Whycom;Akira;依然是EnumWindows,EnumDesktopWIndows的有关问题

Whycom;Akira;依然是EnumWindows,EnumDesktopWIndows的问题
首先要感谢两位的指点,也希望我们的问题能帮助很多迷惑的开发或入门人员.
修正后的代码运行发现不能enum桌面所有窗体,
运行result=EnumDesktopWindows(Desk,ewp,0);后使用GetLastError发现error code 为6,
如果使用Enumwindows只执行了1次就结束了,但桌面的窗口一个没有抓到
即handle is invalid
绿色的就是修正后的代码,目的是为了获取桌面所有窗口的标题
#pragma once 
namespace EnumWindow { 

using namespace System; 
using namespace System::ComponentModel; 
using namespace System::Collections; 
using namespace System::Windows::Forms; 
using namespace System::Data; 
using namespace System::Drawing; 
using namespace System::Runtime::InteropServices ;
/// <summary> 
/// Form1 摘要 
/// 
/// 警告: 如果更改此类的名称，则需要更改 
/// 与此类所依赖的所有 .resx 文件关联的托管资源编译器工具的 
/// “资源文件名”属性。否则， 
/// 设计器将不能与此窗体的关联 
/// 本地化资源正确交互。 
/// </summary> 
  delegate int EnumWndProc(System::IntPtr wnd,int LPARAM); public ref class Form1 : public System::Windows::Forms::Form 
{ 

[DllImport("user32.dll")]
static public int EnumWindows(EnumWndProc^ ep,int LPARAM);
[DllImport("user32.dll")]
static public long GetDesktopWindow(void);
[DllImport("user32.dll")]
static public bool EnumDesktopWindows(long hwnd,EnumWndProc^ ep,int LPARAM);
[DllImport("user32.dll")]
static public int GetWindowText(System::IntPtr hwnd,char* name,int COUNT);
[DllImport("Kernel32.dll")]
static public long GetLastError(void);
public: 
Form1(void) 
{ 
InitializeComponent(); 
// 
//TODO: 在此处添加构造函数代码 
// 
} 

protected: 
/// <summary> 
/// 清理所有正在使用的资源。 
/// </summary> 
~Form1() 
{ 
if (components) 
{ 
delete components; 
} 
} 
private: System::Windows::Forms::ListBox^ listBox1; 
protected:  

private: 
/// <summary> 
/// 必需的设计器变量。 
/// </summary> 
System::ComponentModel::Container ^components; 

#pragma region Windows Form Designer generated code 
/// <summary> 
/// 设计器支持所需的方法 - 不要 
/// 使用代码编辑器修改此方法的内容。 
/// </summary> 
void InitializeComponent(void) 
{ 
this-> listBox1 = (gcnew System::Windows::Forms::ListBox()); 
this-> SuspendLayout(); 
//  
// listBox1 
//  
this-> listBox1-> FormattingEnabled = true; 
this-> listBox1-> ItemHeight = 12; 
this-> listBox1-> Location = System::Drawing::Point(43, 33); 
this-> listBox1-> Name = L"listBox1"; 
this-> listBox1-> Size = System::Drawing::Size(221, 76); 
this-> listBox1-> TabIndex = 0; 
//  
// Form1 
//  
this-> AutoScaleDimensions = System::Drawing::SizeF(6, 12); 
this-> AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font; 
this-> ClientSize = System::Drawing::Size(292, 266); 
this-> Controls-> Add(this-> listBox1); 
this-> Name = L"Form1"; 
this-> Text = L"Form1"; 
this-> Load += gcnew System::EventHandler(this, &Form1::Form1_Load); 
this-> ResumeLayout(false); 

}