winform窗体透明背景实现 因为winform Form窗体的局限性，不允许设置背景色为transparent。所以不能实现透明背景。这里有一个取巧的方法（截Form后的背景）。首先来看下实现效果： 想要实现半透明效果只要加个panel ,将panel设置为背景色透明，然后加个遮罩图片就可以了。 以下附上实现代码：using System; using System.Drawing; using System.Windows.Forms; namespace WindowsTrans { public partial class Form1 : Form { private Color tr_color = Color.Transparent; private bool b_start = false; bool[] b_visible = null; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { SetBackgroundImageTransparent(); } private void SetBackgroundImageTransparent() { Point pt = this.PointToScreen(new Point(0, 0)); Bitmap b = new Bitmap(this.Width, this.Height); using (Graphics g = Graphics.FromImage(b)) { g.CopyFromScreen(pt, new Point(), new Size(this.Width, this.Height)); } this.BackgroundImage = b; } private void BeginSet() { tr_color = this.TransparencyKey; b_start = true; } private void Setting() { if (b_start) { b_visible = new bool[Controls.Count]; for (int i = 0; i < Controls.Count; i++) { b_visible[i] = Controls[i].Visible; Controls[i].Visible = false; } BackgroundImage = null; BackColor = Color.White; b_start = false; this.TransparencyKey = Color.White; } } private void EndSet() { SetBackgroundImageTransparent(); this.TransparencyKey = tr_color; for (int i = 0; i < Controls.Count; i++) { Controls[i].Visible = b_visible[i]; } b_start = false; } private void Form1_Resize(object sender, EventArgs e) { Setting(); } private void Form1_ResizeBegin(object sender, EventArgs e) { BeginSet(); } private void Form1_ResizeEnd(object sender, EventArgs e) { EndSet(); } private void Form1_Move(object sender, EventArgs e) { Setting(); } } }