c# - CreateWindowEx 和 RegisterClass C#

Question

我想创建一个新类，然后显示一个包含指定类的窗口。我为此编写了以下代码:

    namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        [DllImport("user32.dll")]
        static extern bool UpdateWindow(IntPtr hWnd);

        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
        [DllImport("user32.dll", SetLastError = true, EntryPoint = "CreateWindowEx")]
        public static extern IntPtr CreateWindowEx(
           int dwExStyle,
           string lpClassName,
           string lpWindowName,
           int dwStyle,
           int x,
           int y,
           int nWidth,
           int nHeight,
           IntPtr hWndParent,
           IntPtr hMenu,
           IntPtr hInstance,
           IntPtr lpParam);
        [System.Runtime.InteropServices.DllImport("user32.dll", SetLastError = true)]
        static extern System.UInt16 RegisterClassW(
            [System.Runtime.InteropServices.In] ref WNDCLASSEX lpWndClass
        );
        struct WNDCLASSEX
        {
            [MarshalAs(UnmanagedType.U4)]
            public int cbSize;
            [MarshalAs(UnmanagedType.U4)]
            public int style;
            public IntPtr lpfnWndProc; // not WndProc
            public int cbClsExtra;
            public int cbWndExtra;
            public IntPtr hInstance;
            public IntPtr hIcon;
            public IntPtr hCursor;
            public IntPtr hbrBackground;
            public string lpszMenuName;
            public string lpszClassName;
            public IntPtr hIconSm;
        }
        [DllImport("user32.dll")]
        static extern IntPtr DefWindowProc(IntPtr hWnd, uint uMsg, IntPtr wParam, IntPtr lParam);

        public Form1()
        {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e)
        {


        }

        private void button1_Click(object sender, EventArgs e)
        {
            WNDCLASSEX wind_class = new WNDCLASSEX();
            wind_class.cbSize = Marshal.SizeOf(typeof(WNDCLASSEX));
            wind_class.style = 0x00020000;
            wind_class.hbrBackground = (IntPtr) 5;
            wind_class.cbClsExtra = 0;
            wind_class.cbWndExtra = 0;
            wind_class.hInstance = Marshal.GetHINSTANCE(GetType().Module);
            wind_class.hIcon = this.Icon.Handle;
            wind_class.hCursor = IntPtr.Zero;
            wind_class.lpszMenuName = string.Empty;
            wind_class.lpszClassName = "MyClass";
            wind_class.lpfnWndProc = DefWindowProc(IntPtr.Zero, 0, IntPtr.Zero, IntPtr.Zero);
            RegisterClassW(ref wind_class);
            IntPtr lolo = CreateWindowEx(0, "MyClass", "MyClass",0,0,0,30,40,IntPtr.Zero,IntPtr.Zero,IntPtr.Zero,IntPtr.Zero);
            ShowWindow(lolo, 1);
            UpdateWindow(lolo);
        }
    }
}

但它无法正常工作。它不显示窗口。当我用我的类名用 Spy++ 搜索时，它找不到任何结果..

我在网络上搜索并在我的代码中做了一些编辑，但它们没有用。

我的问题在哪里!？

问候。

Answer 1

普通的 Win32 与 Win32 C 相比毫无乐趣，与 .NET 相比也不那么有趣。但无论如何，它可能在极少数情况下有用。这里有一个 C# 类，它应该做你想做的事。首先，对您的软件进行一般性说明。在 Win32 中，您应该始终检查系统调用的返回码，如果出现错误，请调用 GetLastError() 以获取有关失败的更详细信息。如果您检查了 RegisterClass 函数的结果但它失败了，您就会知道如果不修复该函数就无法继续。

以下是一个可以用作进一步研究模板的类，它应该可以成功注册并创建一个可调整大小的窗口。此外，一些简单的操作(如双击)在自定义窗口过程中进行处理。对于代码的某些部分，请转到 this该网站是我在网络上发现的少数几个展示有效内容的网站之一。

CreateWindowEx 很棘手，因为您不能将字符串作为类名，而是 RegisterClassEx 的结果。使用的常量主要在 C 头文件 winuser.h 中找到。为了能够用这种方法做一些有用的事情，主要的绘画必须“手工”完成，通过适本地操作设备上下文是一项繁琐而乏味的工作。当然，这一切都不会出现在下面的例子中。可以调用类的“创建”方法，例如从 Windows 窗体按钮单击。命名空间名称当然是任意选择的。 WinForm 项目是 x86 32 位、.NET 4.0。

玩得开心!

namespace Win32FromForms
{
    delegate IntPtr WndProc(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);

    class Win32Window
    {
        const UInt32 WS_OVERLAPPEDWINDOW = 0xcf0000;
        const UInt32 WS_VISIBLE = 0x10000000;
        const UInt32 CS_USEDEFAULT = 0x80000000;
        const UInt32 CS_DBLCLKS = 8;
        const UInt32 CS_VREDRAW = 1;
        const UInt32 CS_HREDRAW = 2;
        const UInt32 COLOR_WINDOW = 5;
        const UInt32 COLOR_BACKGROUND = 1;
        const UInt32 IDC_CROSS = 32515;
        const UInt32 WM_DESTROY = 2;
        const UInt32 WM_PAINT = 0x0f;
        const UInt32 WM_LBUTTONUP = 0x0202;
        const UInt32 WM_LBUTTONDBLCLK = 0x0203;

