C# API 传地址的例子

最新推荐文章于 2023-02-15 23:11:42 发布

原创最新推荐文章于 2023-02-15 23:11:42 发布 · 497 阅读

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文章标签：

#c# #api #textbox #button #object #user

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本文介绍了一个使用C#实现的窗口枚举技术示例，通过枚举所有顶级窗口并获取其标题来查找特定窗口句柄的方法。该技术利用了WNDENUMPROC委托及user32.dll中的EnumWindows函数。

/// Return Type: BOOL->int
///param0: HWND->HWND__*
///param1: LPARAM->LONG_PTR->int
[System.Runtime.InteropServices.UnmanagedFunctionPointerAttribute(System.Runtime.InteropServices.CallingConvention.StdCall)]
public delegate int WNDENUMPROC(System.IntPtr param0, ref System.IntPtr param1);

//在向导生成的定义中增加ref

/// Return Type: BOOL->int
///lpEnumFunc: WNDENUMPROC
///lParam: LPARAM->LONG_PTR->int
[System.Runtime.InteropServices.DllImportAttribute("user32.dll", EntryPoint = "EnumWindows")]
[return: System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.Bool)]
public static extern bool EnumWindows(WNDENUMPROC lpEnumFunc, ref int lParam);

//在向导生成的定义中增加ref

int find(System.IntPtr param0, ref System.IntPtr param1)
{
StringBuilder s = new StringBuilder(256);

if ((int)param1 == 0)
NativeMethods.GetWindowTextA(param0, s, s.Capacity);

if ((int)param1 == 1)
NativeMethods.GetWindowTextW(param0, s, s.Capacity);

    if (s.ToString().Trim().IndexOf(textBox1.Text.Trim() ) != -1)
    {
          //解释成：将param0的值给param1地址指向的位置
          param1=param0;

return 0;
}

return 1;
}

private void button3_Click(object sender, EventArgs e)
{
WNDENUMPROC findproc = new WNDENUMPROC(find);

int h = 0;

     System.IntPtr hMainWnd;
     if (NativeMethods.EnumWindows(findproc, ref h) == false)
     {
          hMainWnd =(System.IntPtr) h;
          MessageBox.Show(hMainWnd.ToString());
     }
     else
         MessageBox.Show("No found");