C#实现窗口淡入淡出效果

public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
            AnimateWindow(this.Handle, 300, AW_BLEND  + AW_VER_NEGATIVE);//初始化时候调用
            this.FormClosed += new FormClosedEventHandler(Form2_FormClosed);
        }

        void Form2_FormClosed(object sender, FormClosedEventArgs e)
        {
            AnimateWindow(this.Handle, 300, AW_BLEND + AW_VER_NEGATIVE + AW_HIDE);  //关闭WinForm时候调用
        }

        [System.Runtime.InteropServices.DllImport("user32.dll")]
        private static extern bool AnimateWindow(IntPtr hwnd, int dwTime, int dwFlags);

        //hwmd 窗口句柄 dwTime动画持续时间 DwFlags参数选项
        public const Int32 AW_HOR_POSITIVE = 0x00000001;
        public const Int32 AW_HOR_NEGATIVE = 0x00000002;
        public const Int32 AW_VER_POSITIVE = 0x00000004;
        public const Int32 AW_VER_NEGATIVE = 0x00000008;
        public const Int32 AW_CENTER = 0x00000010;
        public const Int32 AW_HIDE = 0x00010000;
        public const Int32 AW_ACTIVATE = 0x00020000;
        public const Int32 AW_SLIDE = 0x00040000;
        public const Int32 AW_BLEND = 0x00080000; 
        
        
        
    }

今天我开始写Blog咯，呵呵!
实现窗口的淡入淡出效果，要调用WINDOWS提供的API函数,不知道.NET类库有没有提供这样的函数!