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        struct WNDCLASSEX
        {
            [MarshalAs(UnmanagedType.U4)]
            public int cbSize;
            [MarshalAs(UnmanagedType.U4)]
            public int style;
            public IntPtr lpfnWndProc; 
            public int cbClsExtra;
            public int cbWndExtra;
            public IntPtr hInstance;
            public IntPtr hIcon;
            public IntPtr hCursor;
            public IntPtr hbrBackground;
            public string lpszMenuName;
            public string lpszClassName;
            public IntPtr hIconSm;
        }


        private WndProc delegWndProc = myWndProc;

        [DllImport("user32.dll")]
        static extern bool UpdateWindow(IntPtr hWnd);

        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

        [System.Runtime.InteropServices.DllImport("user32.dll", SetLastError = true)]
        static extern bool DestroyWindow(IntPtr hWnd);


        [DllImport("user32.dll", SetLastError = true, EntryPoint = "CreateWindowEx")]
        public static extern IntPtr CreateWindowEx(
           int dwExStyle,
           UInt16 regResult,
           //string lpClassName,
           string lpWindowName,
           UInt32 dwStyle,
           int x,
           int y,
           int nWidth,
           int nHeight,
           IntPtr hWndParent,
           IntPtr hMenu,
           IntPtr hInstance,
           IntPtr lpParam);

        [DllImport("user32.dll", SetLastError = true, EntryPoint = "RegisterClassEx")]
        static extern System.UInt16 RegisterClassEx([In] ref WNDCLASSEX lpWndClass);

        [DllImport("kernel32.dll")]
        static extern uint GetLastError();

        [DllImport("user32.dll")]
        static extern IntPtr DefWindowProc(IntPtr hWnd, uint uMsg, IntPtr wParam, IntPtr lParam);

        [DllImport("user32.dll")]
        static extern void PostQuitMessage(int nExitCode);

        //[DllImport("user32.dll")]
        //static extern sbyte GetMessage(out MSG lpMsg, IntPtr hWnd, uint wMsgFilterMin,
        //   uint wMsgFilterMax);

        [DllImport("user32.dll")]
        static extern IntPtr LoadCursor(IntPtr hInstance, int lpCursorName);

        [DllImport("user32.dll")]
        static extern bool TranslateMessage([In] ref MSG lpMsg);

        [DllImport("user32.dll")]
        static extern IntPtr DispatchMessage([In] ref MSG lpmsg);    


        internal bool create()
        {
            WNDCLASSEX wind_class = new WNDCLASSEX();
            wind_class.cbSize = Marshal.SizeOf(typeof(WNDCLASSEX));
            wind_class.style = (int)(CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS ) ; //Doubleclicks are active
            wind_class.hbrBackground = (IntPtr) COLOR_BACKGROUND  +1 ; //Black background, +1 is necessary
            wind_class.cbClsExtra = 0;
            wind_class.cbWndExtra = 0;
            wind_class.hInstance = Marshal.GetHINSTANCE(this.GetType().Module); ;// alternative: Process.GetCurrentProcess().Handle;
            wind_class.hIcon = IntPtr.Zero;
            wind_class.hCursor = LoadCursor(IntPtr.Zero, (int)IDC_CROSS);// Crosshair cursor;
            wind_class.lpszMenuName = null;
            wind_class.lpszClassName = "myClass";
            wind_class.lpfnWndProc = Marshal.GetFunctionPointerForDelegate(delegWndProc);
            wind_class.hIconSm = IntPtr.Zero;
            ushort regResult = RegisterClassEx(ref wind_class);

            if (regResult == 0)
            {
                uint error = GetLastError();
                return false;
            }
            string wndClass = wind_class.lpszClassName;

            //The next line did NOT work with me! When searching the web, the reason seems to be unclear! 
            //It resulted in a zero hWnd, but GetLastError resulted in zero (i.e. no error) as well !!??)
            //IntPtr hWnd = CreateWindowEx(0, wind_class.lpszClassName, "MyWnd", WS_OVERLAPPEDWINDOW | WS_VISIBLE, 0, 0, 30, 40, IntPtr.Zero, IntPtr.Zero, wind_class.hInstance, IntPtr.Zero);

            //This version worked and resulted in a non-zero hWnd
            IntPtr hWnd = CreateWindowEx(0, regResult, "Hello Win32", WS_OVERLAPPEDWINDOW | WS_VISIBLE, 0, 0, 300, 400, IntPtr.Zero, IntPtr.Zero, wind_class.hInstance, IntPtr.Zero);

            if (hWnd == ((IntPtr)0))
            {
                uint error = GetLastError();
                return false;
            }
            ShowWindow(hWnd, 1);
            UpdateWindow(hWnd);
            return true;

            //The explicit message pump is not necessary, messages are obviously dispatched by the framework.
            //However, if the while loop is implemented, the functions are called... Windows mysteries...
            //MSG msg;
            //while (GetMessage(out msg, IntPtr.Zero, 0, 0) != 0)
            //{
            //    TranslateMessage(ref msg);
            //    DispatchMessage(ref msg);
            //}
        }

        private static IntPtr myWndProc(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam)
        {
            switch (msg)
            {
                // All GUI painting must be done here
                case WM_PAINT:
                    break;

                case WM_LBUTTONDBLCLK :
                    MessageBox.Show("Doubleclick");
                    break;

                case WM_DESTROY:
                    DestroyWindow(hWnd);

                    //If you want to shutdown the application, call the next function instead of DestroyWindow
                    //PostQuitMessage(0);
                    break;

                default:
                    break;
            }
            return DefWindowProc(hWnd, msg, wParam, lParam);
        }
    }
}