c# 調用User32.dll

獲取當前窗口句柄:GetForegroundWindow()
[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern IntPtr GetForegroundWindow();

使用方法   IntPtr myPtr=GetForegroundWindow();

  [DllImport("kernel32.dll")]
   static extern IntPtr LoadLibrary(string lpFileName);

   [DllImport("kernel32.dll", SetLastError = true)]
   static extern bool FreeLibrary(IntPtr hModule);
      // <summary>

         /// Loadlibrary 返回的函數庫模塊的句柄

         /// </summary>

         private  IntPtr hModule = IntPtr.Zero;

　　　  /// <summary>
        /// 裝載 Dll
        /// </summary>
        /// <param name="lpFileName">DLL 文件名 </param>
        public void LoadDll(string lpFileName)
        {
            hModule = LoadLibrary(lpFileName);
            if (hModule == IntPtr.Zero)
            {
                throw (new Exception(" 沒有找到 :" + lpFileName + "."));
            }
        }

                   /// <summary> 
          
        /// 卸載 Dll 
          
        /// </summary> 
          
        public void UnLoadDll() 
          
        { 
          
            FreeLibrary(hModule); 
          
            hModule = IntPtr.Zero; 
         

        }