C#透明窗体实现方法

namespace WindowsApplication1{  public partial class Form2 : Form  {    public Form2()    {      InitializeComponent();      this.Opacity = 1;      this.Text = "opacity=1";      this.TopMost = true;    }    private void Form2_Activated(object sender, EventArgs e)    {      this.timer1.Enabled = true;    }    private void Form2_Deactivate(object sender, EventArgs e)    {      this.timer1.Enabled = false;      this.Opacity = 1;      this.Text = "opacity=" + this.Opacity.ToString();    }    private void Form2_Load(object sender, EventArgs e)    {    }    private void timer1_Tick(object sender, EventArgs e)    {      if (this.Opacity > 0)      {        this.Opacity -= 0.1;        this.Text = "opacity=" + this.Opacity.ToString();      }      else if (this.Opacity == 0)      {        this.Close();      }      else this.timer1.Enabled = false;    }  }}