悬浮穿透文字

        private void Form1_Load(object sender, EventArgs e)
        {
            var transColor = Color.Red;
            this.BackColor = transColor;
            this.TransparencyKey = transColor;
            this.FormBorderStyle = FormBorderStyle.None;
            this.ShowInTaskbar = false;
            this.TopMost = true;
            label1.BackColor = transColor;
            label1.Text = "这是悬浮穿透文字";
        }

 上方仍然有一个缺点，在Win7下点击任务栏或者开始按钮时仍然可能展示到后面去，可以加一个Timer来定时设置this.TopMost = true;