreach (IntPtr handle in EnumerateProcessWindowHandles(Process.GetProcessesByName("explorer")[0].Id))
    {
        ShowWindow(handle, SW_MINIMIZED);
    }
}

我的问题是，在第一个代码块中，如何替换 lambda 表达式以便我可以在 VS 2005 中使用 C# 2.0 编译代码。

Answer 1

创建一个新方法以传递给EnumThreadWindows，如下所示：

static bool EnumThreadCallback(IntPtr hWnd, IntPtr lParam)
{
    // Close the enumerated window.
    PostMessage(hWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);

    return true;
}

并派一个代表一起去：

public delegate bool EnumThreadDelegate (IntPtr hWnd, IntPtr lParam);

然后像这样调用函数：

foreach (ProcessThread pt in proc.Threads)
{
    EnumThreadWindows((uint)pt.Id, new EnumThreadDelegate(EnumThreadCallback), IntPtr.Zero); 
}

来源：http://www.pinvoke.net/default.aspx/user32/EnumThreadWindows.html

Answer 2

delegate bool EnumThreadDelegate(IntPtr hWnd, IntPtr lParam);

static IEnumerable<IntPtr> EnumerateProcessWindowHandles(int processID)
{
    List<IntPtr> handles = new List<IntPtr>();

    EnumThreadDelegate addWindowHandle = delegate(IntPtr hWnd, IntPtr param)
    {
        handles.Add(hWnd); 
        return true;
    };

    foreach (ProcessThread thread in Process.GetProcessById(processID).Threads)
    {
        EnumThreadWindows(thread.Id, addWindowHandle, IntPtr.Zero);
    }
    return handles;
}