通过timer控件和窗体的opacity属性，轻松实现窗体的淡入淡出

窗体加载#region 窗体加载
                private void Form1_Load(object sender, EventArgs e)
                {
                        //timer控件ShowForm1
                        this.ShowForm1.Enabled = true; //控件是否激活
                        this.ShowForm1.Interval = 100; //Elapsed 事件的频率
                        //timer控件HideForm1
                        this.HideForm1.Enabled = false;
                        this.HideForm1.Interval = 100;
                        this.Opacity = 0.5;    //设置窗体透明度
                        ShowForm1.Start();    //timer控件 ShowForm1开始
                }
                #endregion
                    
打开form1#region 打开form1
                private void ShowForm1_Tick(object sender, EventArgs e)
                {
                        if (this.Opacity == 1)    //如果窗体透明度达到 1
                        {
                                this.ShowForm1.Stop();
                        }
                        else    //透明度小于 1
                        {
                                this.Opacity = this.Opacity + 0.1; //透明度递增
                                
                        }
                }
                #endregion
隐藏from1#region 隐藏from1
                private void HideForm1_Tick_1(object sender, EventArgs e)
                {
                        this.Opacity = this.Opacity - 0.1; //透明度不等于 0
                        if (this.Opacity == 0) //透明度等于 0
                        {
                                this.HideForm1.Stop();
                                this.Hide();
                                                                
                        }
                }
                #endregion                
关闭#region 关闭
                private void button1_Click(object sender, EventArgs e)
                {
                        this.HideForm1.Start();
                }
                #endregion