C#创建不规则窗体四种方式 01

现在，C#创建不规则窗体不是一件难事，下面总结一下:

　　一、自定义窗体，一般为规则的图形，如圆、椭圆等。

做法：重写Form1_Paint事件（Form1是窗体的名字），最简单的一种情况如下：

System.Drawing.Drawing2D.GraphicsPath shape = new System.Drawing.Drawing2D.GraphicsPath();

shape.AddEllipse(0,0,this.Height, this.Width);

this.Region = new Region(shape);

　　做法：重写Form1_Paint事件(Form1是窗体的名字)，最简单的一种情况如下：

　　即重绘窗体的规则。

　　二、利用背景图片实现

　　1. 设置窗体的背景图片，其中背景图片是24位(不包括24)以下的位图(BMP图片)，并且要设置TansparencyKey的值，一般为你背景图片的背景色，即创建不规则图片时的底色，一般设为你图片中没有的颜色。

　　这种做法的不好的地方就是背景图片一定要16位或者更低的，而且还要确保客户端的显示。如果监视器的颜色深度设置大于 24 位，则不管 TransparencyKey 属性是如何设置的，窗体的非透明部分都会产生显示问题。若要避免出现这种问题，请确保“显示”控制面板中的监视器颜色深度的设置小于 24 位。当开发具有这种透明功能的应用程序时，请牢记应使您的用户意识到此问题。

　　实现步骤如下：

　　1. 新建windows application

　　2. 选择窗体，找到BackgroundImage属性，点击打开新的窗口，选择下面的导入资源文件，选择你的不规则的BMP图片

　　3. 找到窗体的TansparencyKey，将它设置为你背景图片的背景色(如黄色)

　　4. 找到窗体的FormBorderStyle，将其设置为none，即不显示标题栏

　　5. 运行

　　<!--[endif]-->

　　2. 跟背景图片一样的图形，不过是动态加载，遍历位图以实现不规则窗体。它的原理是这样的，在Form的load事件中写方法使得窗体的描绘区域发生改变。

　　实现步骤如下：

　　1. 建立winform应用程序

　　2. 找到窗体的Load事件，双击进行编辑

　　3. 编写方法，主要的代码如下：

class BitmapRegion
    {
        public BitmapRegion()
        { }


        /// <summary>
        /// Create and apply the region on the supplied control
        /// 创建支持位图区域的控件（目前有button和form）
        /// </summary>
        /// <param name="control">The Control object to apply the region to控件</param>
        /// <param name="bitmap">The Bitmap object to create the region from位图</param>
        public static void CreateControlRegion(Control control, Bitmap bitmap)
        {
            // Return if control and bitmap are null
            //判断是否存在控件和位图
            if (control == null || bitmap == null)
                return;

            // Set our control''s size to be the same as the bitmap
            //设置控件大小为位图大小
            control.Width = bitmap.Width;
            control.Height = bitmap.Height;
            // Check if we are dealing with Form here
            //当控件是form时
            if (control is System.Windows.Forms.Form)
            {
                // Cast to a Form object
                //强制转换为FORM
                Form form = (Form)control;
                // Set our form''s size to be a little larger that the  bitmap just
                // in case the form''s border style is not set to none in the first place
                //当FORM的边界FormBorderStyle不为NONE时，应将FORM的大小设置成比位图大小稍大一点
                form.Width = control.Width;
                form.Height = control.Height;
                // No border
                //没有边界
                form.FormBorderStyle = FormBorderStyle.None;
                // Set bitmap as the background image
                //将位图设置成窗体背景图片
                form.BackgroundImage = bitmap;
                // Calculate the graphics path based on the bitmap supplied
                //计算位图中不透明部分的边界
                GraphicsPath graphicsPath = CalculateControlGraphicsPath(bitmap);
                // Apply new region
                //应用新的区域
                form.Region = new Region(graphicsPath);
            }
            // Check if we are dealing with Button here
            //当控件是button时
            else if (control is System.Windows.Forms.Button)
            {
                // Cast to a button object
                //强制转换为 button
                Button button = (Button)control;
                // Do not show button text
                //不显示button text
                button.Text = "";

                // Change cursor to hand when over button
                //改变 cursor的style
                button.Cursor = Cursors.Hand;
                // Set background image of button
                //设置button的背景图片
                button.BackgroundImage = bitmap;

                // Calculate the graphics path based on the bitmap supplied
                //计算位图中不透明部分的边界
                GraphicsPath graphicsPath = CalculateControlGraphicsPath(bitmap);
                // Apply new region
                //应用新的区域
                button.Region = new Region(graphicsPath);
            }
        }
        /// <summary>
        /// Calculate the graphics path that representing the figure in the bitmap
        /// excluding the transparent color which is the top left pixel.
        /// //计算位图中不透明部分的边界
        /// </summary>
        /// <param name="bitmap">The Bitmap object to calculate our graphics path from</param>
        /// <returns>Calculated graphics path</returns>
        private static GraphicsPath CalculateControlGraphicsPath(Bitmap bitmap)
        {
            // Create GraphicsPath for our bitmap calculation
            //创建 GraphicsPath
            GraphicsPath graphicsPath = new GraphicsPath();
            // Use the top left pixel as our transparent color
            //使用左上角的一点的颜色作为我们透明色
            Color colorTransparent = bitmap.GetPixel(0, 0);
            // This is to store the column value where an opaque pixel is first found.
            // This value will determine where we start scanning for trailing opaque pixels.
            //第一个找到点的X
            int colOpaquePixel = 0;
            // Go through all rows (Y axis)
            // 偏历所有行（Y方向）
            for (int row = 0; row < bitmap.Height; row++)
            {
                // Reset value
                //重设
                colOpaquePixel = 0;
                // Go through all columns (X axis)
                //偏历所有列（X方向）
                for (int col = 0; col < bitmap.Width; col++)
                {
                    // If this is an opaque pixel, mark it and search for anymore trailing behind
                    //如果是不需要透明处理的点则标记，然后继续偏历
                    if (bitmap.GetPixel(col, row) != colorTransparent)
                    {
                        // Opaque pixel found, mark current position
                        //记录当前
                        colOpaquePixel = col;
                        // Create another variable to set the current pixel position
                        //建立新变量来记录当前点
                        int colNext = col;
                        // Starting from current found opaque pixel, search for anymore opaque pixels
                        // trailing behind, until a transparent   pixel is found or minimum width is reached
                        ///从找到的不透明点开始，继续寻找不透明点,一直到找到或则达到图片宽度
                        for (colNext = colOpaquePixel; colNext < bitmap.Width; colNext++)
                            if (bitmap.GetPixel(colNext, row) == colorTransparent)
                                break;
                        // Form a rectangle for line of opaque   pixels found and add it to our graphics path
                        //将不透明点加到graphics path
                        graphicsPath.AddRectangle(new Rectangle(colOpaquePixel, row, colNext - colOpaquePixel, 1));
                        // No need to scan the line of opaque pixels just found
                        col = colNext;
                    }
                }
            }
            // Return calculated graphics path
            return graphicsPath;
        }
    }

 　　4. 运行<!--[endif]-->