用户控件，Paint事件中去除背景

Question

在用户控件中，我想实现不同的图像，比如　圆形，　矩形　三角形　等等，这些形状只占用用户控件可见区域的一部分，其余空白部分，以透明形式存在，我想问的是 gdi+ 如何实现？即　去除背景。

Answer 1

可否给出你的原来结果以及最终要的结果？

---

If you think one reply solves your problem, please mark it as An Answer, if you think someone's reply helps you, please mark it as a Proposed Answer

Help by clicking：
Click here to donate your rice to the poor
Click to Donate
Click to feed Dogs & Cats

Found any spamming-senders? Please report at: Spam Report

Answer 2

        private void UserControl1_Paint(object sender, PaintEventArgs e)
        {
            var g = e.Graphics;
            g.Clear(Color.White);
            g.SmoothingMode = SmoothingMode.HighQuality;//可以反锯齿
            var rectBound = new Rectangle(0, 0, Width-1, Height-1);
 
            var b = new SolidBrush(Color.FromArgb(0, 122, 204));
            var rect = new Rectangle(2, 2, Width - 4, Height - 4);
            if(!_isSelected)//FillRectangle
                g.FillEllipse(b, rectBound);
            else
                g.FillEllipse(b, rect);
 
            var pen = new Pen(Color.Yellow);
            pen.DashStyle = DashStyle.DashDot;
            g.DrawLine(pen,10,10,100,10);
 
            pen.DashStyle = DashStyle.Dash;
            g.DrawLine(pen, 10, 15, 100, 15);
 
            pen.DashStyle = DashStyle.DashDotDot;
            g.DrawLine(pen, 10, 20, 100, 20);
 
            pen.DashStyle = DashStyle.Dot;
            g.DrawLine(pen, 10, 25, 100, 25);
 
            pen.DashStyle = DashStyle.Solid;
            g.DrawLine(pen, 10, 30, 100, 30);
 
            if (_isSelected)
            {
                pen = new Pen(Color.Black) { DashStyle = DashStyle.Dot, Width = 1 };
                g.DrawRectangle(pen, rectBound);
            }
 
        }

Answer 3

有兄弟知道不？在线等。。。。

Answer 4

var g = e.Graphics;
            ////g.Clear(Color.White);

---

http://feiyun0112.cnblogs.com/